Zac Sweers

zacsweers.devSponsoring MetroMetro is the proudest work of my career. Ever since starting it on vacation in November 2024, building it has been an incredible journey and the community reception has been nothing short of wonderful...

29 Jan

👋 Hi everyone, I’m enabling GitHub Sponsors for Metro If Metro has improved your developer experience or saved your team's build times, I’d appreciate the support! Full pitch and ROI napkin math here: www.zacsweers.dev/sponsoring-m...

github.comRelease 1.5.0 · ZacSweers/metroNew [metrox-viewmodel-compose] Add support for linuxX64. [FIR] Add the diagnostic-level compiler option to change the severity of Metro diagnostics reported in FIR. It works like kotlinc's -Xwarni...

Metro 1.5.0's a huge release with up to 50% smaller generated graphs, IC improvements, and a new hidden contributions Gradle task. github.com/ZacSweers/me...

12 Aug

MadeByGoogle events continue to be weird influencer-washing and, at best, disingenuous

31 July

Is founders not using caps the new faking a vocal fry?

github.comRelease 1.4.0 · ZacSweers/metroNew Experimental support for suspend providers This release introduces experimental support for suspend providers. This is disabled by default and can be enabled by the metro.enableSuspendProviders...

30 July

Metro 1.4.0 brings suspend providers! ⚡ github.com/ZacSweers/me...

github.comProposal: Suspending providers · ZacSweers metro · Discussion #1941The Proposal Here's the idea: A "suspending provider" may be written as follows: @Provides suspend fun provideDeviceId(@Io ioDispatcher: CoroutineContext): String = withContext(ioDispatcher) { gene...

30 July

Suspend providers have been in the works for months, h/t @jingibus.bsky.social for writing up the original proposal. There's more work here but pretty happy with how this core runtime has shaped up! Please give feedback/ideas/etc on the original MEEP: github.com/ZacSweers/me...

Zac Sweers reposted

Nick Ames

@nickames82.bsky.social

29 July

Enough statements, enough words, enough "careful consideration", enough private disgust. It's time for UEFA and Europe to take action against what FIFA and Infantino are doing to football: www.theguardian.com/football/202...

theguardian.comUefa has to show backbone: concrete action can make Fifa’s World Cup plans untenable | Nick AmesEuropean football has shown an increased willingness to talk tough with Fifa but words can only be wielded so many times

github.comRelease 0.35.1 · slackhq/circuitNew Pluggable Screen/PopResult persistence with CircuitSaver Circuit's saveable back stacks no longer mandate how Screens and PopResults are persisted. A new CircuitSaver abstraction in circuit-run...

16 July

Circuit 0.35.1 begins removing Parcelable requirements and migrating to AndroidX retain! github.com/slackhq/circ...

First day at OpenAI!

Contributed R8 support to shadow, main benefit is you could produce pretty optimized uber jars now (on top of just tree-shaking). Should be pretty handy for CLIs. github.com/GradleUp/shadow/re...

github.comRelease 9.5.0 · GradleUp/shadowAdded Check DuplicatesStrategy for merging transformers. (#2026) This will log warnings when an incompatible DuplicatesStrategy (e.g., EXCLUDE) is applied in Gradle configuration for built-in Reso...

github.comMoshiX/moshi-ir/moshi-kotlin-tests/build.gradle.kts at main · ZacSweers/MoshiXExtensions for Moshi including IR plugins, moshi-sealed, and more. - ZacSweers/MoshiX

6 July

Also handy for testing your library against R8/minification conditions. Good if you do some reflection and have proguard rules you ship with your library. Example of doing this (manually) here: github.com/ZacSweers/Mo...

youtu.beMetro Under the Hood | Zac SweersRecording brought to you by American Express. https://americanexpress.io/kotlin-jobs

2 July

My "Metro Under the Hood" talk from KotlinConf is available on YouTube now! Video: youtu.be/KVmogsSbic8 Slides: speakerdeck.com/zacsweers/met...

2 July

Apologies for the contrast issues on some slides in the video. My slides were black and white, the video processing for some reason gave it a Solarized Light theme

github.comRelease 1.3.0 · ZacSweers/metroNew [IR] Revamp graph-validation diagnostics with structured output. Taking some inspiration from Rust error messages. Stable diagnostic IDs Compact dependency chains Aligned binding traces...

Metro 1.3.0 has rich diagnostics and experimental runtime tracing! github.com/ZacSweers/metro/re...

And finally, this release's copilot: Honey! She's a deaf 6-month-old red heeler and chaos incarnate.

h/t @rahulrav.com for starting the tracing work!

Metro 1.3.0 has rich diagnostics and experimental runtime tracing! github.com/ZacSweers/metro/re...

Runtime tracing is a new integration with the upcoming androidx.tracing 2.0. If enabled, you just pass a Tracer instance into your graph and Metro will generate code that traces binding materialization throughout your graph. This is especially useful for profiling app startup or a CUJ.

Plus a bunch of other improvements to diagnostics and the usual laundry list of bug fixes!

Metro 1.3.0 has rich diagnostics and experimental runtime tracing! github.com/ZacSweers/metro/re...

Rich diagnostics is something I've wanted to work on for a while and takes a lot of inspiration from Rust. Same focus on detail and bouncing you in the right direction, but now with markup and diagrams! This works safely in the IDE as well, where IDE builds will gracefully fall back to plain ascii.

zacsweers.devHow to Take an 11 Month SabbaticalA sequel to the last one, but a bit longer. On Leaving Slack After nearly 6 years, I left Slack in August of 2025. It was for a combination of reasons that added up to "it's time". The biggest rea...

29 June

How to Take an 11 Month Sabbatical www.zacsweers.dev/how-to-take-...

zacsweers.github.ioPerformance - MetroA multiplatform dependency injection framework for Kotlin

24 June

Coming in Metro 1.3.0! Was awesome working with Rahul on this

Rahul Ravikumar@rahulrav.com

I collaborated with @zacsweers.dev (who did most of the heavy lifting) to add automatic tracing for Graph bindings generated by Metro. If you are using DI, then you should be cognizant of it's costs. Metro automatically adds traces for all generated bindings when you enable Runtime tracing.

zacsweers.devIntroducing KemptFormatting should be boring, in the best possible way.

23 June

Introducing kempt: a single-entry point CLI that delegates to language-specific formatters with easy installation, automatic binary management, git hook integration, license headers, whitespace handling, and simple configuration. www.zacsweers.dev/introducing-...

21 June

So fucking proud of this team 🇨🇼 . One more to go in Philly

commonhaus.org🎉 OkHttp, Okio, Retrofit, and SQLDelight join Commonhaus!OkHttp, Okio, Retrofit, and SQLDelight join Commonhaus under the lysine.dev banner

21 June

Yes every game is effectively a home game for the other team. We were the ones partying in the stadium after

Zac Sweers reposted

Commonhaus Foundation

@commonhaus.org

17 June

🎉 OkHttp, Okio, Retrofit, and SQLDelight join Commonhaus! www.commonhaus.org/activity/315...

central.sonatype.orgMaven Central Publishing Limits

16 June

Super sympathetic to Sonatype's situation, hosting isn't free. But announcing this with paltry limits and no public pricing options (a sales contact ain't it) is bad for everyone and going to be a major disruption to the JVM and Kotlin ecosystems. central.sonatype.org/publish/mave...

@brandonfriedman.bsky.social

16 June

Also charting gore to justify this

Zac Sweers reposted

Brandon Friedman

11 June

Best thing about Mamdani is that he's one of the only Democrats who understands you can just do things

Mayor Zohran Kwame Mamdani@mayor.nyc.gov

When James Dolan cancels the watch party outside MSG, we bring the watch party to you. Thanks to the @nba.com, Knicks Game 4 is now playing on dozens of LinkNYC screens across our city. LGK.

github.comRelease 1.2.0 · ZacSweers/metroNew [interop] This release introduces experimental support for Hilt @InstallIn and @EntryPoint interop. Enabled with metro { interop { includeHilt() } } A @DependencyGraph(<scope>) automatically ...

10 June

Metro 1.2.0 has Hilt interop, provider inlining, improved compiler performance, and leaner runtime primitives! github.com/ZacSweers/metro/re...

Zac Sweers reposted

KetAnthropic JoshAI

@ketanjoshi.co

10 June

I've been a broken record on this for three years and I'll be a broken record for as long as that fucking website exists: X is a viciously racist far-right organising platform that ONLY WORKS because a huge number of centrists, lefties and progressivs cannot stop propping it up

yahoo.comElon Musk accused of fuelling unrest after Belfast knife attackThe use of social media in planning violent protests over the Belfast knife attack has drawn condemnation, with Britain's ruling Labour Party accusing Elon Musk of stoking divisions. The tech billiona...

Zac Sweers reposted

Josh

@stagg.me

9 June

⚡️Circuit 0.34.0 is out 🚀 🆕 SubCircuit - A lightweight presenter/UI pair for reusable components that need to cooperatively delegate events to a parent. Plus a new composite-presenter Inbox sample, support for Compose 1.11, and a variety of fixes! github.com/slackhq/circ...

github.comRelease 0.34.0 · slackhq/circuitSubCircuit SubCircuit is a lightweight version of Circuit for rendering nested presenter/UI pairs that delegate events to an outer component rather than handling navigation themselves. Use it for n...

8 June

Moreover, what Apple and Google and all these other companies haven't learned that movie studios have is you need to make the non-human companion character functionally a cat. Toothless, Rocky, BB8, R2, Stitch, WALL-E, Groot, list goes on

Zac Sweers@zacsweers.dev

I want a Rocky voice in all these assistants

8 June

I want a Rocky voice in all these assistants

Zac Sweers reposted

Rodger Sherman

@rodger.bsky.social

27 May

—Guy gets a potato egg and cheese taco —republicans decide to make it a campaign issue —they call him vegan instead of vegetarian even though vegans don’t eat eggs or cheese, because vegan sounds “worse” —guy isn’t even vegetarian, he just likes tacos

Aaron Rupar@atrupar.com

RNC Chair Joe Gruters: "Tala-freako is a creep. He's a vegan. He thinks God is nonbinary. He wants to mutilate children."

speakerdeck.comMetro Under the Hood

22 May

Here are the slides: speakerdeck.com/zacsweers/me...

Zac Sweers@zacsweers.dev

I'll be giving a talk about Metro's internals tomorrow at @kotlinconf.com! This'll be an advanced talk that assumes familiarity with Metro, and is a sort of part 2 of my "Navigating Dependency Injection with Metro" talk last year. You can find it here: www.youtube.com/watch?v=jVfm...

Also highly recommend @bnorm.dev's talk on compiler plugins here: www.youtube.com/watch?v=9P7q...

youtube.comWriting Your Third Kotlin Compiler Plugin | Brian NormanYouTube video by Kotlin by JetBrains

github.comRelease 1.0.1 · ZacSweers/metroNew [FIR] Add a diagnostic warning that @Module.subcomponents is ignored by Metro (when Dagger interop is enabled). [FIR] Add a diagnostic error for annotating @AssistedInject types with @Contribu...

13 May

Metro 1.1.0 and 1.0.1 are out now! This is largely a performance release. They are identical except 1.1.0 drops Kotlin 2.2.0 - Improved compiler performance - Lots of tracing improvements - SwitchingProvider now generates tableswitch bytecode - Kotlin 2.4.20 support github.com/ZacSweers/metro/re..

Another fun one here is that Metro now uses Metro internally! yodawg.png

github.comRelease 1.1.0 · ZacSweers/metroThis release is identical to 1.0.1 but removes support for Kotlin 2.2.20 and 2.2.21. Consider sponsoring Metro's development What's Changed Remove 2.2.20 support by @ZacSweers in #2281 Full Chang...

14 May

Speaking of dawg, this release’s copilot: Coral! Coral’s been through hell and back, even by shelter dog standards. But despite that she’s incredibly sweet and gentle. Very much enjoyed watching her last week for another volunteer.

1.1.0 release notes are here, but the bulk of the interesting notes are in 1.0.1! github.com/ZacSweers/metro/re...

13 Aug 2025

Always ask why the position was available

8 Aug 2025

Last day at Slack! Nothing planned next yet, gonna enjoy some time off 🌴

8 Aug 2025

4970 PRs, 1363354 lines of code changed, 8067 PRs reviewed across 19 repos 🫡

8 Aug 2025

I’ll also continue to co-maintain Circuit, Foundry, EitherNet, and our custom lints 👨‍💻

github.comAnvil Moves to Maintenance Mode · Issue #1149 · square/anvilHey all! We wanted to share an update on the state and future of Anvil. We previously published a roadmap covering the major work we had planned, including K2 support and making Anvil a standalone ...

18 July 2025

Metro wouldn’t be where it is without the road that Anvil paved before it. I’ve really enjoyed working with Joel and Jacob on several Metro features already, with @ralf-wondratschek.com in its early design phase, and really looking forward continuing to work with all of them. Future’s bright 🚇

👻 Ray 🕷️ Ryan 👻@rjrjr.com

Anvil is approaching the icebox, long live Metro. github.com/square/anvil...

3 May 2025

Big Friday over here - Foster pup Helga got adopted! - Raced another mile and lowered my (adult life) best to 4:46 in a big breakthrough - Finished a huge rewrite of Metro's internal binding graph, runs in O(V+E) complexity now + fixed a few bugs along the way