What candidates say the round looked like, summarised in our words, each linked to where it came from. Block hasn’t confirmed these details unless the source says “Official page”.
read the files, write code, run tests (at least half of 1 reports)
The reports
Onsite · August 2026
Own machine · Kotlin
Block’s Live AI Build round, separate from the CoderPad coding screen: download a Kotlin codebase and work with a coding agent. The candidate asked Claude Code for an overview of the codebase, switched to plan mode, pasted the task and asked where the issue might come from, then refined the plan. The interviewer pushed hard on correctness: what ‘handle it correctly’ meant in a prompt, and why a one-line change should be accepted. After much back and forth they had the agent rewrite the test plan for feature parity, and didn’t finish implementing. They found it far harder than expected.
AI: Your own AI tools that could read the files, write code, run tests · Task: Fix bugs · Source: Blind thread