Hacker News: jmarlow47

New comment by jmarlow47 in "Java sealed classes and exhaustive pattern matching"

jmarlow47 — Sun, 18 Oct 2026 19:56:46 +0000

That's valid. Kotlins nullable types do help tremendously in that regard with AI-generated code. If Java nailed a nullable type system that's actually a win for Kotlin as well since Kotlin has to support "platform types" where it can't tell if Java code is producing null or non-null types.

That's probably the largest gap in usability.

New comment by jmarlow47 in "Java sealed classes and exhaustive pattern matching"

jmarlow47 — Sun, 18 Oct 2026 17:09:22 +0000

Kotlin feels like it's having an identity crisis. The gap between the two languages continues to decrease. Kotlin is trying to be server-side, Android, but also every other platform (KMP). Feels like everything is brand new and also deprecated at the same time, always moving on to something new.

Maybe Roman really was the soul and it lost its touch without him?

I guess in the age of AI it doesn't matter since a few years from now, if you change your mind, you can just ask Jeeves to one-shot rewrite it back to Java.

New comment by jmarlow47 in "The Brain Sandwich"

jmarlow47 — Sun, 18 Oct 2026 14:33:20 +0000

This approach appears valuable for personal growth as an engineer, yet it demands discipline that may not yield returns in corporate settings. Specifically:

> The rule of thumb is: if you can’t explain what’s changing and why, it’s not ready for someone else to take a look

I have observed firsthand that the metric or "understanding" can be irrelevant to management. When delivery dominates, understanding can be deferred to future agents who will gladly consume your codebase and convince you they grasp it, and further, that you do too. If I invest substantial effort in my PRs only for them to be /review'd, does it still matter? Perhaps reviewers should practice brain sandwich as well.

The worst offenders seem to sit at either extreme: fully AI firms that treat understanding as a human weakness and prioritize outcomes alone, or large corporate teams building internal CRUD apps whose middle management merely pretends to value good engineering to satisfy finicky senior engineers.

Not a criticism on the authors work at all, I like the idea (and I don't think they were trying to solve anything to do with work culture), but ultimately if my company doesn't find my practice valuable, I can't easily justify taking it on. Especially if I have to sell to them that I'm going to be spending _more_ time delivering. Fun times!

New comment by jmarlow47 in "JDK 28"

jmarlow47 — Sun, 18 Oct 2026 00:03:45 +0000

It's really refreshing to see the pace of Java development pick up so much over the past few years.

The last few years of server-side has been on Kotlin for me, however, modern Java is looking more and more like anything I'd need in a language.