SYSTEM Cited by 1 source

Perfetto

Perfetto is the Chromium project's open-source performance-trace visualisation and analysis UI at https://ui.perfetto.dev. It is the successor to the older chrome://tracing UI shipped with Chrome itself. Perfetto consumes traces in Chrome Trace Event Format (JSON) or in its own protobuf-encoded richer trace format.

Use in the corpus

• Turborepo's --profile flag emits Chrome Trace Event Format JSON that opens directly in Perfetto.
• Node.js --perf-basic-prof-only, Rust's tracing-chrome crate, Go's pprof-to-trace utility, and many other runtimes emit Perfetto-compatible trace JSON.

Agent-consumption limitation

In the 2026-04-21 Vercel Turborepo post, Anthony Shew observes that while Perfetto is "informative" for humans interactively exploring flame graphs, the underlying Chrome Trace Event JSON is structurally bad for agent consumption: function identifiers split across lines, irrelevant metadata interleaved with timing data, not grep-friendly. This motivated the Markdown companion profile pattern — emit both formats; Perfetto gets the JSON for human visualisation, the agent gets the Markdown for reasoning about hotspots.

Seen in

• sources/2026-04-21-vercel-making-turborepo-96-faster-with-agents-sandboxes-and-humans — canonicalises the JSON-format-for-UI / Markdown-format-for-agent split; Perfetto is the human-consumption substrate whose format's agent- hostility motivated the Markdown companion.

Related

• concepts/chrome-trace-event-format — the JSON format Perfetto consumes.
• concepts/flamegraph-profiling — the parent visualisation class.
• concepts/markdown-as-agent-friendly-format — the complement to Perfetto's JSON-for-UI shape.
• systems/turborepo — canonical Perfetto consumer in the corpus.