Author | Lightnews

Cyril Mottier @cyrilmottier.com · 6h

In most cases, Ints are not possible for us because we have sealed classes (aka enums with associated values).

Our alternative is interface + multiple implementations + multibinds. We trade compile-time exhaustivity and safety for scalability. You forget a @IntoSet a nobody will notice…

Cyril Mottier @cyrilmottier.com · 7h

bsky.app/profile/cyri...

Cyril Mottier @cyrilmottier.com · 9h

I actually wasn't talking about runtime performance. I was mostly referring to codebase scalability, modularization and build times.

Enums with 50+ variants all having different variants fields (which end up as sealed classes in Kotlin) pointing to symbols located in multiple modules in the code.

1

Cyril Mottier @cyrilmottier.com · 9h

I actually wasn't talking about runtime performance. I was mostly referring to codebase scalability, modularization and build times.

Enums with 50+ variants all having different variants fields (which end up as sealed classes in Kotlin) pointing to symbols located in multiple modules in the code.

1 2

Cyril Mottier @cyrilmottier.com · 10h

No I'm not talking about runtime performance. I'm talking about codebase scalability, modularization and build times.
Runtime performance wise, in our case, it's not a problem at all compared to everything else we do 😅

Cyril Mottier @cyrilmottier.com · 11h

Thanks to our savior: R8

Cyril Mottier @cyrilmottier.com · 12h

I love enums/sealed classes/union types. I really do. They give exhaustivity at compile time ❤️.
But they just don’t scale. I always end up making the painful choice of trading compile-time safety for scalability. It hurts, but it’s necessary.

4 3

Cyril Mottier @cyrilmottier.com · 1d

Killing the game

1 6

Cyril Mottier @cyrilmottier.com · 3d

Personal today's example: searching for the longest dependency chains - hence potential critical paths - in a build system-based directed acyclic graph and being 😲 by the result.

1 1

Cyril Mottier @cyrilmottier.com · 3d

They don’t teach you this enough in CS school: graph data structures and algorithms are everywhere. Maps, social networks, build systems, object graphs, page ranking, you name it.
Master them, and you’ll unlock superpowers in problem-solving. 🚀

1 6

Cyril Mottier @cyrilmottier.com · 3d

> During an investigation, your job is not to fix issues, it is to understand root causes.

@p-y.wtf says (and does) it all…

P-Y @p-y.wtf · 3d

I turned a leak investigation into a post on the Block eng blog to share a method that works well!

It's a bit long... I had to show how to encode code knowledge to automate leak investigations, and dig even deeper with YourKit Java Profiler.

engineering.block.xyz/blog/the-lea...

#AndroidDev

The LeakCanary Method

This blog post shares a method for root causing Android memory leaks

engineering.block.xyz

1 7

Cyril Mottier @cyrilmottier.com · 5d

It was the theme of the year. Carnival

2

Cyril Mottier @cyrilmottier.com · 5d

It is! Not the classical bread of course but it's bread! Italy was there too. Their craft is 🤌

2 1

Cyril Mottier @cyrilmottier.com · 5d

Coupe d'Europe de la boulangerie. Pièce artistique de l'équipe française.

1 1

Cyril Mottier @cyrilmottier.com · 7d

For example, here’s today’s snapshot from our project: only 4 modules are massive in LOC—and surprise, they all build in >15s on CI.
Now that we’ve measured, we can target fixes and optimize! Data drives action.

2

Cyril Mottier @cyrilmottier.com · 7d

A vital rule for scalability: every compilation unit must build in <15s (our threshold). Though build time ≠ LOC, tracking it reveals bloat, enforces discipline, and keeps your project fast as it scales. Speed is non-negotiable.

1 1

Cyril Mottier @cyrilmottier.com · 10d

Too late. I judge you. 😜

1

Cyril Mottier @cyrilmottier.com · 10d

I can't agree more. It is so true. A lot of work has been done because it was definitely the opposite back in the days.

4

Cyril Mottier @cyrilmottier.com · 10d

In a highly modularized codebase, typing full Gradle task names can be tedious. Gradle supports task name abbreviation: just type the shortest unique prefix. If ambiguous, Gradle suggests candidates.

⚠️ Use locally for speed, but keep codebase references explicit for readability!

2 3 5

Cyril Mottier @cyrilmottier.com · 11d

4️⃣Educate & guide
Teach through subtle, intuitive cues.

5️⃣Create immersive experiences
Pull users into the moment.

2

Cyril Mottier @cyrilmottier.com · 11d

5 ways motion elevates your product:

1️⃣ Emphasize information hierarchy
Guide attention effortlessly.

2️⃣ Add delight
Make interactions feel magical.

3️⃣ Provide feedback & status
Keep users informed in real time.

1 3

Cyril Mottier @cyrilmottier.com · 16d

Jeudi 16 octobre à 12h, je serai en direct avec Mathias de The Product Crew (TPC pour les intimes) pour parler engineering et produit ! Hâte d’échanger avec vous et de répondre à vos questions. À très vite !

3

Cyril Mottier @cyrilmottier.com · 17d

Thanks for the clarification. Our experience shows it's actually not a problem anymore thanks to large context windows and new rising features like context editing as the context grows.

1 1

Cyril Mottier @cyrilmottier.com · 17d

We built a custom animatable, collision-aware, collapsible annotation system on Google Maps. Huge UX improvement but we lost tilt support along the way.
We finally cracked the math and extended our projection calculations adding a whole new dimension to the map. Just gorgeous.

6

Cyril Mottier @cyrilmottier.com · 17d

Not sure I get your question. Can you elaborate please?

1

Cyril Mottier @cyrilmottier.com · 17d

In the age of AI agents, a monorepo isn’t just a dev setup. It’s a competitive edge. Everything in one place means agents can explore, analyze, and act across your entire codebase, seamlessly.

1 2