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Petri Kainulainen @petrikainulainen.bsky.social · 5d

19 interesting SW development blog posts which I read in September 2025. HIGHLIGHTS: why I am declining your AI generated MR, keeping secrets out of logs, and are the SOLID principles outdated

Software Development Monthly 9 / 2025 - Petri Kainulainen

The software development monthly highlights 19 interesting or useful blog posts which I read during September 2025.

www.petrikainulainen.net

Petri Kainulainen @petrikainulainen.bsky.social · 12d

21 interesting test automation articles which I read during September 2025. Highlights: the Tetris principle, how to optimize your Spring Boot integration tests, and how to write your first performance tests with Grafana k6.

Clean Test Automation Monthly 9 / 2025 - Petri Kainulainen

The clean test automation monthly highlights 21 interesting or useful test automation blog posts which I read during September 2025.

www.petrikainulainen.net

1

Petri Kainulainen @petrikainulainen.bsky.social · Sep 9

An interesting article which explains why some people cannot pass technical interviews which include a live coding session.

Live coding sucks

Live coding measure stress, not coding skills

hadid.dev

Petri Kainulainen @petrikainulainen.bsky.social · Sep 9

When you say tech bros, do you mean people like Bezos, Zuckerberg and Musk, or are you referring to "normal people" who might or might not vibe code?

1 2

Petri Kainulainen @petrikainulainen.bsky.social · Sep 9

You should always take responsibility for the code you commit.

I Know When You're Vibe Coding

I shouldn’t have to care about this. I don’t want to care about how someone’s code gets into the IDE. Whether you wrote it by hand, copied it from a forum…

alexkondov.com

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Petri Kainulainen @petrikainulainen.bsky.social · Sep 8

15 interesting SW development blog posts which I read in August 2025. HIGHLIGHTS: I Know When You Are Vibe Coding, AWS deleted my 10-year account and all data without warning, and Live Coding Sucks.

Software Development Monthly 8 / 2025 - Petri Kainulainen

The software development monthly highlights 15 interesting or useful blog posts which I read during august 2025.

www.petrikainulainen.net

Petri Kainulainen @petrikainulainen.bsky.social · Sep 4

Why I Fired Google and Gave an AI Chatbot a Shot: www.petrikainulainen.net/software-dev...

Petri Kainulainen @petrikainulainen.bsky.social · Sep 1

HIGHLIGHTS: how to write automated tests for a legacy application that cannot be unit tested, learn to test production-ready Spring Boot applications, and how to write Playwright tests which verify that the expected interactions happen between our UI and REST API.

Clean Test Automation Monthly 8 / 2025 - Petri Kainulainen

The clean test automation monthly highlights 15 interesting or useful test automation blog posts which I read during august 2025.

www.petrikainulainen.net

Petri Kainulainen @petrikainulainen.bsky.social · Aug 1

HIGHLIGHTS: the rules and roles of AI assisted testing, how to create a useful logging config for Spring Boot tests, and learn to write performance tests with Playwright and Lighthouse.

Clean Test Automation Monthly 7 / 2025 - Petri Kainulainen

The clean test automation monthly highlights 11 interesting or useful test automation blog posts which I read during July 2025.

www.petrikainulainen.net

1

Reposted by Petri Kainulainen

Michael Simons @rotnroll666.bsky.social · Jul 1

New in my toolkit (after resilience4j and Spring Retry): #failsafe

failsafe.dev

Nice api, clear docs, easy and flexible to integrate and use. Well done.

#java #awesomeEcoSystem

Fault tolerance and resilience patterns for the JVM

Failsafe website

failsafe.dev

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Petri Kainulainen @petrikainulainen.bsky.social · Jul 1

Interesting article.

React Still Feels Insane And No One Is Talking About It

mbrizic.com

Petri Kainulainen @petrikainulainen.bsky.social · Jul 1

I will grab Elden Ring and Horizon Forbidden West from the Steam's summer sale. The price is decent and I guess these (+ Rocket League) will keep me entertained for the rest of this year.

Petri Kainulainen @petrikainulainen.bsky.social · Jun 30

HIGHLIGHTS: a good test name is a sentence, how to write parameterized test classes with JUnit 5, and supercharge your Playwright tests with the Chrome DevTools Protocol.

Clean Test Automation Monthly 6 / 2025 - Petri Kainulainen

The clean test automation monthly highlights 14 interesting or useful test automation blog posts which I read during June 2025.

www.petrikainulainen.net

1

Petri Kainulainen @petrikainulainen.bsky.social · Jun 28

I use a somewhat similar approach.

How I write production-ready Spring Boot applications

This blog post will explain how I currently write Spring Boot applications. I have been writing Java for over 25 years, and most of that involved Spring and its ecosystem. I will talk about how I arch...

www.wimdeblauwe.com

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Petri Kainulainen @petrikainulainen.bsky.social · Jun 10

I have come to the conclusion that I will monetize my blog. Have you done the same? If yes, what membership plugin / service did you use?

Petri Kainulainen @petrikainulainen.bsky.social · Jun 10

This is an excellent post.

Siva @sivalabs.in · Jun 9

Protecting Your Mental Health While Being On Social Media

www.sivalabs.in/protecting-y...

Protecting Your Mental Health While Being On Social Media

Social media is a double-edged sword. If used properly, it can be immensely helpful. Personally, being on social media, especially on Twitter, helped me to connect with amazing people across the world...

www.sivalabs.in

2

Reposted by Petri Kainulainen

Marc Philipp @marcphilipp.de · Jun 7

✨ New blog post: "STF Milestone 4: Parameterized test classes"

JUnit 5.13 introduced parameterized test classes (in addition to methods). They are a powerful testing tool that has long been missing from JUnit Jupiter...

👉 marcphilipp.de/blog/2025/06...

@ParameterizedClass
@ValueSource(strings = {"foo", "bar"})
class SomeTests {
@Parameter String value;

@Test
void shouldNotBeNull() {
assertNotNull(value);
}
@Test
void lengthShouldBeThree() {
assertEquals(3, value.length());
}
}

11 31

Reposted by Petri Kainulainen

Siva @sivalabs.in · May 31

I think people go through various phases of using AI:

1. AI is just a hype
2. AI seems to be helpful
3. Wow, AI is amazing and it's going to take away our jobs
4. OMG, AI made my codebase a mess
5. Okay, so I need to do the thinking and use AI to carry out the tasks.

1 1 3

Petri Kainulainen @petrikainulainen.bsky.social · May 31

That's actually how I did it. So, I wrote the guidelines with Markdown and then opened it, asked assistant to check my instructions and then for example generate some code. Can you use guideline files if you aren't using JUnie?

Petri Kainulainen @petrikainulainen.bsky.social · May 31

I am testing the Jetbrains AI Assistant and I have noticed that I can pass guidelines to AI chat by following these steps: 1) Open the markdown file which contains the guidelines 2) Open AI Chat and allows access to code base 3) Ask the assistant to read guidelines and generate code. Interesting.

1 1

Petri Kainulainen @petrikainulainen.bsky.social · May 31

Highlights: how to generate good tests with AI, 3 ways to run a Docker container with Testcontainers when we are writing integration tests for Spring Boot applications, and vibe testing with Playwright.

Clean Test Automation Monthly 5 / 2025 - Petri Kainulainen

The clean test automation monthly highlights 23 interesting or useful test automation blog posts which I read during May 2025.

www.petrikainulainen.net

2 2

Petri Kainulainen @petrikainulainen.bsky.social · May 26

If you want to generate Spring controllers with openapi-generator-maven-plugin and you don't want to include Swagger annotations in the generated code, this comment describes the configuration you have to use: github.com/OpenAPITools...

[BUG] [SPRING] annotationLibrary is ignored · Issue #11460 · OpenAPITools/openapi-generator

Hi. I'm using the latest version of the generator (5.3.1) and, according to the spring generator documentation, I should be able to not generate the Swagger annotations by setting annotationLibrary...

github.com

1

Petri Kainulainen @petrikainulainen.bsky.social · May 26

Good point.

Fluent APIs Are More Than Just Chaining · Poutsma Principles

poutsma-principles.com

Petri Kainulainen @petrikainulainen.bsky.social · May 22

Sure thing. I actually got guide excited about the coding guidelines because that sounds like a great way to both share guidelines for team members and of specify what kind of code should be generated.

1

Petri Kainulainen @petrikainulainen.bsky.social · May 21

Sometimes vibe-coding is relaxing, and sometimes it's not.