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Mark Erikson
@acemarke.dev

Related to this: In 2023 I put together a POC "React + Redux perf analysis" tool in Replay DevTools. Could extract render + dispatch timings, selector calls + timings. Worked! but slow and expensive. Today I realized our analysis layer does 80% of that, and I could build the rest, efficiently!

Mark Erikson@acemarke.dev

My first year at Replay was modernizing our own DevTools FE codebase. Since then, I've spent all my time building out our sophisticated React analysis backend and digging into React's internals. I'd love to do conf talks and blog posts about this, but I feel like it's so niche there's no audience.

1 repost7 likes

Mark Erikson
@acemarke.dev

So I'm going to pick that up tomorrow and see if I can reimplement the perf timing and processing logic to extract the same data. Should then be able to expose that via the new Replay MCP, too! Here's my old prototype PR: github.com/replayio/dev... and example dispatch + selector perf data

Mark Erikson
@acemarke.dev

We've had multiple people ask the Redux team for better ways to measure perf from Redux dispatches, and there still isn't a good way to get a full picture of where the time was spent other than tracing call graphs and flame charts. I wanted to build that with Replay, and now I think I can!

Mark Erikson
@acemarke.dev

update: already have the first POC of the React+Redux dispatch+render perf timing working! lot more data wrangling to do, but just pulling out these values proves the pipeline works! on top of that, the new Replay MCP is actually helping me investigate behavior! genuinely incredible results!

Dennis Cual
@denniscual.bsky.social

Is the process of getting this information expensive? Does it run in same UI thread? I also had this old POC using blippy to retrieve perf timing but theres huge overhead.