iiinova — where your digital self keeps evolving

Cathal Mac Donnacha @cathalmacdonnacha.com · 05/03/2026

If you're still using Jest, you may find this article useful to help speed up your tests. cathalmacdonnacha.com/fixing-slow-... #frontend #jest #testing

cathalmacdonnacha.com

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Cathal Mac Donnacha @cathalmacdonnacha.com · 04/03/2026

claude --worktree is amazing 🤌

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Cathal Mac Donnacha @cathalmacdonnacha.com · 05/09/2025

What are some ways AI tools have helped you with your frontend projects? Specifically the design side. #frontend #ai #claude #chatgpt #webdev

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Cathal Mac Donnacha @cathalmacdonnacha.com · 21/08/2025

I tend to use pagination when users need shareable links or to give a sense of how much data is left (e.g. “page 3 of 10 in blue t-shirts”). Use virtual scroll for endless browsing (e.g. social feeds). 📑 Pagination = easy to share & measure. 📜 Virtual scroll = easy to scroll. #frontend #ux #webdev

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Cathal Mac Donnacha @cathalmacdonnacha.com · 27/07/2025

When diving into a new codebase I find that tests serve as the best documentation. #software #webdev #programming

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Cathal Mac Donnacha @cathalmacdonnacha.com · 17/07/2025

I guess ChatGPT is training itself on my blog now 😂 #blogging #chatgpt #software

Screenshot of referrers from a blog (http://cathalmacdonnacha.com/)

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Cathal Mac Donnacha @cathalmacdonnacha.com · 18/06/2025

TIL: Chrome Dev Tools has an accessibility view ♿️ #frontend #chrome #webdev

accessibility view in chrome dev tools elements tab

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Cathal Mac Donnacha @cathalmacdonnacha.com · 14/06/2025

This is a real level headed take on AI and the perceived notion that it's going to completely take over software engineering roles: youtu.be/mbEzhI3cmmo?...

youtu.be

The Truth About Software Development with Carl Brown | Better Offline

YouTube video by Better Offline

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Reposted by Cathal Mac Donnacha

React @react.dev · 22/04/2025

React Compiler RC is now available! We've added support for swc and are working towards a stable release react.dev/blog/2025/04...

react.dev

React Compiler RC – React

The library for web and native user interfaces

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Cathal Mac Donnacha @cathalmacdonnacha.com · 03/04/2025

Before I begin any refactoring, I always have a look at the tests first to make sure they're up to scratch. This way I can be fairly confident that I won't break anything in the process. Emphasis on "fairly". 😂 #software #programming #frontend

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Cathal Mac Donnacha @cathalmacdonnacha.com · 02/04/2025

"To persuade a few is better than to convince many." This has always been my approach when introducing any new tools or patterns to wider teams. #software #programming #frontend

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Cathal Mac Donnacha @cathalmacdonnacha.com · 02/04/2025

The first thing I do when I want to familiarize myself with a new area in a codebase is check out the tests. Tests are a great form of documentation. #frontend #software #programming

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Cathal Mac Donnacha @cathalmacdonnacha.com · 01/04/2025

🔥 Want to improve UX on your frontend? Don't make users think. Keep it simple, intuitive, and effortless. The best UX is invisible - it just works. #ux #frontend

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Cathal Mac Donnacha @cathalmacdonnacha.com · 31/03/2025

Even though it's been out for years now, I feel like using React Query as an async state manager is a highly underrated and underused feature. tkdodo.eu/blog/react-que… #reactjs #frontend

tkdodo.eu

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Cathal Mac Donnacha @cathalmacdonnacha.com · 30/03/2025

It's important to have a healthy mindset towards feedback or setbacks. View them as opportunities to improve yourself. Focus on being constructive and solutions-focused rather than emotions-driven. #software #programming

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Cathal Mac Donnacha @cathalmacdonnacha.com · 28/03/2025

Starting a "brag document" was one of the best things I did for my career. It saves you a ton of mental effort and scrambling when those performance reviews come around! www.youtube.com/watch?v=gbkv... #software #career

youtube.com

The Easy Way To Document Your Accomplishments

YouTube video by A Life Engineered

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Cathal Mac Donnacha @cathalmacdonnacha.com · 27/03/2025

Sometimes I break production on purpose just so our users can appreciate how nice our error page is. 😁 #software #frontend #WebDevelopment

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Cathal Mac Donnacha @cathalmacdonnacha.com · 26/03/2025

Why it's important to clean up feature flags 👇

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Cathal Mac Donnacha @cathalmacdonnacha.com · 26/03/2025

Why I don't like Snapshot Testing 👇 - Takes a lot of effort to understand if the failure is expected. - Hard to evaluate if you're even testing your component correctly (compared to specific assertions). - Often blindly updated without checking if it was a legitimate failure.

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Cathal Mac Donnacha @cathalmacdonnacha.com · 05/01/2025

"The Staff Engineer's Path" by @whereistanya.bsky.social is a great book for anyone new to technical leadership.

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Cathal Mac Donnacha @cathalmacdonnacha.com · 04/01/2025

There's no point looking back, because we're not going that way.

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Cathal Mac Donnacha @cathalmacdonnacha.com · 28/12/2024

❌ Avoid storing derived state like totals, filters, or counts in useState. ✅ Calculate derived values directly in render from the existing state or props. Simple, clean, and avoids bugs caused by syncing issues! Learn more here: react.dev/learn/you-mi...

Code example showing redundant state along with a better alternative where you simply derive state.

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Reposted by Cathal Mac Donnacha

Visual Studio Code @vscode.dev · 27/12/2024

Claude 3.5 Sonnet, directly in VS Code. Available to everyone today with GitHub Copilot Free. Learn more: aka.ms/copilot-free

A screenshot of Copilot Chat in VS Code focused on the model picker which shows Claude 3.5 Sonnet (Preview) and GPT 4o

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Cathal Mac Donnacha @cathalmacdonnacha.com · 23/12/2024

Introducing new tools or patterns? ✅ Focus on persuading a few key advocates rather than convincing absolutely everyone. A few believers can spark wider adoption far more effectively. #software #webdev #frontend

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Cathal Mac Donnacha @cathalmacdonnacha.com · 18/12/2024

🔥 For actions that require sign in, avoid having a user perform the same action twice. 1. User clicks the like button on a comment. 2. User is asked to sign in. 3. User signs in successfully. ✅ Result: Comment should be displayed again and liked. #ux #webdev #frontend

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Cathal Mac Donnacha @cathalmacdonnacha.com · 16/12/2024

✅ It's a good idea to set focus to the first input field when loading a page or popup modal. ❓Is there any reason you wouldn't want to? #ux #frontend

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Cathal Mac Donnacha @cathalmacdonnacha.com · 15/12/2024

💻 Being able to communicate technical information to a non-technical audience is such an underrated skill. ❓Have you had to do this in the past? #software

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Reposted by Cathal Mac Donnacha

Cory House @housecor.com · 04/12/2024

I’ve found the fewer environments a software team has the better. Every additional environment adds cost, management overhead, out of sync risk, and delays deployment. My ideal? Just two environments - Dev and prod. Merge to main auto deploys. Feature flag as needed. 🔥

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Cathal Mac Donnacha @cathalmacdonnacha.com · 10/12/2024

🎄Have some fun with your mock/test data. Instead of "TestUser1", "TestUser2", pick some characters from your favourite TV shows. Omar Little and Saul Goodman often make an appearance in my tests. 😁 #frontend #software #webdev

media.tenor.com

a close up of a man 's face in a dark room .

Alt: Omar Little agreeing with a statement, saying "oh indeed".

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Reposted by Cathal Mac Donnacha

James Arthur @thruflo.com · 03/12/2024

Next.js and Remix's focus on SSR has added cruft and complexity to the core React use case of building interactive apps. @tanstack.com is the antidote to this: an opinionated framework that actually helps you get stuff done rather than forcing you to optimise for someone else's e-commerce use case.

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Cathal Mac Donnacha @cathalmacdonnacha.com · 03/12/2024

How am I just now discovering "Design Mode" in Chrome DevTools? ⭐️ 💻 #ChromDevTools #frontend #webdev

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Cathal Mac Donnacha @cathalmacdonnacha.com · 28/11/2024

Using TanStack Query's 'Optimistic Updates' pattern is one of the best ways to improve the UX. 🚀 Just make sure it's the right fit: ✅ Great for scenarios with high success likelihood (e.g. likes, toggles). ❌ Avoid for critical, high-risk actions or long flows (e.g. payments, irreversible changes).

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Cathal Mac Donnacha @cathalmacdonnacha.com · 27/11/2024

Ever wondered when you should adopt a new CSS feature? Read this 👇

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Cathal Mac Donnacha @cathalmacdonnacha.com · 27/11/2024

Just updated all of my articles 🦋 😀

Reference to Twitter being replaced with BlueSky

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Cathal Mac Donnacha @cathalmacdonnacha.com · 27/11/2024

I'm surprised to see how often "data-testid" is still used. I find it much more beneficial to avoid implementation details like that, and to focus on testing user interactions and elements users can actually see on screen. #frontend #webdev #testing

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Cathal Mac Donnacha @cathalmacdonnacha.com · 24/11/2024

Having solid ESLint and Prettier rules is one of the best ways to avoid nitpicks during PRs and keep consistent patterns across your project. #webdev #frontend

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Cathal Mac Donnacha @cathalmacdonnacha.com · 23/11/2024

The #1 best state manager in 2024 is...the URL. 😁 It's simple, it's global, and can be accessed from anywhere. #webdev #frontend

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Cathal Mac Donnacha @cathalmacdonnacha.com · 23/11/2024

Typescript highlighted a really dumb mistake I made recently and I just thought to myself how many hours I could have potentially wasted trying to debug it.

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Cathal Mac Donnacha @cathalmacdonnacha.com · 23/11/2024

One thing I hear often is "how do we test our app in all languages/ translations?" ✅ Recommendation: Just test with the default language. It's a good idea to test that changing a language does actually apply translations, but outside of that I don't think it's worth the time investment. #webdev

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Cathal Mac Donnacha @cathalmacdonnacha.com · 22/11/2024

Want to improve the UX on your frontend? Don't make users think. Keep interfaces simple, intuitive, and free of unnecessary complexity. Great UX is about making the user's journey effortless and enjoyable. #frontend #userexperience #uxdesign #webdev

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Cathal Mac Donnacha @cathalmacdonnacha.com · 21/11/2024

Complex tests are often a symptom of complex solutions. #software #programming #webdev

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Cathal Mac Donnacha @cathalmacdonnacha.com · 20/11/2024

Before I begin any refactoring in a new area, I always have a look at the tests first to make sure they're up to scratch. This way I can be fairly confident that I won't break anything in the process. Emphasis on "fairly". 😂 #software #programming #frontend #webdev

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Cathal Mac Donnacha @cathalmacdonnacha.com · 20/11/2024

This is the best feed 👇 Posts from people you follow without reposts and replies.

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Cathal Mac Donnacha @cathalmacdonnacha.com · 19/11/2024

🐛Every time you fix a bug, you should be writing a test for it so that it doesn't reoccur. #software #programming #webdev

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Cathal Mac Donnacha @cathalmacdonnacha.com · 18/11/2024

I prefer video tutorials over text-based ones. I think it's because I can follow and code along with someone, pause, rewind etc. How do you like to learn? #Software #programming #javascript #webdevelopment #frontend #react

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Cathal Mac Donnacha @cathalmacdonnacha.com · 18/11/2024

Ask 3 devs to define an end-to-end test and you'll get 5 different answers. #testing #software #programming

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Cathal Mac Donnacha @cathalmacdonnacha.com · 15/11/2024

🚀 Run this command if you ever want to delete all local git branches except for "main". #git #development #software #programming

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Cathal Mac Donnacha @cathalmacdonnacha.com · 15/11/2024

I'm looking forward to the day where we test in the browser by default without any trade-offs. JSDOM will be a distant memory.

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