🪦 Android Instant Apps 🪦 2016 - 2025 R.I.P.

There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies and the other way is to make it so complicated that there are no obvious deficiencies. – Tony Hoare

I’ve spent my entire career in startups. Why? • I build things, not just org charts. • I move at 10x speed, no alignment meetings required. • I’m a generalist, not a cog in a machine. • My impact > my title.

Interviewing engineers is like watching kids play with blocks: • Some struggle with Duplos. • Some follow the manual. • Some build castles from thin air.

Here are the slides for the "Navigating Dependency Injection with Metro" talk I just gave at DroidKaigi. Great conference and super well-organized. speakerdeck.com/zacsweers/na...

NADD - Naming Avoidance-Driven Development - for the win! Just refactored an API to avoid the impossible: naming things. Because if we can’t agree on a name, we’ll just make it disappear 😅.

Code consistency is the backbone of scalable tooling. As your codebase grows, inconsistency becomes technical debt that cripples automation, refactoring, and even AI-assisted workflows. Consistency enables tooling, and tooling enables scale. Ignore it at your peril.

This week in frontend engineering: • Wrote an iOS strings file parser • Reviewed a Liang-Barsky implementation • Built a URI matcher using a tree • Debated efficient geospatial collision detection Who said frontend is about tweaking padding and building UI like Lego blocks?

Nouvelle saison ? Nouveau site ! Nous sommes ravis de vous présenter le tout nouveau site du Paris Android User Group ! ▶︎ paug.fr Un grand merci à toutes celles et ceux qui font vivre le PAUG et rendez-vous sur le site pour découvrir ce qui vous attend en 2025–2026

Flat surfaces are boring. Textures, when used thoughtfully, can transform user experience. We added subtle Perlin noise to our map tiles. Why? It helps users "anchor their eyes" to something tangible, reducing disorientation when zooming in/out. Small details, big impact. 🧵👇

OMG, I can finally review PRs without having to manually download images to view them in the finder 💥 github.blog/changelog/20...

Is anybody working on function-based DI framework? Most (all?) frameworks are class-based and don't fit well with Compose (function-based). …and yes I know about compositionLocalOf. But it's not checked at compile-time and is generally just for singletons.

Super excited today! I just completed the migration to a new cross-platform, type-safe, and modular deeplink framework. I’ve had this in mind for years but never implemented it. An interesting challenge was dealing with modularity and supporting multiple apps.

TIL about the 'super<Type>' expression in Kotlin. Reading a programming language grammar is always super insightful even though it's not useful everyday 😅. kotlinlang.org/docs/referen...

Investigated a broken internal-only feature this morning. Eventually found out it was actually not in the binary anymore. That's one of the problem of extreme modularity, it is (too?) easy to add/remove a feature from an app. With great power comes great responsibility 🕷️

Murphy’s Law is undefeated: your infrastructure will go down. But just because outages happen doesn’t mean your frontend should fall apart. 💥 Designing mesmerizing error states can ease user frustration … and buy engineers time to fix the issue.

Just discovered Internal App Sharing today. Completely missed it back then. Anyone using it? I'd love to have your feedbacks 😊 play.google.com/console/abou...

Bezier paths are pure magic ✨. This animation appears when your friends interact: smooth curves, vibrant gradient, particles dancing along the curve, sleek 3d effect. All made possible by the power of Bezier paths bringing UI to life.

When building a product, you sometimes need randomness that is repeatable (e.g. generating textures, shuffling lists). The solution is super simple: seed your random number generator with a fixed value.

Most think engineering growth is about scaling systems. That’s the easy part. Scaling culture and knowledge sharing is by far the biggest challenge.

James Lovell 1928 - 2025 Guided us through the stars.

The droidcon NYC 2025 videos were uploaded a few days ago. I finally took the time to upload the slides from the eulogy talk that @BQuenaudon and I gave about Instant Apps. Enjoy them until December 2025 ☠️… cyrilmottier.com/posts/2025/i...

I've been coding with bunch of different programming languages/environments over my career. The only one having true (i.e. compile-time) DI frameworks is Java/Kotlin. All other options I found are poor (i.e. runtime) DI / basic service locator. Did I miss something?

Building a suite of intercommunicating apps introduces unique challenges that very few engineers encounter: extreme modularization, cross-app data communication/persistence, inter-app navigation/deeplinks, and much more. It adds an entirely new & exciting dimension to mobile software engineering.

Obviously super aligned with everything that is discussed in here. Must read/watch 😎

Building this signature scratchmap recap animation was a lot of fun 🤩. It involved clustering scratched hexagons with H3, smoothly interpolating camera movements thanks to a centripetal Catmull-Rom spline, and adding some flair with animated WebP hexagon explosions.

Playing around with the UI for fun. Designing such micro-interactions and animations is a breeze thanks to Compose. P.S. If you didn't catch it, a full vinyl rotation takes exactly 1800ms. That's 33 RPM 🎶💿

Some colleagues question my high standards during interviews. I don't do it me. I do it for them. Ensuring new hires meet the bar helps retain a strong team.

Polishing transitions in your UI can truly elevate the user experience. They add significant value by providing feedback, emphasizing information hierarchy, guiding users, and engaging them with rewarding interactions.

The video of my "Build Scalable Mobile Projects" keynote @AndroidMakersFR is now live on YouTube! 🎥 Check it out here: www.youtube.com/watch?v=SmGi...

Modularization ensures scalable codebases but also comes with complexity. How do you detect unused modules in an Android Gradle-based project? I had to build an in-house tool for this but super curious how you do it. Same for unused code.

Properties of great internal tools: - Future-proof: maintainable, tested, strongly typed - User friendly: small/atomic actions, self-documented - Scalable: extensible, plugins - Performant: fast-feedback loop, incremental

We entirely re-engineered our annotation layout system to optimize readability and prevent text collisions. I can stop 😍 it. Another evidence skipping entirely Google Maps SDK for overlays/annotations rendering was a great move ✨ J2FtbyBuZWVkcyB5b3XigJk6IHdlJ3JlIGhpcmluZyE=

Stumbled upon some Röyksopp tracks recently. Haven't heard them for about 20 years. It is still mind blowing 🤯. I've listened to 'Sordid Affair (Notre Dame Remix)' at least 30 times in the past few days. 🎧 open.spotify.com/track/0tsTOO...

Mobile leaders, accelerate your mobile app development with rapid feedback loops. Embracing continuous delivery for internal builds is a good start. Every commit on main is downloadable. This boosts pace, quality, and simplifies bug bisecting.

Gave my 25-year-old hi-fi to my son – it didn’t work after 20 years of dust! While checking the issue, I found a gem. What I consider the CD of my life: Daft Punk's 'Discovery'. What a blast from the past!

When crafting a design system, teams often focus on colors, typography, shadows, UI components, and more. But there’s a crucial aspect many overlook: dimensions formatting (dates, times, speeds, lengths, etc.). By experience, it greatly reduces product and engineering friction.

Remember Kotlin Elvis operator and smart casts can simplify your code – no need to assign the result of the expression.

𝚓𝚘𝚒𝚗𝚃𝚘𝚂𝚝𝚛𝚒𝚗𝚐 is perfect to "stringify" an 𝙸𝚝𝚎𝚛𝚊𝚋𝚕𝚎. But it's way more powerful than you think. It's not just for simple separators! You can customize prefix, postfix, limit, truncate, and even transform. kotlinlang.org/api/core/kot...

Friends make everything better. Could you imagine life without them? 🤗 My best friend in programming is the compiler. I couldn't imagine coding without it! 💚

Amazed by what we’ve accomplished with Bump? That’s just the beginning! 🚀 @amoamoamo is expanding rapidly, and we’re looking for exceptional Android & iOS engineers to join our elite team in Paris. Together, we’ll create delightful and truly unique experiences.

This PR has been waiting for weeks and it's finally merged 🙌 Sources availability-driven development 😅

Instant Apps are not dead ☠️. In fact, they're trendy again! Join Benoit and me at @droidcon.bsky.social NYC to learn how to create the best instant experience possible.

Did you know Android Debug Bridge (adb) has a --bugreport option? It adds frame-related information overlays to video recordings. Super helpful for debugging animations, time to first meaningful frame, dropped frames, and more!

Speed dimensions are clear and readable, but let's face it—they can be a bit dull. That's why we've redesigned the friends pins on the map, introducing a dynamic speed & bearing-based tail. The effect is amplified using previous frames of the friends' avatars. #DetailsMatter.

It's surprising how many people think they're good at something without ever comparing themselves to the wider world. Go global, raise your game, and measure up against the best in your field. It's all about perspective and setting the right baseline.

My first advice to new team members: "Never take things at face value. Always ask why." Curiosity drives innovation and understanding.

After revamping my website, I've been asked multiple times to make the old content available. You can now get it here: cyrilmottier.com/legacy/ Perfect if you wanna read about Dart is going to shape the future of Android or how to build custom transitions with Fragments 😂

The end goal of the CI of a monorepo in one command: bazel build //...

Just went through all slides from my latest talk to switch from object opacity to color opacity. While generated PDF is okay, Speakerdeck completely hides objects with opacity. Deck should be much easier to understand now 😅 speakerdeck.com/cyrilmottier...