Nethermind 15-Minute Technical Interview: What Ethereum Intern Candidates Should Actually Expect

I had a Nethermind interview last year for a similar internship. The first tech screen was very straightforward. No coding, no puzzles — mostly checking whether you understand Ethereum basics clearly.

They asked me things like:

• “What happens when you call a contract function?”

• “Explain storage vs memory in simple terms.”

• “Why does SSTORE cost more gas than SLOAD?”

Nothing about zero-knowledge, nothing too deep. They just wanted to see if I really knew what I claimed.

What helped me was being able to explain one smart contract I had written — what it does, where state changes happen, and why. They actually care more about whether you've built something real than whether you’ve memorized definitions.

So my advice: revise the fundamentals, don’t overthink it, and keep your answers short and clear. That’s all they’re checking in the first 15 minutes.

I’ve interviewed a few interns for Ethereum-focused teams (not Nethermind specifically, but similar style). The 15-minute round is usually meant to check whether you actually understand the basics you claim on your CV.

Most of the questions are short and direct. Examples I’ve seen:

“What’s the difference between a full node and a validator?”

“If a transaction fails, what usually causes it?”

“What is stored in contract storage vs memory?”

“What happens when a function modifies state?”

They’re not looking for textbook definitions — they just want to see if you can explain things without mixing concepts.

Big mistakes I’ve noticed from candidates:

Talking about ZK or rollups when the question was about simple L1 execution

Giving long answers that never get to the point

Mixing up calldata/memory/storage

Using terms like MEV or gas refunds incorrectly

If you keep your explanations short and accurate, you’ll be fine. You don’t need deep research knowledge for this round; you just need a clean mental model of how Ethereum works at a basic level.

Really appreciate everyone sharing their experiences here. From what we see across the AOB community, early-stage interviews at teams like Nethermind often come down to how clearly a candidate understands Ethereum fundamentals, not how many advanced topics they’ve memorized.

Even in short rounds, hiring teams look for clean explanations of execution flow, storage behaviour, and transaction failures — exactly the kind of points members have highlighted above.

If you're preparing for similar roles, a few resources inside AOB can help:

• Our Smart Contract Interview Prep Hub covers common patterns interviewers test and how juniors should structure answers:

https://artofblockchain.club/discussion/smart-contract-interview-prep-hub

• The discussion on Hardhat or Foundry first is useful for beginners who want to understand practical tooling expectations:

https://artofblockchain.club/discussion/hardhat-or-foundry-first-what-actually-helps-in-your-first-smart-contract

• And if you're exploring broader career direction, this thread on Guidance for Web3 development careers gives a realistic roadmap many interns found helpful:

https://artofblockchain.club/discussion/guidance-on-next-steps-for-web3-development-career

Keep sharing your interview stories — they genuinely help the next batch of students prepare with more confidence and fewer unknowns.