Code Room
Vibe codingHardvc-g090
Subject Ai prompt iterationLevel Senior–Staff~22 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

You ask an AI to make a Rust struct `Config` cloneable so you can share it across worker threads. It adds `#[derive(Clone)]`, then the borrow checker fights it over a `Box<dyn Fn>` field, so it sprinkles `.clone()` calls; then it suggests wrapping the whole thing in `Rc<RefCell<Config>>`. Now it won't compile across threads at all (`Rc` isn't `Send`). The model keeps reaching for single-threaded sharing primitives. How do you re-steer to correct, thread-safe sharing?

What a strong answer looks like

Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it — tests, edge cases, reading critically — and how you’d re-prompt or decompose to get it right.

Describe your solution

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.