Hi guys, I've been using Kotlin for 4+ now, but ne...

# server

[Grzegorz Aniol]

Hi guys, I've been using Kotlin for 4+ now, but need to ask for a friend :), who wants to convince CTO for Kotlin adoption on backend in fully java backend ecosystem. I'm looking for strong, up to date numbers, charts, reports, success stories, big deployments etc. basically no bulshit , hypes, as he has strong java/dev experience. Anyone have seen something good recently? Thank for the help :)

[Leonardo Silveira]

go for item 90: https://www.thoughtworks.com/content/dam/thoughtworks/documents/radar/2023/09/tr_technology_radar_vol_29_en.pdf

[horse_badorties]

Google talking about adopting Kotlin for their internal server-side development, which is mostly Java/JVM. Some of the numbers like 2900 developers doing Kotlin at Google are quite impressive.

https://youtu.be/hXfGybzWaiA?t=974▾

[Cies]

We ported 250k lines over from Groovy+html (to Kotlin with kotlinx.html) and Java. We started as a Java-Kotlin mixed project. The dev team really likes Kotlin and wanted to port the remaining 30% over "all at once".

The compile times are worse (it could be mostly due to kotlinx.html), the interop with Java libs has lots of rough edges (Hibernate and jOOQ mainly), but you quickly learn how to live with them. The improved type-safety is great, but does not work for interop with most Java libs (platform types, as Kotlin call them, are our main source of NPEs now).

Looking back I'd say for absolute predictability and compile speed stick to Java (there are ways to extend it like explained here: https://engineering.fb.com/2022/11/22/developer-tools/meta-java-nullsafe/). For developer happiness go with Kotlin: shorter code, clean on the eyes, some really nice language features that allow you to create beautiful APIs.

Also, IntelliJ is not on feature parity yet wrt refactor tools. Mainly the move-tool is missing when writing Kotlin. And there are some things that do not work well in mixed Java-Kotlin project.

For our team/product it was worth it.

[edrd]

Also check:

https://kotlinlang.org/lp/server-side/case-studies/

[Venkat]

Www.Porter.in is completely on kotlin backend with ktor
They have 140+ Microservices and hosted in aws.
They have high throughput services

[Vaclav Hodek]

The whole backend of localazy.com is pure Kotlin/jvm.