Technical Screen

Mempool Block-Mining Problem in the First Technical Round

CoinbaseSoftware Engineer · Technical Screen · May 2026

A former coworker referred me, and HR contacted me about three weeks later. The first round was technical. Part one Cryptocurrency "mining" is the operation where a "miner" places "transactions" in a candidate "block". Each block has a fixed size B = 100. At any point in time there is a set of transactions available for mining in an unordered array called the mempool. A transaction can be describ…

Shared by a candidate · reported May 2026. Interview formats change; use it as a guide, not a script.