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Peter Kellner

@pkellner

Pluralsight author focusing on React. Silicon Valley Code Camp organizer.

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27.08.2023
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Latest posts by Peter Kellner @pkellner

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Denial of Service and Source Code Exposure in React Server Components – React The library for web and native user interfaces

I often check to see what’s new on the React blog, and it would be nice to see some positive news instead of always seeing this. react.dev/blog/2025/12.... @react.dev

21.02.2026 15:26 👍 0 🔁 0 💬 0 📌 0
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Understanding React's useEffectEvent: A Complete Guide to Solving Stale Closures | Peter Kellner's Blog React 19.2's useEffectEvent hook eliminates the useRef workaround pattern for accessing latest state in Effects. Learn when and how to use it.

peterkellner.net/2026/01/09/u...

27.01.2026 00:45 👍 1 🔁 0 💬 0 📌 0
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Understanding React's useEffectEvent: A Complete Guide to Solving Stale Closures | Peter Kellner's Blog React 19.2's useEffectEvent hook eliminates the useRef workaround pattern for accessing latest state in Effects. Learn when and how to use it.

peterkellner.net/2026/01/09/u...

26.01.2026 01:03 👍 0 🔁 0 💬 0 📌 0

Well, that was a long time ago. I’m assuming the source is still where it’s always been which is in the download tab at Pluralsight.

18.01.2026 15:46 👍 1 🔁 0 💬 0 📌 0
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Using AI to Create Secure MySQL Password Rotation Scripts (Without Exposing Secrets) | Peter Kellner's Blog How to leverage AI assistants to build password management scripts while keeping your actual credentials completely private.

Updating passwords to mysql use to be a hassle until AI helped writing all those crazy scripts. best practices is one user/password per catalog. That's a lot of users and passwords! peterkellner.net/2025/12/31/a...

31.12.2025 20:23 👍 1 🔁 0 💬 0 📌 0
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you can still teach math! I started volunteering in my local highschool Math III course. Then, ended up taking on a course teaching 5 kids HTML, CSS and JS (we build wack-a-mole). NO! the mole goes IN the hole!!! (most fun part of day)

30.11.2025 17:47 👍 3 🔁 0 💬 0 📌 0

The membership process sounds a little like fight club.

22.10.2025 04:23 👍 1 🔁 0 💬 1 📌 0

Learnings From Coding with AI (Claude Code): This may be my last in this series (if anyone is listening). At ReactConf, I learned a lot (including from @leerob.com) and have switched From CC to Cursor. So far, the honey moon is going great! I need a new name "Learnings From ??:" Suggestions?

09.10.2025 16:20 👍 0 🔁 0 💬 0 📌 0

Nice! Great follow-up. I loved (in a sic kind of way) watching you struggle with simple things. Makes me feel like you are one of us.

09.10.2025 15:49 👍 1 🔁 0 💬 0 📌 0
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a man riding a bike down a street with a drum that says gimbrinhas ALT: a man riding a bike down a street with a drum that says gimbrinhas

@caledhwa.bsky.social you don’t look like a fat biker.

08.10.2025 13:56 👍 1 🔁 0 💬 1 📌 0

They absolutely should have let you finish, you were just about to deliver the punch line when the hook came out. Absolutely everyone in that audience would have happily stayed for another 5 minutes. That's why we all came! At lunch, several other told me that too.

08.10.2025 12:30 👍 1 🔁 0 💬 0 📌 0

Learnings From Coding with AI (Claude Code): I wish Claude Code was like a junior programmer in that when you teach it something, it remembers the technique for the next time. for me, it's like groundhog day, everyday.

08.10.2025 12:28 👍 2 🔁 0 💬 1 📌 0
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Learnings From Coding with AI (Claude Code): It's hard to believe there isn't some thinking going on here. Claude admits its fallacies.

07.10.2025 12:54 👍 1 🔁 1 💬 0 📌 0
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Only in New York, at JFK checking in, told the lady that my extra bike charge of $200 was nothing compared to the hotel for 450 last night. She said they should’ve bathed you for that much.

02.10.2025 10:55 👍 0 🔁 0 💬 0 📌 0

Learnings From Coding with AI (Claude Code): "Are you again adding useEffect when you should be calculating values form existing state, and understanding that state changes cause un-needed re-renders?". I'm so tired of saying this even though I have it clearly in my `claude.md` file.

28.09.2025 06:39 👍 1 🔁 1 💬 0 📌 0

Learnings From Coding with AI (Claude Code): When seeing context available at the bottom get low (like less then 5%), don't think about asking another question that might lead to "compacting...". Nothing ever comes out right for me after compacting. Do: /clear and restart conversation fresh.

27.09.2025 05:11 👍 0 🔁 0 💬 0 📌 0

Glad to see @tannerlinsley.com speaking! He's got a great real world perspective on the stuff he builds and adds a lot of value to our community.

27.09.2025 04:52 👍 1 🔁 0 💬 0 📌 0

Learnings From Coding with AI (Claude Code): I use to have more faith and even wanted a more headless experience with CC. Now, I've learned to watch it carefully and constantly type feedback as it does stuff. It apprecaites it :). CC: "now I understand the problem better, thanks for clarifying"

27.09.2025 04:48 👍 0 🔁 0 💬 0 📌 0

They are all staying very quiet

24.09.2025 19:42 👍 0 🔁 0 💬 1 📌 0

Learnings From Coding with AI (Claude Code): Not exactly a learning, but I wish Claude Code would learn from what I tell it. I makes the same mistakes over and over and over. Maybe @anthropic.com will someday, or someone else like @openai.com will.

24.09.2025 07:12 👍 2 🔁 0 💬 0 📌 0

Learnings From Coding with AI (Claude Code): "I see the issue! The isPaused prop only affects the DISPLAY - it doesn't actually stop the status checking". Always be extra extra clear when asking for updates. It just changed the button labels, not the functioning

24.09.2025 04:25 👍 1 🔁 0 💬 0 📌 0

That's a great suggestion! Thanks. It only recently occurred to me that all the "fixing" CC does before giving me the code is based on "it compiles". That kind of use to be a joke (and now the joke is on me)

20.09.2025 14:03 👍 0 🔁 0 💬 0 📌 0

Learnings From Coding with AI (Claude Code): Does it bother anyone else that CC iterates until it gets a successful compile and then declare it working? (that is, when node and typescript at least). I have to explicitly tell it to write tests which it often doesn't like to do.

20.09.2025 13:10 👍 0 🔁 0 💬 1 📌 0

I really want engagement to encourage discussion.

19.09.2025 07:30 👍 0 🔁 0 💬 0 📌 0

Yeah, good to know its not 100% me. I don't want to go to x, as I already go there too much. Any other suggestions where AI folks hang out?

19.09.2025 07:29 👍 0 🔁 0 💬 0 📌 0

Hey follow claude code travellers @anthropic.com, I've been posting "Learnings From Claude Code" for quite a while and not getting much/any traction. Any suggestions?

19.09.2025 07:24 👍 0 🔁 0 💬 1 📌 0

Learnings From Coding with AI (Claude Code): "The problem is in phase1-metadata-discovery.ts. Someone added a misguided "optimization" that blindly adds all child folder
metadata paths". Guess who "someone" was

19.09.2025 05:52 👍 1 🔁 0 💬 0 📌 0

Learnings From Coding with AI (Claude Code): When I find a code problem, I make CC build a test to demonstrate the problem and the failure. Then I make it fix that test to work. Then iterate on this: " Hmm, my test isn't reproducing the exact bug."

18.09.2025 05:22 👍 0 🔁 0 💬 0 📌 0

Thank you!

09.09.2025 19:29 👍 0 🔁 0 💬 0 📌 0

Learnings From Coding with AI (Claude Code): Claude Code does not think like us. I find it often undoes what I asked it to do in a previous context if my next request touches that. It doesn't remember why it did, it just does again as if it were a robot (wait, it is a robot)

08.09.2025 03:02 👍 0 🔁 0 💬 0 📌 0