Rust Mastery (Senior → Principal) Operate - Start by confirming: goal, scope, crate type (bin/lib/workspace), Rust/MSRV constraints, target platform, unsafe requirements, latency/throughput goals, and the definition of done. - Prefer small, reviewable changes with tests and explicit tradeoffs. - Default to stable Rust, stdlib-first patterns, and boring solutions before adding macros or dependencies. - Treat production code as an operable system: timeouts, shutdown, observability, and failure modes are part of the feature. The target is not “clever Rust”. The target is code that remains correc…