Blockchain Engineering Unveiled
Jay Derenthal
Article Sections
Introduction
Choose a Path
Corporate Career Path
Startup Career Path
Roles
Blockchain Developer
Blockchain Engineer
Blockchain Architect
Headhunters
Job Boards
Blockchain
Other
Interview Preparation
Skills
Software
Cryptography and Cybersecurity
Smart Contracts
Web3
Data Analysis
Knowledge
Employer
Communities
Consensus Mechanisms
Platforms and Protocols
GitHub
Interview Q&A
Conclusion
Introduction
The blockchain industry offers exciting job opportunities as it continues to proliferate. Aspiring blockchain engineers can tailor their careers to match their passions and ambitions. Understanding the essential skills for success in this dynamic field is crucial.
Blockchain engineers conceptualize, design, and implement robust blockchain-based systems. Their expertise in cryptography, decentralized networks, and programming languages is instrumental in shaping the future of blockchain technology.
Choose a Path
Evaluate your interests and preferences to choose a career path that suits you best. Keep in mind that each path, corporate and startup, has its unique benefits and challenges. Considering these two paths, you can decide which career path aligns best with your goals, preferences, and risk tolerance.
Corporate Career Path
Secure job with a high salary, reasonable work hours, and comprehensive benefits.
Provides stability, established infrastructure, and the chance to work on large-scale projects
Opportunities with financial services giants like Barclays, Mastercard, UBS, Bank of America, and more. Major tech firms such as IBM, Microsoft, Intel, and Fujitsu also seek blockchain talent.
Government entities, consulting firms, logistics companies, healthcare providers, power utilities, and real estate brokers are hiring blockchain professionals.
Example: Joining IBM’s blockchain division to work on enterprise-level blockchain solutions for global clients.
Startup Career Path
Focus is on creating smart contracts and innovative consumer products.
Ideal for those with an entrepreneurial spirit and willingness to trade monetary compensation and work-life balance for equity or tokens.
Abundant opportunities in DeFi (decentralized finance) and NFT (non-fungible token) startups.
Offers the opportunity to be part of disruptive innovation, shape the industry, and benefit from early-stage equity or token ownership.
Example: Joining a DeFi startup that aims to revolutionize lending and borrowing using blockchain technology.
Roles
“Blockchain Developer,” “Blockchain Engineer,” and “Blockchain Architect” are distinct roles within the field of “Blockchain Engineering.” Each role brings unique expertise, but they often collaborate to ensure blockchain solutions are technically robust and precisely aligned with the project’s objectives.
While each title can represent a specific phase in a blockchain project’s lifecycle, their involvement is not strictly chronological. For instance, a Blockchain Architect might primarily lay the foundational structure at the onset yet re-engage during later stages to address scalability and integration. Conversely, a Blockchain Developer’s involvement might span from the project’s inception to its conclusion.
Blockchain Developer
Translates conceptual ideas into fully functional blockchain applications.
Proficient in programming languages such as Solidity, Go, Rust, and JavaScript.
Familiar with tools to create user interfaces and integrate with blockchain backends.
Blockchain Engineer
Focuses on building, deployment, and optimization of blockchain solutions.
Has expertise in setting up and managing nodes, understanding the intricacies of peer-to-peer networks, and employing decentralized storage solutions like IPFS.
Proficient in seamlessly integrating smart contracts with web interfaces and other platforms.
Blockchain Architect—Planning and Scalability Phase
Responsible for designing the overall structure and framework of blockchain systems.
Possesses extensive knowledge of blockchain technology, consensus mechanisms, and data storage.
Creates scalable and robust blockchain architectures tailored to project requirements.
Provides blueprints for successful and sustainable blockchain implementations.
Headhunters
Collaborating with blockchain and crypto headhunters, aka “recruiters,” enhances your career prospects. These specialized headhunters have industry knowledge and connections and function as trusted advisors. They tailor their search to your skills, experience, and desired work environment. Using their network, they connect you with potential employers, facilitate interviews, and offer guidance during negotiations.
Below are the leading blockchain technology headhunters:
Job Boards
Blockchain-focused
Niche job boards, such as those listed below, vary in levels of platform activity. Check job boards and other job post resources as regularly as you deem appropriate for each one. Follow your favorites on Twitter and Telegram and engage with them on their Discord channels.
Other Job Boards
The job board websites listed below are not blockchain-specific. They do, however, list blockchain engineering jobs. You can subscribe to email alerts for your specific job search to save time.
Interview Preparation
Maximize your chances of success in job interviews by showcasing your skills, knowledge, passion, curiosity, and commitment to blockchain engineering.
Skills
Several valuable skills and areas of knowledge will enhance your career prospects in blockchain engineering. While you don’t need to be proficient in all of them, having a solid understanding of dApp (decentralized application) technology is a prerequisite.
Develop a deep understanding of common blockchain terminologies, such as decentralized finance (DeFi), non-fungible tokens (NFTs), and cryptographic protocols.
Acquire knowledge in areas crucial to blockchain engineering, including failure mode handling, anomaly detection, performance management, and threat analytics.
Understand best practices for security, privacy, and data integrity in blockchain systems.
Be prepared to discuss your experience in troubleshooting and resolving technical challenges related to blockchain development.
Software
Build the foundation for pursuing your career in blockchain engineering by developing a fundamental understanding of the following:
Backend Development: Python, Java, C#, Ruby, Node.js
Frontend Development: React, Angular, JavaScript, Vue.js
Debugging, encryption, and distributed architecture.
Cryptographic protocols and cryptocurrency mining fundamentals.
Hashing: Understanding the principles and applications of hash functions in blockchain.
Blockchain software principles across different platforms.
Elliptic curve signatures and Merkle proofs.
Cybersecurity and its role in safeguarding information, protecting data, and ensuring a secure working environment for web3 projects.
Smart Contracts
Become well-versed in programming components essential for developing smart contracts and building decentralized applications (dApps):
Languages and Technologies: Solidity, Rust, Vyper, Ganache, Geth, Parity, Metamask, IPFS
Tools: Chainlink, Remix, OpenZeppelin
Frameworks: Hardhat, Truffle, Brownie, Dapps.tools, Embark
Testnets: Ropsten, Rinkeby, Kovan, Görli
Familiarize yourself with popular platforms like Ethereum and learn the Solidity programming language. Understand Solidity’s syntax, data structures, and features to create and deploy smart contracts on the Ethereum network.
Explore alternative platforms like Solana and learn the specific programming languages and frameworks used for smart contract development on these platforms.
Keep up to date with advancements in smart contract technology, such as the integration of zero-knowledge proofs through zk-SNARKS.
Gain practical experience by building and deploying smart contracts. Participate in online coding tutorials, join developer communities, and contribute to open-source projects related to smart contract development.
Stay informed about best practices for smart contract security and learn about techniques such as code auditing, formal verification, and secure coding practices.
Web3
Web3 represents the next evolution of the internet, constructed on decentralized networks like blockchain.
Web3 user interaction with blockchain platforms fundamentally differs from traditional Web2 systems, leading to intriguing UI/UX design challenges as customer behavior takes a distinct shape. You should grasp traditional web design principles and prepare for the unique challenges and opportunities Web3 brings.
Data Analysis
The essence of blockchain technology revolves around data movement. So, even if data analysis is not your primary focus, having a basic understanding of it in the context of blockchains can prove valuable in cultivating a robust blockchain engineering résumé.
Proficiency in Data Analysis allows you to interpret and analyze data, predict market trends, and make informed decisions. Data Analysts play a critical role in providing insights that drive strategic actions across the blockchain industry, often harnessing artificial intelligence (AI) and machine learning (ML) tools to enhance their capabilities.
Knowledge
Research the Employer’s Technology and Applications
Tailor your approach to the specific company and role you are applying for, emphasizing how your skills and experiences align with their needs and goals.
Study the business model and value proposition of the company or organization.
Delve into the technology stack and solutions the company or organization offers.
Understand their blockchain implementation, including smart contract platforms and scalability solutions.
Identify their blockchain solution’s unique properties and advantages compared to competitors.
Familiarize yourself with use cases and industry-specific applications relevant to their product or service offerings.
Explore their previous projects and case studies to grasp the practical applications of their technology in various industries.
Communicate your genuine interest in the company’s blockchain technology and how it aligns with your career goals.
Deepen your involvement in blockchain communities
Discuss your active participation in blockchain communities, including code-sharing platforms like GitHub or GitLab.
Highlight your contributions, projects, or collaborations within these communities.
Mention any meetups, workshops, or conferences you have attended and share the key takeaways and insights you gained from those events.
Keep informed about industry trends, news, and blockchain technology discussions.
Follow prominent figures and influencers in the blockchain space to gain insights and stay connected with emerging developments. Read blog and Twitter posts from prominent figures like Vitalik Buterin.
Research companies, connect with professionals already in the field, and consider internships or freelance projects to gain practical experience and further refine your career goals.
Attend conferences and meetups and continue learning to position yourself for success.
Consensus Mechanisms
Understand the different approaches to achieving consensus in blockchain networks. Consensus mechanisms play a critical role in validating and adding transactions to the blockchain while impacting security, scalability, and performance in blockchain networks.
Proof of Work (PoW): The most well-known consensus mechanism. Used by Bitcoin and many other cryptocurrencies.
Proof of Stake (PoS): An energy-efficient alternative to PoW, where validators are chosen based on the number of coins they hold.
Delegated Proof of Stake (DPoS):
Relies on a small group of elected delegates to validate transactions.
Delegates are chosen through voting by coin holders and take turns validating blocks.
Provides faster transaction confirmation times but may be perceived as less decentralized due to the smaller group of validators.
Byzantine Fault Tolerance (BFT):
Designed to tolerate malicious nodes or Byzantine faults.
Used in permissioned blockchains and enterprise solutions to establish trust among participants.
Proof of Authority (PoA):
Relies on a set of approved validators who are known and trusted entities.
Validators take turns adding blocks to the blockchain based on their authority.
Commonly used in private or consortium blockchains.
Practical Byzantine Fault Tolerance (PBFT): Enables a distributed system to tolerate Byzantine faults, making it suitable for permissioned blockchain networks.
Delegated Byzantine Fault Tolerance (dBFT): Like DPoS, relies on a small group of delegates to validate transactions. However, unlike DPoS, dBFT does not involve voting and instead uses a deterministic algorithm to select the next validator.
Directed Acyclic Graph (DAG): Transactions are in a graph-like structure without traditional blocks, allowing for scalability and parallel processing.
Platforms and Protocols
Below is an overview of popular blockchain platforms and protocols that can serve as a starting point for your exploration. Some of these platforms and protocols have dedicated job boards, offering opportunities for entry-level positions. Be sure to gain a comprehensive understanding of a platform or protocol as you prepare for an interview.
Algorand (ALGO)
High transaction throughput and fast confirmation time using Pure Proof-of-Stake (PPoS) consensus algorithm for decentralization, security, scalability.
Job applicant focus: Familiarize with PPoS and smart contract development.
Arweave (AR)
Permanent storage network aiming to store data indefinitely on the blockchain using Proof-of-Access (PoA) consensus mechanism.
Job applicant focus: Familiarize with PoA and storage and retrieval protocols.
Avalanche (AVAX)
Speed, interoperability, and scalability are extended via the Avalanche consensus protocol for subnets for custom blockchains.
Job applicant focus: Familiarize with Avalanche consensus protocol, building subnets, and dApp development.
Binance Chain (BNB)
Blockchain platform with capabilities for tokenization, dApps, and cross-chain interoperability using a variant of the Tendermint consensus algorithm.
Job applicant focus: Familiarize with Tendermint, Binance Chain ecosystem, smart contract development.
Bitcoin (BTC)
Proof-of-work (PoW) consensus mechanism with hashing algorithms like SHA-256 for mining.
Transactions secured through digital signatures, ensuring transaction authenticity, integrity, and non-repudiation.
Scripting language ‘Script’ enables complex transaction types, including multi-signature wallets, time-locked transactions, and smart contracts via second-layer solutions like Rootstock (RSK).
Segregated Witness (SegWit) upgrade optimizes block space utilization and enables Lightning Network for faster and cheaper transactions.
Scaling challenges prompted research into off-chain transaction networks, layer-two protocols, sidechains.
Job applicant focus:
Understand Bitcoin’s PoW consensus mechanism, including underlying hashing algorithms and use of digital signatures for transaction security.
Familiarize with Script and its use cases.
Stay updated on SegWit upgrades and Lightning Network developments.
Deepen understanding of Bitcoin’s scalability challenges and explore proposed solutions such as off-chain transaction networks, layer-two protocols, sidechains.
Stay informed about privacy-enhancing technologies and advancements in smart contract integration.
Cardano (ADA)
Focus on security, scalability, and sustainability using Ouroboros consensus mechanism.
Job applicant focus: Familiarize with ecosystem dApps, Ouroboros, smart contract platform, Plutus programming language.
Chainlink (LINK)
Oracle network connecting smart contracts with real-world data and external APIs.
Job applicant focus: Familiarize with Chainlink’s oracle network, data integration, oracle solutions for smart contracts.
Corda
Distributed ledger platform designed for financial institutions and regulated industries.
Job applicant focus: Familiarize with Corda’s privacy features, legal contract modeling, open-source ‘R3’ platform for business interoperability.
Cosmos (ATOM)
Decentralized network of independent blockchains enabling interoperability via Tendermint consensus algorithm and Inter-Blockchain Communication (IBC) protocol.
Job applicant focus: Familiarize with Tendermint consensus algorithm, interchain applications, IBC.
EOS
Designed for development and execution of dApps using delegated proof-of-stake (DPoS) consensus mechanism for scalability and usability.
Job applicant focus: Familiarize with EOSIO software, DPoS, smart contract development.
Ethereum (ETH)
Decentralized platform enabling smart contracts and dApps.
Transitioned to proof-of-stake (PoS) consensus through Ethereum 2.0.
Supports Solidity programming language and a wide range of tokens and projects.
Job applicant focus:
Familiarize with Ethereum’s smart contract development, Ethereum Virtual Machine (EVM), Solidity programming language, development ecosystem.
Learn about Ethereum’s Gas mechanism and how it affects transaction fees and computational costs.
Understand Ethereum’s PoW and PoS consensus mechanisms.
Stay updated with network upgrades and improvements, such as London hard fork and upcoming EIPs (Ethereum Improvement Proposals).
Explore Ethereum’s ecosystem of dApps, DeFi protocols, NFTs, DAOs (Decentralized Autonomous Organizations).
Engage with the Ethereum community through forums, developer documentation, Ethereum-focused events and hackathons.
Fantom (FTM)
Fast and scalable platform designed for dApps.
Job applicant focus: Explore Fantom’s consensus mechanism ‘Lachesis’ and its DAG (Directed Acyclic Graph) structure for fast transaction processing.
Filecoin (FIL)
Decentralized storage network that enables users to buy and sell storage space.
Job applicant focus: Learn about Filecoin’s storage and retrieval markets, proof-of-replication (PoRep), proof-of-spacetime (PoST).
Flow (FLOW)
• Fast, decentralized, developer-friendly blockchain designed as foundation for new generation of games, apps, and digital assets that power them.
• Job applicant focus: Dive into Flow's unique multi-role architecture, resource-oriented programming with Cadence, ecosystem's emphasis on consumer-friendly onboarding and user experiences.
Hedera Hashgraph
DAG consensus algorithm achieves high throughput and fast transaction finality.
Familiarize with core concepts of hashgraph technology, including virtual voting, virtual gossip about gossip, asset tokenization.
Hyperledger Fabric
Open-source enterprise-grade platform for business networks offering modular architecture, privacy, permissioned transactions.
Job applicant focus: Familiarize with Hyperledger Fabric’s architecture, chaincode development, enterprise systems blockchain integration.
IOTA (IOTA)
DAG platform focused on the Internet of Things (IoT) and machine-to-machine (M2M) transactions using Tangle, a unique data structure, instead of traditional blockchain.
Job applicant focus: Familiarize with Tangle, IoT integration, applications development for M2M transactions.
Litecoin (LTC)
Cryptocurrency based on Bitcoin protocol with faster block generation times and different hashing algorithm.
Job applicant focus: Familiarize with Scrypt proof-of-work algorithm, transaction processing.
Monero (XMR)
Privacy-focused cryptocurrency with strong emphasis on anonymity.
Job applicant focus: Familiarize with privacy-enhancing features of CryptoNote protocol and transaction obfuscation.
NEAR Protocol (NEAR)
Focuses on low fees, fast transactions, developer-friendly environment for dApps.
Job applicant focus: Familiarize with architecture, AssemblyScript for smart contracts, Nightshade consensus mechanism.
NEM (XEM)
Focused on simplicity, speed, scalability.
Job applicant focus: Familiarize with Proof-of-Importance (PoI) consensus algorithm and use cases like supply chain management and identity verification.
NEO (NEO)
Smart contract platform supporting multiple programming languages and digital identity solutions.
Job applicant focus: Familiarize with dBFT (Delegated Byzantine Fault Tolerance) consensus mechanism.
Ontology (ONT)
Dual-layer architecture for scalability and interoperability with identity verification and authentication mechanisms.
Job applicant focus: Familiarize with consensus algorithm combining Proof of Stake (PoS) and Byzantine Fault Tolerance (BFT).
Origin Protocol (OGN)
Platform for creating and managing decentralized marketplaces, fractional ownership, identity verification, dispute resolution.
Job applicant focus: Familiarize with IPFS (InterPlanetary File System) for data storage.
Polkadot (DOT)
Multi-chain platform enabling interoperability between different blockchains using nominated proof-of-stake (NPoS) consensus algorithm for relay chain.
Job applicant focus: Familiarize with NPoS, building parachains, cross-chain communications.
Polygon (MATIC)
Layer 2 scaling solution for Ethereum, providing fast and cheap transactions.
Job applicant focus: Familiarize with Polygon’s architecture, Proof-of-Stake (PoS) consensus mechanism, Polygon SDK, Polygon Bridge.
Ripple (XRP)
Payment protocol facilitating fast and low-cost international money transfers.
Job applicant focus: Familiarize with payment protocol, cross-border transactions, financial systems integration.
Solana (SOL)
Fast blockchain platform for dApps and scalable infrastructure using proof-of-history (PoH) consensus mechanism.
Job applicant focus: Familiarize with Solana’s architecture and PoH approach to scalability and performance, Solana ecosystem.
Stellar (XLM)
Platform for fast, low-cost cross-border transactions using Stellar Consensus Protocol (SCP).
Job applicant focus: Familiarize with SCP and Stellar DEX (decentralized exchange).
Tezos (XTZ)
Self-amending blockchain enabling on-chain governance and formal verification using Liquid Proof-of-Stake (LPoS) consensus mechanism.
Job applicant focus: Familiarize with LPoS, on-chain governance, smart contract development.
The Graph (GRT)
Decentralized indexing protocol for querying data from blockchains.
Job applicant focus: Familiarize with:
Subgraph technology for querying and indexing specific data sets from various blockchains
Network of indexers, curators, delegators.
Theta (THETA)
·Decentralized video delivery network.
Job applicant focus: Familiarize with decentralized video delivery networks, Theta’s unique approach, potential use cases beyond video streaming.
Tron (TRX)
Uses delegated proof-of-stake (DPoS) consensus mechanism for faster transaction processing.
Job applicant focus: Familiarize with DPoS, dApp ecosystem, dApps development.
VeChain (VET)
Focused on supply chain management and product authenticity verification using proof-of-authority (PoA) consensus mechanism for fast and efficient transactions.
Job applicant focus: Familiarize with PoA, supply chain use cases, Internet of Things (IoT) technology solutions for product authentication and tracing.
Zilliqa (ZIL)
Sharding technology enables high throughput and network scalability.
Job applicant focus: Familiarize with Scilla smart contract language and Practical Byzantine Fault Tolerance (PBFT) consensus mechanism.
GitHub
Effectively using GitHub can significantly enhance your chances of securing a position. When applying for blockchain engineering positions, include a link to your GitHub profile in your resume or cover letter. Allow recruiters and hiring managers to review your work directly and assess your capabilities.
Below is a summary of leveraging GitHub during your job application process. If you are not at the point in your blockchain career to have this in place, just be familiar with the items below and be prepared to discuss how you plan to work on them as you build your career.
Showcase your projects: Create a GitHub account and populate it with your relevant blockchain projects. Upload your code repositories, smart contracts, and any other relevant work you have done in the blockchain field. Allow potential employers to assess your skills and abilities.
Maintain a clean and organized profile: Organize your repositories, ensuring they are well-documented, easily understandable, and properly labeled. Employers appreciate a well-structured profile that demonstrates your professionalism and attention to detail.
Collaborate on open-source projects: Contribute to popular blockchain-related open-source projects on GitHub. Demonstrate your coding skills and showcase your ability to work in a team and contribute to a larger community. This also allows potential employers to see your coding style and the value you can bring to their projects.
Share your knowledge and insights: Use GitHub to publish informative articles, tutorials, or documentation related to blockchain development. Showcase your expertise and commitment to the blockchain community. This also helps establish you as a thought leader and can attract the attention of potential employers.
Participate in discussions: Engage in discussions and forums related to blockchain development on GitHub. Contribute your insights, provide feedback on issues, and collaborate with other developers. Demonstrate your active involvement in the community and your passion for blockchain technology.
Interview Q&A Prep
You may be asked screening questions like the ones below in round one or round two of your application process. Remember, an interview is a two-way conversation. Don’t hesitate to inquire about the organization’s team, culture, goals, KPIs, expectations, and vision. If you join the protocol, this approach empowers you to make informed decisions and sets you up for success.
General Questions:
Question: What is a distributed ledger?
Answer: A distributed ledger is a database spread across multiple nodes or devices in a network. In a blockchain, each node has a copy of the entire ledger, and all nodes work together to reach a consensus on the validity of transactions. This distributed nature of the ledger ensures security, transparency, and resilience against single points of failure.
Question: What is a blockchain?
Answer: A blockchain is a decentralized and immutable digital ledger that records transactions across a network of computers. It operates on a consensus mechanism, where multiple nodes agree on the validity of each transaction, ensuring security and transparency. Each block in the chain contains a batch of transactions, cryptographically linked to the previous block, forming a chronological data sequence. Once a block is added to the chain, it cannot be altered, providing an unchangeable record of all past transactions. This technology has transformed various industries, enabling secure peer-to-peer transactions, supply chain management, digital asset ownership, and much more without intermediaries or central authorities.
Question: What is the difference between public and private blockchains?
Answer: Public blockchains are open to anyone worldwide, while private blockchains are accessible only to authorized users, often used internally by companies.
Question: What is the difference between a public key and a private key?
Answer: A public key is a public identifier derived from the private key, used to receive transactions and verify the signature. A private key is a secret key used to sign transactions on the blockchain, providing cryptographic proof of ownership. While the public key can be easily shared with others to receive funds, the private key must be kept entirely confidential, as it grants access and control over the associated blockchain assets.
Question: What is a smart contract?
Answer: A smart contract is a self-executing contract with terms directly written in code. It enables various applications beyond buying and selling, such as borrowing against collateral or transferring digital assets in a peer-to-peer manner without intermediaries.
Question: What is the difference between a dApp and a traditional app?
Answer: A traditional application is centralized and controlled by a single entity, while a dApp is decentralized and operates on the blockchain, leveraging the benefits of decentralization.
Question: What is the difference between a token and a coin?
Answer: Coins are native assets of a blockchain (e.g., BTC, ETH), while tokens are additional assets created on top of another blockchain (e.g., LINK, GRT, AAVE).
Question: What is a consensus algorithm?
Answer: A consensus algorithm is a mechanism enabling multiple nodes in a distributed system to agree on the system’s state. Examples include Proof of Work (PoW), Proof of Stake (PoS), and Proof of History.
Question: What is a node?
Answer: A node is a computer or device that participates in the blockchain network by validating transactions and maintaining a local copy of the blockchain. Nodes may have various roles depending on the network, but their contributions are essential to the network’s functioning.
Question: What is proof-of-work (PoW)?
Answer: Proof-of-work (PoW) is a consensus algorithm used by some blockchains, where miners compete to solve complex mathematical problems to validate transactions and create new blocks.
Miners compete to solve mathematical puzzles using computational power.
The first miner to solve the puzzle gets the right to create and add the next block to the blockchain.
Difficulty of puzzles adjusts to maintain a consistent block creation rate.
Miners are rewarded with native crypto for their computational work, incentivizing participation and blockchain security.
PoW is resource-intensive, requiring significant computational power, making it costly and time-consuming.
PoW was widely used in early blockchain technology, with Bitcoin as the first and now most famous example.
Criticisms include high energy consumption, potential for mining power centralization, and scalability challenges.
Question: What is proof-of-stake (PoS)?
Answer: Proof-of-stake (PoS) is a consensus algorithm used by some blockchains, where validators participate in the consensus process by staking their tokens.
Economic incentives and disincentives secure the blockchain and reach a consensus in PoS:
Validators are chosen based on the number of tokens they hold and are willing to stake as collateral.
More staked tokens increase a validator’s chances of being chosen to create a new block and receive rewards.
Validators can lose their staked tokens if they behave maliciously or attempt to attack the system.
Slashing penalties and delegation are used in various PoS-based blockchains to promote a more distributed and secure network.
PoS and Layer 2s built on PoS blockchains have gained popularity as a greener, more scalable alternative to PoW for securing blockchain networks.
Criticisms include the “rich get richer” phenomenon and potential centralization, known as the “Nothing at Stake” problem:
Large stake validators are incentivized to accumulate more tokens, potentially leading to centralization.
Centralization can compromise the decentralized nature and security of the blockchain.
Question: What is a 51% attack?
Answer: A 51% attack occurs when a single entity or group of entities controls more than 50% of the computing power (hashrate) in a blockchain network. With majority control, the attackers can manipulate transactions, double-spend coins, and potentially compromise the integrity of the network. Having 51% of the network’s hashrate allows the attackers to outpace the honest nodes and impose their version of the blockchain’s history.
Question: What is a blockchain fork?
Answer: A blockchain fork occurs when two or more blocks are added to the chain simultaneously, creating two or more versions of the blockchain.
Question: What is a soft fork?
Answer: A soft fork occurs when a blockchain is updated to enforce new rules, but the old rules are still valid. In this case, the new rules are backward compatible with the old ones, meaning nodes not upgraded can still function within the network.
Question: What is a hard fork?
Answer: A hard fork occurs when a blockchain is split into two chains with different rules and protocols. This can happen when the community disagrees with a major update or change to the blockchain’s underlying protocol, leading to the creation of a new chain with its own set of rules.
Question: What is Ethereum ‘gas’?
Answer: Gas is the unit used to measure the computational effort required to execute a transaction or smart contract on the Ethereum blockchain. Each operation on the EVM consumes a certain amount of gas, and users must pay a corresponding gas fee to execute their transactions.
Question: Why is gas important from a security perspective in blockchain?
Answer: Gas plays a crucial role in ensuring the security and efficiency of the Ethereum blockchain. By requiring users to pay for the computational resources they consume, gas fee disincentivizes malicious actors from congesting the network or attempting to take control of it. Any such effort would incur a significant gas fee, making it economically unfeasible to launch large-scale attacks.
Question: What is an Ethereum Virtual Machine (EVM)?
Answer: The Ethereum Virtual Machine (EVM) is a virtual machine that runs on the Ethereum blockchain, allowing for the execution of smart contracts. It serves as the runtime environment for smart contracts, providing a sandboxed and isolated environment for their execution.
Question: What is a Merkle tree?
Answer: A Merkle tree is a tree-like data structure used to verify the integrity of large data sets efficiently. It allows for the efficient mapping and validation of data within a block or a set of blocks. The Merkle tree enables quick verification of whether a specific piece of data is in a block without downloading the entire block.
Question: What is a nonce?
Answer: A nonce is a random number used in the proof-of-work consensus algorithm to find a valid hash for a block. Miners modify the nonce value repeatedly during the mining process until they find a hash that meets the required difficulty level. The nonce allows miners to create unique hashes for each block attempt.
Question: What is the difference between Web2 and Web3?
Answer: Web2 refers to the current centralized internet controlled by large corporations, whereas Web3 is the decentralized evolution empowering users to control their data and interactions: Web2 and Web3 represent different generations and paradigms of the internet.
Web2 (The Social Web): Transition from static web pages (Web1) to dynamic, user-generated content.
User-generated Content: Social networking websites allow users to create, modify, share, and review content.
Centralization: Key services are primarily owned by a few big tech companies.
Advertising Monetization: User data is often used to target ads, making the user the product.
APIs: Combining multiple services into single applications.
Ajax: Interactive web applications.
Web3 (The Decentralized Web): Internet based on decentralized protocols and technologies, most notably blockchain.
Decentralization: Peer-to-peer networks with no central authority.
Cryptography: Public and private keys ensure security, privacy, and digital ownership.
Tokenomic Monetization: Cryptocurrencies and tokens enable direct monetization and value transfer.
Sovereignty: Users have full control over their own data, identities, and transactions.
Interoperability: Projects and networks can communicate and share value.
Trustless Transactions: Smart contracts enable secure transactions without intermediaries.
Programmable Assets: Assets like digital art or domain names can have programmable behaviors or properties.
Language Specific Questions:
As you progress to the more technical rounds, the focus shifts towards specific programming knowledge and your logical thinking prowess. There may be a coding round where you are presented with specific problems to solve in a live setting. This test aims to assess your coding prowess and ability to think logically and analytically, so think out loud and explain your thinking process while trying to solve a problem.
Solidity
Solidity is a high-level programming language primarily used for developing smart contracts on the Ethereum blockchain. Once written in Solidity, smart contracts are compiled into bytecode, which is then executed by the Ethereum Virtual Machine (EVM) on the chain.
As the most popular language for creating smart contracts on Ethereum, Solidity is specifically designed for the platform, enabling secure and efficient execution of decentralized applications (dApps), token creation and management, automated contracts for financial transactions, and establishment of digital identities.
Due to its ability to facilitate the secure and transparent execution of smart contracts, Solidity has gained widespread adoption among blockchain developers. It is prominently used in a diverse array of dApps. Besides Ethereum, Solidity finds application in other blockchain platforms such as Binance Smart Chain and Polygon.
As the adoption of blockchain technology continues, the demand for skilled Solidity developers is expected to rise, making it a highly valued skill set in the industry. Mastering Solidity opens up numerous opportunities for creating innovative solutions in the rapidly evolving blockchain landscape.
Solidity Q&A
Question: What is Solidity?
Answer: Solidity is a high-level programming language specifically designed for writing smart contracts on the Ethereum blockchain.
Question: What is the difference between public, private, and internal functions in Solidity?
Answer: Public functions can be called by any account on the blockchain, while private functions can only be called by the contract itself. The contract and its derived contracts can call internal functions. Additionally, external functions can only be called outside the contract but not by other contract functions.
Question: What is the difference between an interface and a contract in Solidity?
Answer: In Solidity, an interface is *a way to define the functions and events of a contract without implementing them. In contrast, a contract is a complete implementation of a smart contract that can be deployed to the blockchain.
What is “gas” in Solidity?
Answer: In Solidity, gas is a unit of measurement used to calculate the cost of executing functions and transactions on the Ethereum blockchain. Each operation in a contract has a gas cost associated with it, which is paid for by the user.
Question: What is the difference between a payable and a non-payable function in Solidity?
Answer: In Solidity, a payable function can receive ether as part of a transaction, while a non-payable function cannot.
Question: What is the difference between a state variable and a local variable in Solidity?
Answer: In Solidity, a state variable is a variable that is permanently stored on the blockchain and can be accessed by any function within a contract. In contrast, a local variable is only accessible within the scope of the function in which it is defined?
Question: What is the difference between view and pure functions in Solidity?
Answer: In Solidity, view functions do not modify the state of the blockchain and only read data from it, while pure functions do not read or modify the state but only perform computations on inputs.
Question: What is a fallback function in Solidity?
Answer: The fallback function in Solidity is a function that is automatically called when a contract receives ether or when a function call does not match any of the contract’s other functions.
Question: What is a modifier in Solidity?
Answer: A modifier is a function in Solidity that can be used to change the behavior of another function within a contract. It is often used to add more security or access control to functions.
Question: What is the difference between storage and memory in Solidity?
Answer: In Solidity, storage refers to persistent data stored on the blockchain. In contrast, memory refers to temporary data that is used during function execution and is not stored on the chain.
Question: What is the difference between a struct and an array in Solidity?
Answer: In Solidity, a struct is a custom data type that can contain multiple values of different data types, while an array is a collection of multiple values of the same data type.
Question: What is an event in Solidity?
Answer: In Solidity, an event is a way for a contract to communicate with the outside world by emitting a log that external applications can read. They are often used to notify external systems of important events that occur within a contract.
Question: What is inheritance in Solidity?
Answer: In Solidity, inheritance is a way for one contract to inherit the properties and functions of another contract. This can be used to create more complex contracts and reduce code duplication.
Question: What is a constructor in Solidity?
Answer: In Solidity, a constructor is a special function within a contract that is called only once when the contract is first deployed to the blockchain. It is used to initialize the contract’s state variables.
Question: What is visibility in Solidity?
Answer: In Solidity, visibility refers to the accessibility of a function or state variable within a contract. Solidity has four visibility modifiers: public, private, internal, and external.
Question: What is the purpose of the require statement in Solidity?
Answer: The require statement in Solidity checks the inputs to a function and reverts the transaction if certain conditions are unmet. It is often used to add input validation and prevent errors in the contract.
Question: What is mapping in Solidity?
Answer: In Solidity, mapping is a data structure associating keys with values. It is often used to store and retrieve data in a contract.
Question: What is the purpose of the selfdestruct function in Solidity?
Answer: The selfdestruct function in Solidity is used to destroy a contract and transfer its remaining ether to a designated address. It is often used to reduce the storage costs of a no longer needed contract.
Rust
Rust is widely used for building dapps and protocols requiring high security and performance levels. For instance, the Polkadot network, which enables interoperability between blockchains, is built primarily with Rust and the substrate framework. Other blockchain projects that use Rust include Parity, substrate, and Arweave. Given its robust performance, safety features, and growing ecosystem of libraries and tools, Rust is increasingly becoming a popular language for blockchain developers.
Rust Q&A
What are some key features of Rust?
Answer:
• Ownership model
• Memory safety
• Zero-cost abstractions
• Thread safety
Question: What is the ownership model in Rust?
Answer: The ownership model is a way to manage memory and ensure memory safety. In Rust, every value has an owner, and there can only be one owner at a time. When the owner goes out of scope, the value is automatically dropped, and its memory is freed.
Question: What is a reference in Rust?
Answer: A reference is a way to borrow a value without taking ownership of it. References pass values between functions without copying them and allow multiple functions to access the same value.
Question: What are “lifetimes” in Rust?
Answer: Lifetimes are a way to ensure that borrowed values do not outlive the values they borrow from. They are used to prevent memory errors such as use-after-free and dangling pointers.
Question: What is a trait in Rust?
Answer: A trait is a way to define a set of methods that can be implemented by any type. Traits are used to define interfaces and to enable generic programming.
Question: What is pattern matching in Rust?
Answer: Pattern matching is a way to destructure and match values against patterns. It is often used to handle multiple cases in a concise and readable way.
Question: What are a struct and an enum in Rust?
Answer: A struct is a custom data type containing multiple values of different data types, while an enum is a custom data type representing a fixed set of values.
Question: What is the purpose of the Option type in Rust?
Answer: The Option type in Rust is a way to represent the absence of a value. It is often used to handle errors and to allow functions to return either a value or an error.
Question: What is the difference between a mutable and immutable reference in Rust?
Answer: A mutable reference in Rust allows the borrowed value to be modified, while an immutable reference only allows the borrowed value to be read. Rust’s ownership and borrowing model ensures that mutable references are exclusive and no data races exist.
Vyper
Vyper is another high-level language designed explicitly for smart contract development on Ethereum. It serves as an alternative to Solidity, providing a contract-oriented language with a syntax that is easy to read and write.
Vyper’s primary focus is on enhancing security, making it an excellent choice for developing smart contracts requiring high trust and reliability.
One of the significant advantages of Vyper over Solidity is its simplicity, as its intentionally minimalistic syntax makes it easier for auditors to read and understand the code. Additionally, Vyper has built-in security features that prevent developers from making common mistakes that could lead to security vulnerabilities.
Besides Ethereum, Vyper can also be used to develop smart contracts on other blockchain platforms that support the EVM.
Vyper Q&A
Question: What is Vyper?
Answer: Vyper is a smart contract programming language for Ethereum designed to be secure, simple, and auditable.
Question: What is the difference between Vyper and Solidity?
Answer: Vyper is designed to be simpler and more secure, and it does not support certain features present in Solidity, such as inheritance or operator overloading.
Question: What are some key features of Vyper?
Answer: Some key features of Vyper are: 1. Focus on security, simplicity, and readability and, 2. Emphasis on avoiding complex or unsafe features.
Question: What is the difference between a public and a private function in Vyper?
Answer: A public function in Vyper can be called from outside the contract, while a private function can only be called from within the contract.
Question: What is the difference between the send and transfer functions in Vyper?
Answer: The send function in Vyper is used to send ether to an address, while the transfer function is used to send ether to an address and revert the transaction if the transfer fails. The transfer function is considered safer because it avoids the reentrancy vulnerability of the send function.
Question: What is the purpose of the @payable decorator in Vyper?
Answer: The @payable decorator indicates that a function can receive ether as part of a transaction.
Question: What is the purpose of the @constant decorator in Vyper?
Answer: The @constant decorator indicates that a function does not modify the state of the contract and can be called without creating a transaction.
Question: What is the purpose of the assert statement in Vyper?
Answer: The assert statement in Vyper is used to check a condition and revert the transaction if it is not true. It is often used to add input validation and prevent errors in the contract.
Conclusion
Embarking on a successful blockchain engineer career requires more than technical ability. It requires a broad understanding of blockchain technology and a passion for innovation. By continuously expanding your knowledge and staying updated on the latest developments in the field, you can position yourself as a sought-after professional in the blockchain industry.
Leverage online platforms and networking opportunities. Showcase your skills and ability by participating in blockchain communities, attending industry events, and contributing to open-source projects. These activities demonstrate your technical abilities and help you build valuable connections with like-minded professionals and potential employers.
Furthermore, don’t underestimate the power of continuous learning and professional development. The blockchain industry is constantly evolving, and staying ahead of the curve is crucial. Engage in ongoing education, pursue relevant certifications, and explore emerging blockchain trends and technologies. By showing your commitment to growth and adaptability, you will stand out as a candidate who is well-prepared to tackle the challenges and opportunities that lie ahead in the dynamic world of blockchain engineering.
By combining technical ability, a passion for blockchain, active engagement in the industry, and a commitment to continuous learning, you can position yourself for a successful and fulfilling career as a blockchain engineer. Embrace the opportunities, stay curious, and never stop exploring the vast potential of blockchain technology.
—Article by Jay Derenthal
Copyright © 2021 Jay Derenthal. All rights reserved.