Web3 Architecture interview questions

Wallets, RPC nodes, and decentralized storage.

3 questions in Blockchain & Web3.

Blockchain and Web3 EngineeringA 18-minute read on how the topic fits together, before the questions.Blockchain and Web3 fundamentals60 short answers on one page, for revising rather than studying.

medium2

mediumConceptScenario

What happens between a user clicking confirm in a wallet and the transaction landing on chain?

A wallet transaction signing flow chooses nonce and fee fields, encodes the transaction, signs the hash locally with the private key and sends only the signed transaction to an RPC node for mempool broadcast. Use this wallets answer to show the decision, trade-off, and evidence rather than a memorised definition. It also connects transactions to the point an interviewer is testing.

5 minmid, senior

mediumConceptDesign

When is decentralised storage genuinely the right choice over a normal database?

Decentralized storage is the right choice when content-addressed bytes must be independently verifiable and durable beyond one operator. A database is better for mutable records, access control, deletion, secondary indexes and low-latency queries.

5 minmid, senior, staff

hard1

hardDesignScenario

Your dApp backend reads and writes chain state through a hosted RPC provider. How do you make that dependency reliable?

dApp RPC node reliability means treating blockchain nodes as rate-limited, sometimes lagging read replicas rather than perfect infrastructure. Production backends need retries, confirmation depth, bounded log queries, nonce coordination and their own indexed reads.

6 minsenior, staff, lead