Sign in

Mark Erikson

@acemarke.dev
7.9K followers 502 following 1.4K posts

Redux maintainer, building time-travel devtools at Replay.io. I blog about React, Redux, and TS at blog.isquaredsoftware.com . Answering questions anywhere there's a textbox on the internet, and otherwise out on the golf course!

PostsRepliesMedia
Reposted by Mark Erikson
Jovi 🐨 @jovidecroock.com · 8h
Preact 11 is out 🎉 We’ve been hard at work at making our diffing use modern features like moveBefore , leveraging ESM for tree-shaking Preact Compat and ensuring you have a great experience with resumed hydration.
57918
Mark Erikson @acemarke.dev · 28/09/2026
also I have been accumulating more Opinions on how I feel about using AI for development, and after recent conf conversations I'm pretty sure I have enough material to put together a third post in that series. Not concrete yet, but thoughts are bubbling around in my head :)
051
Mark Erikson @acemarke.dev · 28/09/2026
sorta self-indulgent question, but: would there be any interest in me writing up a career history retrospective blog series? Not sure I have a particular goal in mind, but might be neat to write at some point. (obviously I can post whatever I want, just curious if it's worth prioritizing)
4100
Mark Erikson @acemarke.dev · 28/09/2026
This helps clear the way for the next wave of Redux library major versions that I'm planning out. Quick preview: RTK3 API tweaks to improve types and enable new features, a couple breaking changes for DX, and dropping CJS to go ESM-only in all our packages. Details soon!
010
Mark Erikson @acemarke.dev · 28/09/2026
For the prior background and PR links, see: github.com/reduxjs/redu... The merge included deduplicating content and links from the separate sites. I also did a massive cleanup pass on the core docs, modernizing all pages that had obsolete legacy info.
github.com
[Docs] Considerations for merging all our docs into a unified docs site · Issue #4789 · reduxjs/redux
Background Copy-pasting my comment from reduxjs/redux-toolkit#2637 (comment) (and also similar thoughts in https://www.reddit.com/r/reduxjs/comments/1e4r3ts/the_worst_documentation_ever/ ): For ver...
110
Mark Erikson @acemarke.dev · 28/09/2026
This had been frequently requested over the years. My standard answer is "we'd have to merge our repos into a mono-repo and that'd be too hard". Last year I figured out a viable approach (clone all repos in CI), and over the last couple weeks was able to push that through to completion.
110
Mark Erikson @acemarke.dev · 28/09/2026
Excited to announce that: **We now have a single combined docs site for all the Redux libraries!** so, all of our docs for Redux core + usage, Redux Toolkit, React Redux, and Reselect now live together in: redux.js.org hopefully this makes it easier to navigate our docs!
redux.js.org
Redux - A JS library for predictable and maintainable global state management | Redux
A JS library for predictable and maintainable global state management
1394
Reposted by Mark Erikson
Jovi 🐨 @jovidecroock.com · 26/09/2026
Releasing Preact 11 with better hydration, moveBefore support and some reshuffling may sound like a boring release but to me it feels like completing something I've thought about for a while, I want to thank everyone for supporting Preact and enabling my journey
1131
Mark Erikson @acemarke.dev · 26/09/2026
Congrats! and yes, some similar feelings on my side working on Redux: bsky.app/profile/acem...
140
Reposted by Mark Erikson
Dominik 🔮 @tkdodo.eu · 26/09/2026
It's @farisaziz.com time in Alicante 🙌
Faris on stage, slide saying "Building Resilient UIs with React"
0181
Reposted by Mark Erikson
Ankita Kulkarni @kulkarniankita.com · 26/09/2026
@tkdodo.eu kicking us off at @reactalicante.es 🚀
0111
Mark Erikson @acemarke.dev · 25/09/2026
fun story: _I_ learned TS conditional programming in 2019 when Lenz coached me through writing a PR to RTK and I finally realized "OH THAT'S JUST A TERNARY, IN THE TYPE SYSTEM!" blog.isquaredsoftware.com/2019/11/blog...
blog.isquaredsoftware.com
Blogged Answers: Learning and Using TypeScript as an App Dev and a Library Maintainer
Thoughts on my experiences learning and using TypeScript, from different perspectives
000
Mark Erikson @acemarke.dev · 25/09/2026
.... uh HI I RECOGNIZE THAT ARCANE TYPESCRIPT INCANTATION THAT'S FROM OUR LIBRARY REDUX TOOLKIT! :) /cc @phry.dev
blog.isquaredsoftware.com
Blogged Answers: Learning and Using TypeScript as an App Dev and a Library Maintainer
Thoughts on my experiences learning and using TypeScript, from different perspectives
100
Reposted by Mark Erikson
Kevin Powell @kevinpowell.co · 25/09/2026
CSS keeps getting better and better, but the problem with hearing about amazing new features is that we're stuck not being able to use them for a few years because of browser support. So, this week I looked at a bunch of well-supported CSS features that I still see people turn to JS for.
youtu.be
Use these CSS features instead of JavaScript
YouTube video by Kevin Powell
5595
Reposted by Mark Erikson
eskimojo @eskimojo.bsky.social · 25/09/2026
Now that Schema Benchmarks has been officially released for 7 months, I thought it'd be useful to look at how it's improved over that time, and how it's helped the ecosystem! schemabenchmarks.dev/blog/7-month...
schemabenchmarks.dev
7 Month Update | Schema Benchmarks
An examination of how Schema Benchmarks has evolved (and caused other libraries to evolve) over the past 7 months.
011
Mark Erikson @acemarke.dev · 25/09/2026
lots of mourning, yeah :(
020
Mark Erikson @acemarke.dev · 25/09/2026
drat I think I just drafted a third post in my "Thoughts on AI" blog series with that thread :)
160
Reposted by Mark Erikson
François Best @francoisbest.com · 25/09/2026
Haven't been active much here, sorry, AI-in-OSS burnout is real. How do you care when nobody else does? When nobody engages? When all the human connection is gone? When all you read is AI slop? I want to go back to coding for fun. Because whatever this is, it's very much _not_ fun.
1611111
Mark Erikson @acemarke.dev · 25/09/2026
so I guess I'm just saying "I've built up a list of things to work on over the last few years, and I'm going to keep chewing through that list as much as I can, and if anyone uses my libs they'll benefit"
180
Mark Erikson @acemarke.dev · 25/09/2026
OSS is absolutely in a weird place right now. Too much AI spam and slop, communities shrinking, etc. I also feel pretty disconnected from my own lib bc I don't even write FE code for my job, so I don't have that experience to shape my maintenance efforts. Kinda doing it blind in that sense.
160
Mark Erikson @acemarke.dev · 25/09/2026
Maybe I'm doing work into a void at this point and no one will notice. Also in a weird place because of everyone caring less about frameworks + Redux being "obsolete". But I still put the responsibility on myself and plan to push my tools forward as long as I can.
150
Mark Erikson @acemarke.dev · 25/09/2026
Honestly I've ended up in a place where I now feel pretty empowered to actually crank through a lot of features, cleanup, and rewrites that I hadn't had the time for over the last years :) Been doing docs rewrites and restructuring, new features, and working towards major prototypes.
170
Reposted by Mark Erikson
Faris Aziz @farisaziz.com · 25/09/2026
@danieljcafonso.bsky.social opening the day at @reactalicante.es
272
Mark Erikson @acemarke.dev · 24/09/2026
I touched on this in my own "coming to terms with AI" post earlier this year: blog.isquaredsoftware.com/2026/05/ai-t... even if the frontier labs all collapsed overnight, LLM tech wouldn't vanish. Open models exist, local hosting exists. and there's a massive industry beyond that.
blog.isquaredsoftware.com
My Thoughts on AI, Part 1: Fears, Opinions, and Mental Journey
My own personal thoughts and opinions on AI effects and usage, and how those have evolved over time
011
Mark Erikson @acemarke.dev · 24/09/2026
See the alpha.0 release notes for details on `useSignalSelector`: bsky.app/profile/acem...
000
Mark Erikson @acemarke.dev · 24/09/2026
Just published React-Redux v9.4.0-alpha.1 . This fixes `useSignalSelector` proxy tracking behavior when reusing memoized selectors across components, and updates docs on tradeoffs and edge cases github.com/reduxjs/reac... See the alpha.0 release notes for background on `useSignalSelector`
github.com
Release v9.4.0-alpha.1 · reduxjs/react-redux
This alpha release fixes a bug where useSignalSelector stopped updating when a memoized Reselect selector was shared between components or called with the same state twice, changes how array method...
130
Reposted by Mark Erikson
Faris Aziz @farisaziz.com · 23/09/2026
Yay, Alicante! @nst.blue @acemarke.dev @tkdodo.eu @mkrl.xyz
6313
Reposted by Mark Erikson
patak @patak.cat · 22/09/2026
I'm so grateful for the communities we're part of, both offline and online. Such wonderful folks all around us.
2812
Mark Erikson @acemarke.dev · 22/09/2026
`useSignalSelector` provides noticeable perf improvements across a range of benchmark scenarios, with a tradeoff of larger bundle size. It can also be used as a drop-in replacement for `useSelector` if desired. We've tested it thoroughly, and now want to hear how it works in real-world apps!
020
Mark Erikson @acemarke.dev · 22/09/2026
`useSignalSelector` optimizes dispatch+subscription performance in large apps. It tracks selector state access via a proxy and skips re-running subscribers when state fields haven't changed. Most apps should use standard `useSelector` - we've designed `useSignalSelector` to help with larger apps.
120
Mark Erikson @acemarke.dev · 22/09/2026
Just published React-Redux v9.4.0-alpha.0 ! This release adds the new `useSignalSelector` hook, which optimizes selector subscriptions via proxy tracking. It's been heavily tested, and we're now looking for feedback on how it works in real-world codebases! github.com/reduxjs/reac...
github.com
Release v9.4.0-alpha.0 · reduxjs/react-redux
This alpha release adds an opt-in useSignalSelector hook and SignalProvider component that only re-run selectors whose state dependencies actually changed, plus a react-redux/signals entry point fo...
170
Reposted by Mark Erikson
danielroe @danielroe.dev · 22/09/2026
you can read what I've written about why this is EXACTLY my role in leading nuxt > I would be remiss not to speak about values. > Values shape the direction of projects and people [and] the culture of open source communities […] both in where we end up + what the journey there is like.
roe.dev
Diversity, equity and inclusion
I'm in favour of diversity, equity and inclusion in open source communities, and here's why I think it matters.
3506
Mark Erikson @acemarke.dev · 22/09/2026
party will be located SW of Africa!
010
Mark Erikson @acemarke.dev · 20/09/2026
Actual request: has _anyone_ come up with a userscript or extension or alternate version of the Github Notifications tab that lets you actually filter out PR/issue entries by some criteria, like a text match or whether the last comment is from a bot? I live in that tab, but it's _painful_ :(
130
Mark Erikson @acemarke.dev · 20/09/2026
This looks like the direction we'd want to go. Still a lot we'd have to do: set up infra in the other repos to still get PR previews; set up redirects; do a massive rethink of our docs content and organization to dedupe and make it easier to follow; and actually ship it. But, big steps forward!
001
Mark Erikson @acemarke.dev · 20/09/2026
The impl clones the other repos into core in CI, and runs a multi-instance Docusaurus site build. This seems to work surprisingly well! All four sites are there, with their setup quirks, and very little customization needed: deploy-preview-4950--redux-docs.netlify.app
deploy-preview-4950--redux-docs.netlify.app
Redux - A JS library for predictable and maintainable global state management | Redux
A JS library for predictable and maintainable global state management
120
Mark Erikson @acemarke.dev · 20/09/2026
We've had many complaints over the years that the 4 separate Redux docs sites (core, RTK, R-R, Reselect) makes it confusing to navigate. I'd always said "we aren't doing a monorepo, so no combined docs". Well, I now have a working prototype of a combined docs site :) github.com/reduxjs/redu...
github.com
[DRAFT] Full prototype of a combined docs site by markerikson · Pull Request #4950 · reduxjs/redux
Supersedes #4792 Fixes #4789 (eventually) In #4792 , I experimented with a Git-based approach (using submodules, I think) to pulling in the other repos so we could use Docusaurus's multi-instan...
160
Mark Erikson @acemarke.dev · 18/09/2026
Yep! I was a bit surprised , usually I see posts _before_ they end up in newsletters :) but that's why I subscribe to them. I'm on conf travel again this next week, but let's find time after I'm back! Also, would love any feedback on github.com/reduxjs/reac... if you have time / interest!
github.com
[DRAFT] Add prototype signals+path-tracking implementation by markerikson · Pull Request #2318 · reduxjs/react-redux
This PR: Adds a pair of signals-based alternative Provider/selector implementations, SignalProvider and useSignalSelector, designed to optimize the performance of subscriber notifications and sele...
010
Mark Erikson @acemarke.dev · 18/09/2026
@walterra.dev I think you wrote this migration post? Would love to chat sometime to hear about your experience doing the migration and any lessons learned from it! I'm actually in the early planning stages for RTK3 and would appreciate real-world feedback on usage!
110
Mark Erikson @acemarke.dev · 18/09/2026
Great writeup from the ElasticSearch / Kibana team on how they did a large migration to Redux Toolkit v2 ! Really appreciate seeing the examples of a huge real-world codebase and the challenges involved, and that RTK's features were helpful here! www.elastic.co/search-labs/...
elastic.co
Redux Toolkit v2 migration: 1,100 files, no code freeze
How Kibana runs Redux Toolkit v1 and v2 side by side: npm aliases, webpack externals, yarn resolutions, and an ESLint rule that stops the two mixing.
170
Mark Erikson @acemarke.dev · 16/09/2026
that's always been my biggest annoyance with package listings on NPM (and now seemingly NPMX). Yes, download size and install size in node_modules matter... but those are often radically different than bundle size shipped to the browser, and that doesn't get surfaced very well.
020
Mark Erikson @acemarke.dev · 16/09/2026
Normalizr was explicitly unmaintained by its owner a few years ago, and the announcement said "feel free to fork this"
110
Mark Erikson @acemarke.dev · 15/09/2026
Doesn't look like it gets that much usage overall: npmx.dev/package-stat...
npmx.dev
Stats - normalizr - npmx
Stats for normalizr
000
Mark Erikson @acemarke.dev · 15/09/2026
Anyone out there still using Normalizr? It's been unmaintained for a few years, but a user is asking about reviving and maintaining a fork if there's interest: github.com/reduxjs/redu...
github.com
Would you use an actively maintained, compatibility-first successor to Normalizr? · reduxjs redux-toolkit · Discussion #5442
Hi everyone, I've been looking at the current state of Normalizr and the discussion around its future, and I'd be willing to take responsibility for building and maintaining a modern, compatibility...
320
Reposted by Mark Erikson
Faris Aziz @farisaziz.com · 14/09/2026
@tkdodo.eu 🥹. This thread was just jaw dropping. Thank you for taking the time to summarize the experience and you have no idea how much this means to the whole team. I have no words except for saying it was a wholehearted pleasure to open our city to you and share our community love 💛
081
Reposted by Mark Erikson
Faris Aziz @farisaziz.com · 14/09/2026
You all made it so special that we could not refuse the demand to bring it back! Stay tuned!
0101
Reposted by Mark Erikson
Dominik 🔮 @tkdodo.eu · 14/09/2026
Anyone else feeling kinda sad because @zurichjs.com is over but also super nostalgic because it was so lovely? 🥹🥰
6201
Mark Erikson @acemarke.dev · 14/09/2026
Not sure if you saw my related post, but in case not: _right_ after we talked in Miami I wrote a post on my own personal emotional journey going from hating AI to using it. I talked a lot about the "craft" aspect in there and came to the same conclusions: blog.isquaredsoftware.com/2026/05/ai-t...
blog.isquaredsoftware.com
My Thoughts on AI, Part 1: Fears, Opinions, and Mental Journey
My own personal thoughts and opinions on AI effects and usage, and how those have evolved over time
1100
Mark Erikson @acemarke.dev · 13/09/2026
Wouldn't have known you were a fan of you hadn't made some noise about it!
020
Reposted by Mark Erikson
Dominik 🔮 @tkdodo.eu · 13/09/2026
@zurichjs.com was so special I can't put it in words. You have to experience the care, love and detail the organizers put into it first hand, hopefully in the NEXT edition of it 🔥
Group photo of the ZurichJs organizers, volunteers and speakers on stage
2231