Perttu Lähteenlahti

AI slop is easy to recognize after the fact.

Fewer people, better experience I wrote a recap of last year's App.js conference in Poland, and it started to feel weird not to write one this year as well, since this year was quite different on my part, and also really highlighted the new trends in React

If you're looking for the invoice generator, it is at the bottom of the article.

TL;DR Use Linking.canOpenURL() with the target app's URL scheme to check if another app is installed.

In my previous article I played with animating the browser tab title using document.title.

Few days ago I came across a tweet, which I've sadly haven't been able to find after, where someone showed animated titles in Chrome's tabs.

Every business website has a "Contact us" button.

If you've ever spent an afternoon clicking through App Store Connect to update metadata, upload a build, or — god forbid — localize your app listing into 15 languages, you know the pain.

This is an interactive article that gets updated throughout the year.

I track my flights using Flighty and look back at the data each year.

TL;DR If you want to check whether another iOS app is installed from your SwiftUI app, use UIApplication.shared.canOpenURL() with the target app's URL scheme.

What is @perttu/app-store-scraper I recently published @perttu/app-store-scraper, a TypeScript rebuild of the app-store-scraper by facundolaano (it's a really good package by the way).

Introduction Building a great Android app takes time, creativity, and persistence.

I've been building a small project that I've wanted on my own phone for a long time: Netli.fyi, a native iOS client for Netlify.

TL;DR If you're seeing flickering, layout shifts, or scroll position resets when using React Query with FlatList in React Native, it's usually caused by conditionally replacing the entire screen based on loading state.

So I’m also taking part in Shipaton this year.

Took a quick visit to Krakow to give a talk at App.js, right after spending two weeks in Japan.

Goodbye Domain-Driven Development, Hello Domain-Embodied Development Vibe coding—prompting AI to generate code snippets—is getting increasing attention, not just among developers but also among people with little or no prior coding experience.

When building things using Netlify Functions, there are times you need to access environment variables in your functions.

Comprehensive look at in-app purchases and how to add them to your React Native app This article is based on the talk I gave at the first React Native London conference in 2024.

TL;DR If you want to add in-app purchases to your React Native app, you need to understand the different types (consumables, non-consumables, subscriptions), set up products in App Store Connect and Google Play Console, and use a library like RevenueCat to

This is a work in progress article version of the talk I gave in Krakow at RTC.ON Conference 2024.

Introduction: Novels vs. movies — who gets the credit?

In a project I'm working on, we have a case where many of the queries ran using the autogenerated Apollo GraphQL hooks that depend on the userID.

I recently needed to style the Html content that was injected into an element using the dangerouslySetInnerHTML property.

A bit over a month ago, Slack rolled out a new updated UI.

TLDR: You can customize the Developer Menu in React Native with your custom actions.

There are a lot of things the world can't seem to agree on, and one of them is how to format dates.

How to Do Usability Evaluation Introduction As technology continues to advance and evolve, the pressure to innovate and create products and services that make users’ workflows easier and combine previously separate tasks increases.

Introduction Human behavior is driven by incomplete data and methods to turn that data into action and perception.

Four approaches to designing digital services that persuade your user to live a healthier life Changing your habits from unhealthy to healthy ones is hard.

JAMstack is an architecture for building fast, scalable, and more secure services and products on the web with interchangeable services and prerendering.

Introducing Netli.fyi I am excited to announce the release of Netli.fyi, a mobile app that allows you to manage your Netlify sites on the go.

Not really a fan of yearly reviews.

1.

Hello, world!

How to gather user data, validate it, and organize it.

Using Styled-components with React and React Native is great.

When developing with React Native and nesting FlatList or SectionList components inside a plain ScrollView, your debugger might display the following warning: React Native Error VirtualizedLists should never be nested inside plain ScrollViews with the same

In this article, we are going to look at how to draw a nice-looking analog clock face by using react-native, react-native-svg, and styled-components.

A few days ago, I accidentally stumbled upon Publish, a static site generator that uses Swift as the language for building websites.

Create what is essentially a Spotify for ASMR.

This is a transcript of a lightning talk I gave at React Day Berlin in 2019.

The word “deep tech” gets thrown around a lot these days.

Best Books About the Tech World Getting into the tech scene, the world of startups, investors, and technology; is challenging if you didn’t study engineering or business.

If you're developing React Native apps for iOS you're most likely familiar with this command: react-native run-ios In most cases that command opens up the iPhone X simulator.

Releasing to App Store Getting your mobile app published in the App Store is simple in theory but tedious in practice.

Simulating real-life decision-making with card games Decision-making is perhaps one of the most exciting capabilities of human cognition.

Remember 3D TVs?

The Accidental Billionaires: The Founding of Facebook, a Tale of Sex, Money, Genius, and Betrayal by @benmezrich ⭐️⭐️⭐️ Reads more like a fiction book, but is still a decent look at the founding of Facebook.