juncture

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes

Production-grade Rust concurrency: threads, atomics, async/await, lock-free data structures, memory ordering, ABA problem, executor design, NUMA, work-stealing, deadlock prevention. Use when: building high-concurrency systems, implementing lock-free algorithms, debugging race conditions, optimizing async runtimes, handling synchronization primitives, choosing channel types (mpsc/crossbeam/flume/tokio), working with DashMap/ArcSwap/parking_lot, or asking about thread patterns (scoped threads, ThreadLocal, park/unpark, affinity, priority).

ALWAYS invoke this skill BEFORE writing or modifying ANY Rust code (.rs files) even for simple Hello World programs. Enforces Microsoft-style Rust development discipline, zero-tolerance quality standards (zero errors, zero warnings), and requires consulting the appropriate guideline files before any coding activity. This skill is MANDATORY for all Rust development.

Implement hexagonal (ports and adapters) architecture in Rust with clean separation between business logic and external dependencies. Use when: (1) User explicitly asks for `hexagonal architecture`, `ports and adapters`, or `clean architecture` in Rust, (2) Building testable services requiring clear boundaries between domain and infrastructure, (3) Multi-team projects (3+ developers) where coordination needs clear contracts, (4) Projects with expected lifetime 12+ months, (5) Domain-driven design with bounded contexts requiring isolation, (6) Applications where requirements change frequently and adapters need swapping.