Rafał Maciak

Software engineer. Java, Kotlin.

[Rafał Maciak @r_maciak]

@kotlinconf 2025 was amazing! Learned a lot, got inspired, and caught all the #Kotlin keynote news.
Thanks to the speakers, the @jetbrains team, and congrats to @ArturSkowronski for rocking the stage before the party! Can’t wait for next year.

P.S. Happy birthday #Java 🎂🥳

[Rafał Maciak @r_maciak]

Part 2 of my #Ktor via #SpringBoot lens is live. It covers:
- HTTP requests
- client usage
- testing

https://t.co/sdkrd79QeZ

[Rafał Maciak @r_maciak]

I’ll be attending @kotlinconf starting Thursday, May 22nd. I’d love to chat about any topic, but especially #Kotlin, of course! 😊

Feel free to shoot me a DM to set up a coffee.

See you there!

[Rafał Maciak @r_maciak]

#SpringBoot pros - have you tried #Ktor yet? 🤔

My new guide covers app setup, engine choices, app configuration & DI with Koin.

https://t.co/rw4GWBe2AM😊

Part 2 coming soon!

#Kotlin #KotlinServerSide

[Rafał Maciak @r_maciak]

Read our latest article about Kotest:
https://t.co/spfJtTHaBg

[Rafał Maciak @r_maciak]

Testing in #Kotlin? You could use #JUnit, TestNG or even Groovy+Spock, but why not harness Kotlin’s full power with #Kotest?

Multiple DSLs (FunSpec, ShouldSpec…), fluent assertions, property & data‑driven tests-all hooked into #Gradle, #coroutines, #MockK, #Ktor & #SpringBoot

[Rafał Maciak @r_maciak]

The business-IT disconnect hurts organizations with misunderstandings, slow delivery & added complexity.
In our latest article, @mostruszka shares how to bridge this gap:

Shared language
Common goals
Clear boundaries
Big picture understanding

https://t.co/2mw3hPm2Am

[SoftwareMill @softwaremill]

The trade-offs between traditional HTML-based templates and Kotlin's type-safe DSL, highlighting readability, extensibility, and practical usability in server-side rendering of both approaches.

All of that in the new article by 🐗 Michał Pierściński

https://t.co/koqz7x11I6

#Kotlin #KotlinServerSide

[Rafał Maciak @r_maciak]

@mostruszka “The trouble with functional programming is functional programmers” xd

[Rafał Maciak @r_maciak]

And if you need help with Kotlin development, feel free to reach out to @softwaremill or contact me directly.

[Rafał Maciak @r_maciak]

Should your company consider switching to #Kotlin?

As always, the answer is – it depends . But let’s explore what benefits Kotlin could bring to your company. (thread)

[Rafał Maciak @r_maciak]

Instead, you can gradually integrate Kotlin into your current solutions and start taking the benefits from day one.
Want to read more? My colleague has just released an in-depth article on this topic - https://t.co/ZRgy7dqHSc

[Rafał Maciak @r_maciak]

On top of all that, Kotlin is built on the JVM-a mature and battle-tested platform trusted by enterprises worldwide. Most importantly, Kotlin seamlessly integrates with existing Java codebases, meaning you don't have to invest enormous time in rewriting your systems.

[Rafał Maciak @r_maciak]

Improved developer satisfaction-Kotlin is a modern and versatile language that blends multiple programming paradigms (functional and OO), making it an attractive choice for talented developers. Adopting #Kotlin can attract and retain top talent, ultimately reducing team turnover.

[Rafał Maciak @r_maciak]

Built-in concurrency - Kotlin’s tools, such as Coroutines and immutability, make writing asynchronous code straightforward, reducing the complexity and pitfalls of traditional multithreading. This leads to fewer errors, better maintainability, and increased productivity.

[Rafał Maciak @r_maciak]

Increased productivity - Kotlin’s concise syntax, extensive built-in features, and top-notch IDE support (IntelliJ IDEA) reduce boilerplate code and streamline development. This means your team can deliver faster and accelerate time-to-market with less code to write and maintain.

[Rafał Maciak @r_maciak]

Null safety - while this is a technical concept, null safety significantly reduces the likelihood of runtime errors. Fewer errors mean fewer outages, which can directly translate to minimized losses and improved user satisfaction.

[Rafał Maciak @r_maciak]

After Monday’s unexpected #circus performance 🎪 (clown pulled my wife and me onto the stage), yesterday I had the pleasure of discussing my experience with #microservices at Lublin #JUG.

I hope it was a bit less comical than Monday's incident 🙈

Thanks for having me 😃

[Rafał Maciak @r_maciak]

Today, I'm going to speak at @LublinJUG about my successes and failures with #microservices 😊

Who will I meet there?
#lublin #jug

[Rafał Maciak @r_maciak]

Link to the article: https://t.co/ftVMpCQ4oj

[Rafał Maciak @r_maciak]

Toss out sticky notes, not code!

In the latest article from @softwaremill's #projectDDD, @mostruszka describes real-life scenario where starting with "coding on Miro" saved developers a lot of effort and frustration, and of course, saved money for the business. Link in thread.