Technical & Behavioral Interview Prep

The typical Web3 interview loop

Expect 3–5 stages over 1–3 weeks:

1. Recruiter / founder screen (30 min) — motivation, salary, basic fit.
2. Technical screen (60–90 min) — live coding or take-home.
3. System / protocol design (60 min) — only for mid+ roles.
4. Security or domain deep-dive (60 min) — for devs and auditors.
5. Culture fit (30–45 min) — async work, ownership, ego check.

For developers

Live coding

You will usually solve a problem in Solidity, Rust or TypeScript on a shared editor. Common asks:

• Implement a minimal ERC-20 / ERC-721 from memory.
• Build a vesting contract with a cliff and monthly release.
• Spot the bug in a given smart contract.

How to prepare:

• Re-implement OpenZeppelin's basic contracts from scratch, without looking. Twice.
• Practice 10 small Solidity puzzles on platforms like Ethernaut, Damn Vulnerable DeFi and Cyfrin Updraft.
• For Rust/Solana: build a basic SPL token program and a simple Anchor program.

dApp / protocol architecture

You will be asked to design something — for example: "How would you build a permissionless lending protocol for a single asset?" Structure your answer:

1. Goals & non-goals — what is in scope.
2. On-chain components — contracts, storage, access control.
3. Off-chain components — indexers, keepers, frontends.
4. Failure modes — oracle manipulation, reentrancy, governance attacks.
5. Upgradability and ownership — proxy pattern? multisig? timelock?

Security questions

Be ready for:

• Reentrancy (classic + read-only).
• Oracle manipulation, flash-loan attacks.
• Signature replay, EIP-712 pitfalls.
• Front-running and MEV.
• Access control bugs (missing onlyOwner, wrong modifier).

Always think out loud — interviewers care about your process, not just the answer.

For non-developers (PM, marketing, BD, community)

Expect to be tested on:

• Blockchain basics: wallets, gas, L1 vs L2, custodial vs non-custodial.
• Tokenomics literacy: emissions, supply schedules, incentive design.
• Crypto culture: who the major protocols are, why decentralization matters, recent industry events.
• Async work: how do you operate without a manager checking in daily?
• Ownership examples: tell a story where you shipped something end-to-end without being asked.

Culture fit — what they are really testing

• Are you self-directed? Crypto teams are small and remote — nobody will hand-hold you.
• Are you ego-free? DAOs run on transparent debate, not titles.
• Are you in it for the long term, or just chasing a token pump?
• Do you actually use Web3 products, or just talk about them?

Two days before the interview

• Re-read the company's docs / litepaper.
• Open the GitHub of the interviewer if it is public — understand what they care about.
• Prepare 3 sharp questions for them (roadmap, biggest current risk, how decisions get made).
• Set up your environment: working webcam, quiet room, water, charged laptop.

During the interview

• If you do not know, say so. Then say what you would do to find out.
• Tie every answer back to a concrete example.
• End with: "What would success in this role look like at 90 days and at 12 months?"