45 engineers on Hacker News describe using Kotlin first-hand: 21 endorse it, 2 regret it, 4 are mixed.
“we migrated one of Denmark's most used Android apps with one million lines of code powered by Java threads, into Kotlin coroutines”
endorse · production · adrianblp · 2026-06-30 · source ↗ · wrong label?“writing new Java code is discouraged and you should instead use Kotlin for backend services”
endorse · production · aarroyoc · 2025-12-07 · source ↗ · wrong label?“Here are some of my favorite Kotlin improvements over Java that I leverage all the time”
endorse · production · mrudolph22 · 2024-12-23 · source ↗ · wrong label?“In my main gig we run on kotlin (fintech/accounting saas) and I absolutely despise it, the overhead is massive.”
regret · production · RamblingCTO · 2022-10-19 · source ↗ · wrong label?“We've had zero, absolutely zero issues with all the other stacks.”
endorse · production · brabel · 2022-07-16 · source ↗ · wrong label?“There is one language, it is Kotlin... Kotlin is kind of awesome for this actually.”
endorse · production · jillesvangurp · 2022-05-26 · source ↗ · wrong label?“I'm currently working on a project where we use Kotlin instead of Java. Probably wouldn't have taken the job if it was with Java and Kotlin makes it quite fun.”
endorse · production · esarbe · 2021-12-24 · source ↗ · wrong label?“We've been using it for 4+ Years for a backend web service and a few other libraries at my current company.”
endorse · production · 4 yr · twbarber · 2020-12-19 · source ↗ · wrong label?“I've been using kotlin in the backend for a few years now, in a team of more than 50 engineers.”
mixed · production · knur · 2020-12-19 · source ↗ · wrong label?“We've switched from Java to Kotlin with Arrow for all our back end work. We couldn't be happier”
endorse · production · bedobi · 2020-12-11 · source ↗ · wrong label?“had no scaling problems with Kotlin and I've been using it for the last five years”
endorse · personal · 5 yr · thu2111 · 2020-12-11 · source ↗ · wrong label?“We ditched kotlin as a server side language. We initially were very enthausiastic about it, but it turned out to have quite some annoying bugs.”
regret · production · holoduke · 2020-10-29 · source ↗ · wrong label?“We had to use arrow library to make Kotlin more like Scala... Kotlin is a better Java, so I can understand the appeal. I'd never start a new project in Java when Kotlin is available.”
mixed · production · 1 yr · ayberk · 2019-12-17 · source ↗ · wrong label?“We use Kotlin but you don't have to know it to apply.”
endorse · production · thu2111 · 2019-12-17 · source ↗ · wrong label?“I recently started working on Kotlin. Kotlin is the better Java than Scala and is much easier for someone to pick up.”
endorse · personal · manojlds · 2019-12-17 · source ↗ · wrong label?“This 'nullless' code is nice in some places, especially with UI lifecycles calling code repeatedly, but other times it just changes the type of error you debug.”
mixed · production · tarkin2 · 2018-12-04 · source ↗ · wrong label?“we chose to: 1. Use Kotlin over Java”
endorse · production · nevi-me · 2018-07-02 · source ↗ · wrong label?“I have been using kotlin in prod for over a year now on Android”
endorse · production · 1 yr · on_and_off · 2018-05-23 · source ↗ · wrong label?“We've not had any problems that have been related to our use of Kotlin.”
endorse · production · vishbar · 2017-12-12 · source ↗ · wrong label?“we soon wanted to begin using pure, idiomatic Kotlin, so eventually decided to start again and port what we needed”
endorse · production · tarkaTheRotter · 2017-11-14 · source ↗ · wrong label?“we've switched to Kotlin from Java a little over a year ago with great results.”
endorse · production · 1 yr · iammiles · 2017-08-21 · source ↗ · wrong label?“We use Kotlin daily for back-end services as a cleaner and more powerful Java”
endorse · production · maximusjesse · 2017-05-03 · source ↗ · wrong label?“I've been using Kotlin for about three months to develop an Android application that is now in production.”
endorse · production · kcorbitt · 2015-07-25 · source ↗ · wrong label?“I have written Kotlin for an Android app now in production.”
endorse · production · staltz · 2015-07-25 · source ↗ · wrong label?“I've been using Kotlin on-and-off as a Java replacement and I've really enjoyed it.”
endorse · personal · doomspork · 2015-07-25 · source ↗ · wrong label?“I write some parts of Telegram app in Kotlin. Pretty good after plain java. I can't rely on it in production yet”
endorse · personal · ex3ndr · 2015-07-25 · source ↗ · wrong label?“I have been using Kotlin in production for 2 Android apps since october 2013. It made things simpler to write, develop and maintain.”
mixed · production · 2 yr · lakedaemon · 2015-07-25 · source ↗ · wrong label?“I used the project to learn Kotlin and Jetpack Compose. Everything is strictly native using Room and Media3/ExoPlayer.”
neutral · personal · mike_pol · 2026-11-03 · source ↗ · wrong label?“I've been using Mockito for about 4 years, all in Kotlin.”
neutral · personal · 4 yr · t-writescode · 2025-12-28 · source ↗ · wrong label?“Same when we introduced Kotlin for example. I was instantly productive”
neutral · production · tharkun__ · 2024-12-04 · source ↗ · wrong label?“monolithic Kotlin web backends, deploy clients to multiple different app store like platforms”
neutral · production · maccard · 2023-12-17 · source ↗ · wrong label?“we introduce another hurdle because we only use Kotlin.”
neutral · production · RamblingCTO · 2023-10-10 · source ↗ · wrong label?“I encounter this endlessly in prod code with both Python and Kotlin chained functional style garbage.”
neutral · production · n0tth3dro1ds · 2022-12-21 · source ↗ · wrong label?“some smaller apps and new code was using Kotlin for a while now.”
neutral · production · strulovich · 2022-10-25 · source ↗ · wrong label?“We use kotlinx serialization in a multi-platform library.”
neutral · production · jillesvangurp · 2022-08-05 · source ↗ · wrong label?“We run our Spring/Kotlin JVM servers on cheap vms in Google cloud and in another data center using openstack.”
neutral · production · jillesvangurp · 2022-07-22 · source ↗ · wrong label?“Kotlin w/Gradle. Build + Deploy single command `gradle deployStage`.”
neutral · personal · jpgvm · 2021-10-13 · source ↗ · wrong label?“The backend team has gone from DIY php to symphony then to java and finally to kotlin.”
neutral · production · apineda · 2021-06-27 · source ↗ · wrong label?“The UI was written with Inferno + MobX and the backend in Swift/C#/Kotlin depending on the platform.”
neutral · production · pier25 · 2021-03-05 · source ↗ · wrong label?“We're using the Expedia implementation for Kotlin and Spring Boot.”
neutral · production · 0.5 yr · jillesvangurp · 2020-12-16 · source ↗ · wrong label?“I've been using the Expedia implementation for Kotlin & Spring Boot lately”
neutral · personal · jillesvangurp · 2020-12-14 · source ↗ · wrong label?“Coming from Java, Kotlin, C#, Python I first thouhgt Go was a bad joke”
neutral · personal · challenge441 · 2020-07-23 · source ↗ · wrong label?“One reason to do it like this is that we want to leverage the design philosophy of Kotlin.”
neutral · production · joostdevries · 2019-12-17 · source ↗ · wrong label?“It may be a bit verbose (we switched to Kotlin later on)”
neutral · production · buremba · 2019-11-16 · source ↗ · wrong label?“Server is still Kotlin and we just export the data transfer classes as Typescript definitions”
neutral · production · gregopet · 2019-01-06 · source ↗ · wrong label?