Tools, sandboxes and runtimes. What an agent can do to your system when it runs code.
3 traps, Sep 2026. Still running.
Set in interviews at Anthropic (1), Google (1) and Google DeepMind (1).
Each trap: the interviewer’s question, the answer most candidates give, and the mechanism that breaks it. The full answers are on Substack.
Senior AI Engineer interview at Google DeepMind
“You swap your agent’s backbone from DeepSeek to Qwen to cut costs. Same prompts, same tool schemas. Suddenly tool calls silently stop executing. No errors, no crashes. What broke?”
Agent Engineering #3
Sep 22, 2026
Senior AI Engineer interview at Anthropic
“You gave your coding agent 40 carefully written skills to make it smarter, and task success went DOWN. Each skill description is only a few lines, so it’s not a context-budget problem. What’s actually breaking, and how would you prove it?”
Agent Engineering #2
Sep 21, 2026
Senior AI Engineer interview at Google
“Your agent has 70 REST tools and needs 12 sequential calls to compare smartphone prices across 4 countries. Switching to code execution raises success rates and cuts turns. So why isn’t code execution the default for every agent?”
Agent Engineering #1
Sep 20, 2026