Common Take-Home Assignments for Web3 Developer Roles

You've passed the initial screening call for a Web3 developer role. What's next? In most cases, it's the take-home assignment. This is a critical step in the interview process where a company assesses your practical coding skills, your attention to detail, and your ability to work independently.

Unlike abstract algorithm problems, a Web3 take-home assignment is designed to simulate the kind of work you would actually do in the role. Nailing this assignment is often the key to moving on to the final round. This guide covers the most common types of take-home projects you can expect for smart contract and full-stack Web3 roles.

Why Do Companies Use Take-Home Assignments?

• To Test Practical Skills: They want to see how you build a real, small-scale project from start to finish.
• To Assess Code Quality: It's a chance to evaluate your coding style, documentation, and, most importantly, your approach to testing.
• To Gauge Security Mindset: For smart contract roles, they want to see if you write secure code by default.

Pro Tip: A well-documented project with a comprehensive test suite will always stand out. Do not skip writing tests!

Common Smart Contract Developer Assignments

These assignments focus on your Solidity and EVM knowledge.

1. Build a Staking Contract:

   • The Task: Create a contract where users can deposit an ERC-20 token and earn rewards in that same token over time.
   • What it Tests: Your understanding of basic DeFi primitives, token interactions (ERC-20), and state management.
   • To Go Above and Beyond: Implement a variable reward rate or add a feature to compound rewards. Write extensive tests covering deposits, withdrawals, and reward calculation logic.

2. Build a Simple On-Chain Auction:

   • The Task: Write a contract to auction an NFT. This could be an English auction (price goes up) or a Dutch auction (price goes down).
   • What it Tests: Your ability to manage time-based logic, handle bids from multiple users, and securely transfer both ETH and an NFT.
   • To Go Above and Beyond: Implement gas optimizations and add protection against common vulnerabilities like reentrancy.

3. Find the Vulnerability:

   • The Task: You are given a piece of Solidity code that contains one or more security flaws. Your job is to identify them, explain why they are a risk, and write a fixed, secure version of the code.
   • What it Tests: Your security mindset and knowledge of common attack vectors (reentrancy, integer overflows, oracle manipulation, etc.).
   • To Go Above and Beyond: Write a test case (using Foundry or Hardhat) that successfully exploits the vulnerability in the original code, and then show that the same test fails against your fixed code. This is a very strong signal.

Common Full-Stack Web3 Developer Assignments

These assignments test your ability to connect a frontend to smart contracts.

1. Build a "Wallet Dashboard" Frontend:

   • The Task: Create a simple React/Next.js application that allows a user to connect their wallet. The app should then display their ETH balance and their balance of a few major ERC-20 tokens (like USDC and WETH).
   • What it Tests: Your proficiency with frontend frameworks and your ability to use a library like Ethers.js or Viem to read data from the blockchain.
   • To Go Above and Beyond: Add features like a transaction history viewer or a simple interface for sending ETH. Ensure the UI is clean, responsive, and handles different wallet connection states gracefully (e.g., loading, error, wrong network).

2. Build an Interface for an Existing Protocol:

   • The Task: You are given the address of a smart contract deployed on a testnet (e.g., a simple lending protocol). Your task is to build a frontend that allows users to interact with its main functions (e.g., deposit collateral, borrow, repay).
   • What it Tests: Your ability to read and understand an existing contract's ABI (Application Binary Interface) and build a user-friendly interface for it.
   • To Go Above and Beyond: Write clear and helpful UI copy that explains what each function does. Add input validation and helpful error messages.

How to Succeed

• Read the Instructions Carefully: Make sure you deliver exactly what is asked for.
• Write a Great README: Your README.md is part of the submission. Explain your design choices, any trade-offs you made, and provide clear instructions on how to set up and run your project.
• Don't Over-Engineer: It's a test, not a production system. Focus on writing clean, correct, and well-tested code that meets the requirements.

By preparing for these common scenarios, you can approach your next Web3 take-home assignment with confidence and showcase the skills that will get you hired.