some teaser numbers. This is "total scripting time" from benchmark Chrome perf profiles. This branch is 20-30% faster in all but two scenarios, and one is an unrealistic edge case. Honestly looks very promising! Will try to put up a draft PR soon.

Just shipped the first versions of the new Replay MCP tools for analyzing Zustand stores and TanStack Query caches! We already had tools for React render insights and Redux actions+state. Now I'm adding more tools to give your agents insights into other libraries as well!

Heyyyy @danabra.mov ! I just created Replay recordings of your useDeferredValue bug . Fed them into a fresh agent session with general "issue report, go investigate" instructions... and Claude + Replay nailed the cause + solution in <10 minutes! Will write this up later, but this is great!

Just shipped new RecordingOverview and ReduxActions tools for Replay MCP! Overview surfaces renders, test failures, errors. Actions is Redux DevTools for agents. Ran against a real React 19 upgrade E2E failure recording, and an agent nailed the cause and fix in 30s! Exactly what we want to enable!

This seems pretty useful! Renders summary, renders list, render details, component aggregated details (instances, total time, which renders) . Pulling the MCP pieces together now! Hopefully will have this v0.1 live by end of the weekend :)

I've built this. It _works_ :) Still fleshing out details, and have to actually expose it via Replay MCP. But it _works_! - Complete list of React renders, with code + user cause - Every fiber that rendered, with reason (parent, direct state or store update, etc) and duration just gotta format :)

My Replay time-travel-based React+Redux perf reports experiments are coming together! Just nailed sourcemapped component + selector identities, and I've got accurate timing details on dispatches + renders from a Replay DevTools E2E recording! Early perf report example attached.

A week-ish later - it's working! Rebuilt my React+Redux dispatch+render perf POC on top of Replay's current infra. Currently extracting dispatch+render timings and selector calls . Just raw data atm, but now I can build meaningful visualizations / perf analysis with this! time travel's awesome!

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!

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

Thanks! Finally switched out the one I'd been using for years for a picture from NDC Oslo last year. Makes for an interesting angle, really.

I've kept hacking on my Immer perf rewrite branches during my last couple weeks of travel... and I think we have a winner! With small tweaks, rewritten cleanup, and array overrides in place, benchmarks show 20-90% faster (avg: 60%) vs current v10! github.com/immerjs/imme... should be PRed soon!

Seen _many_ complaints about "JUST RECOMMEND VITE", tone, Next/Vercel, and "frameworks" across the social media threads. Literally just got this Reddit reply pointing out how the docs don't actually help users with the "BYO Framework" approach.

This is totally a live picture of my research browser tabs right now:

Just looked at NPM download stats for ReactDOM, Next, Vite React, and CRA. CRA usage peaked 2 years ago, but still significant. Vite React is 2/3 of Next. For Oct: - ReactDOM: 108M - Next: 33M - Vite: 23.8M - CRA: 12M npm-stat.com/charts.html?... more reason to provide migration paths!

I updated this "Umbrella: Fix CRA" post with my suggestion for what an appropriate "Use Vite for SPAs and learning" recommendation should be in the React docs: github.com/facebook/cre... roughly: "if you're learning or just need client apps, use Vite. Here's the React / TanStack Router templates"

Gripe: the new TheRinger.com site design feels _awful_ and a huge step backwards. Here's the prior design a couple days ago. Simple, clean, organized, readable. Easy to find recent posts: web.archive.org/web/20241129... today? main fold is a giant timed carousel, rest is much harder to read

. @tkdodo.eu any reason why the `getNext/PrevPageParam` callbacks take positional args? Feels like this would be a good place to use object args and destructure, like if you only need `lastPageParam` (currently the third arg) here's what I'm looking at locally atm:

If you've looked at the Redux docs in the last week+, you may have noticed a banner for a "Redux.dev" course. The UI.dev folks did a fantastic React Query course ( query.gg ), so we're exploring doing one for Redux as well! Right now we're gauging interest - please sign up if you're interested!