Startup / AI-startup CTO who is also a top-tier individual contributor. Two modes: (1) greenfield — turn fuzzy business intent into a buildable design (brief.md, arch.md, specs/) through conversation; (2) brownfield — work hands-on inside an existing codebase: investigate, recommend, refactor, write features, debug, ship PRs, update ADRs and plan docs. Trigger when the user wants to build something new ('I want to build', 'help me design', '我想做', '帮我想想这个怎么做'), AND trigger when the user invokes /cto on an existing codebase for architecture work, migrations, refactors, debugging, or any senior-IC task they want CTO-level judgment and execution on. Do NOT trigger for trivial one-off coding questions where no architectural judgment is needed.
Golang benchmarking, profiling, and performance measurement. Use when writing, running, or comparing Go benchmarks, profiling hot paths with pprof, interpreting CPU/memory/trace profiles, analyzing results with benchstat, setting up CI benchmark regression detection, or investigating production performance with Prometheus runtime metrics. Also use when the developer needs deep analysis on a specific performance indicator - this skill provides the measurement methodology, while golang-performance provides the optimization patterns.
Golang CLI application development. Use when building, modifying, or reviewing a Go CLI tool — especially for command structure, flag handling, configuration layering, version embedding, exit codes, I/O patterns, signal handling, shell completion, argument validation, and CLI unit testing. Also triggers when code uses cobra, viper, or urfave/cli.
Golang code style, formatting and conventions. Use when writing Go code, reviewing style, configuring linters, writing comments, or establishing project standards.
Golang concurrency patterns. Use when writing or reviewing concurrent Go code involving goroutines, channels, select, locks, sync primitives, errgroup, singleflight, worker pools, or fan-out/fan-in pipelines. Also triggers when you detect goroutine leaks, race conditions, channel ownership issues, or need to choose between channels and mutexes.
Idiomatic context.Context usage in Golang — creation, propagation, cancellation, timeouts, deadlines, context values, and cross-service tracing. Apply when working with context.Context in any Go code.
Provides CI/CD pipeline configuration using GitHub Actions for Golang projects. Covers testing, linting, SAST, security scanning, code coverage, Dependabot, Renovate, GoReleaser, code review automation, and release pipelines. Use this whenever setting up CI for a Go project, configuring workflows, adding linters or security scanners, setting up Dependabot or Renovate, automating releases, or improving an existing CI pipeline. Also use when the user wants to add quality gates to their Go project.
Golang data structures — slices (internals, capacity growth, preallocation, slices package), maps (internals, hash buckets, maps package), arrays, container/list/heap/ring, strings.Builder vs bytes.Buffer, generic collections, pointers (unsafe.Pointer, weak.Pointer), and copy semantics. Use when choosing or optimizing Go data structures, implementing generic containers, using container/ packages, unsafe or weak pointers, or questioning slice/map internals.