Flamegraphs

Valgrind profiler skill for memory error detection and cache profiling. Use when running Memcheck to find heap corruption, use-after-free, memory leaks, or uninitialised reads; or Cachegrind/Callgrind for cache simulation and function-level profiling. Activates on queries about valgrind, memcheck, heap leaks, use-after-free without sanitizers, cachegrind, callgrind, KCachegrind, or massif memory profiling.

Playwright browser automation API, web scraping, and tooling. Covers locator strategies, assertions, API testing, stealth mode, anti-bot bypass, authenticated sessions, screenshots/PDFs, Docker deployment, configuration, debugging, and MCP integration with AI agents. Prevents documented errors including CI timeout hangs, extension testing failures, and navigation issues. Use when automating browsers, scraping protected sites, bypassing bot detection, generating screenshots/PDFs, configuring Playwright Test, troubleshooting Playwright errors, or learning Playwright API patterns. For E2E test architecture, Page Object Models, CI sharding strategies, or test organization patterns, use the e2e-testing skill instead.

Runs real-user dogfooding sessions through the product's public interfaces: a persona walks a journey in the browser, takes a thematic tour, probes edges, hunts paper cuts, and reports what a real user would experience. Reads its plan from the living QA docs tree (<qa-docs-path>, default docs/qa/). Use when validating a release candidate, branch diff, migration, or user-facing change against production-like behavior. For planning that tree — personas, journeys, charters, the bug registry — use qa-report; for CI gate runs, AI implementation audits, or integration/security/performance suites, use agent-output-audit.

Implement distributed tracing with Jaeger and Zipkin for tracking requests across microservices. Use when debugging distributed systems, tracking request flows, or analyzing service performance.

Browser automation with two integrations - Chrome DevTools MCP (always available, performance tracing) and Claude-in-Chrome extension (authenticated sessions, GIF recording). Use DevTools for testing/debugging, Claude-in-Chrome for authenticated workflows.

Run and configure oxlint — the high-performance JavaScript/TypeScript linter built on the Oxc compiler stack. Use this skill whenever working in a project that has oxlint installed (check for `oxlint` in package.json devDependencies or an `.oxlintrc.json` / `oxlint.config.ts` config file). This includes when you need to lint code after making changes, fix linting errors, configure oxlint rules/plugins, set up or modify `.oxlintrc.json`, or migrate from ESLint.