Blockchain
Also written as Distributed Ledger
A shared, append-only ledger maintained across many independent computers instead of one central database, designed so no single party can quietly rewrite history.
Think of it like
A shared notebook photocopied to hundreds of people, so no one person can tear out a page and get away with it.
Junior or senior?
Hype has cooled sharply since 2021-2022, so the word alone says little.
Senior sounds like
Worked on a system where the specific properties — no central authority, tamper-evidence — actually mattered, not just 'used blockchain.'
Ask them
“What specifically needed a blockchain here, instead of an ordinary database with an audit log?”
Sounds like real experience
Names a concrete reason an ordinary database wouldn't work for that system — no trusted central party, need for public verifiability.
Probe further if
Can't explain why the project needed decentralization specifically, beyond using the word because it was trendy.