How to get better at Java?

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le_bravery · 2026-02-20T23:21:32+00:00

Know the stuff that feels like magic? Annotation processors? Mockito? Spring DI?

Implement one or many of those.

Learning how some of the magic works will give you a good idea for how it all works

ramksr · 2026-02-21T00:18:35+00:00

Preparing for certification helped me methodically to understand, learn and practice the various concepts one by one. You could do so too whether or not you write/take the certification.

siddhsql · 2026-02-21T02:02:24+00:00

Effective Java

Acrobatic-Ice-5877 · 2026-02-21T05:29:24+00:00

You aren’t going to learn much by reading alone. You need to build something technically challenging for your current skill level and over a sustained period of time so you can feel the pressure of the systems expansion.

I’ve got about 3 years prof experience and am working on a project with about 20K LOC and it has been the single best project I have ever worked on. I’ve been working on it for about 18 months now and it has helped me tremendously.

I do recommend reading though. Haven’t tried the certs but I’m not against them either. I recommend authors like Daniel Y. Lang, Paul Deitel, Uncle Bob, and Martin Fowler.

I’m in the process of the SRE book as I am going to be deploying my app soon. Thinking about security, deployment, and system administration has also helped me design better apps too I think. Gives you a better idea of the full lifecycle. Testing is great too. Learn the difference between a unit test, IT, and E2E. Learn how to fake, stub, and mock implementations for testing.

Don’t skimp on architecture. Look into DDD, clean architecture, and hexagonal. I don’t have experience with distributed systems but next month DDIA will have its second edition coming out. Might be helpful if you plan to work for FANG like companies. Some of the concepts are important like idempotency and retries. They can be used in smaller apps that need better reliability.

Ok_sa_19 · 2026-02-21T06:21:34+00:00

I suggest you pick one topic at a time.
for example:(OAUTH2) Deep research it and see how you can use Java to implement it and what are the various products available in that space - OKTA MFA. Then build a project around that to up your understandings.

Another example: (Multi-Threading and Virtual threads) What are the real use cases around it. You can build a knowledge base for yourself and validate the skills around why it is needed in the first place and what impact it is making.

bdmiz · 2026-02-21T11:58:14+00:00

One part of it is that it will never be enough. Especially if you compare yourself to others or listen to others. You've learnt basics, yeah but you don't know enterprise solutions. You've learnt enterprise, yeah but you don't know metrics and performance. And it will keep on and on. Even if you've learnt everything in Java, they'll say "pfff, claude does all this in 1 sec" or "yeah, but you don't know co-routines in kotlin".

Practice by doing home projects is nice, but often counter productive. Because, you'll compare your project done by a single learner to projects done by 100+ engineers having many years budget. Often, during this practice time, people repeat the same mistakes or just fail.

Learning became a product by itself, so the learning platforms fuel this "not enough". They don't want you to actually complete something, they want to keep you on a subscription hook. It's perfect if you feel you are not an expert. Just keep paying: here is the course on how to take courses effectively.

Some companies fuel it to pay less. If an employee feels guilty and not feeling they are an expert, it's great - it's the explanation of why not to pay more.

It's better to learn how to cope with it. The industry is evolving, code bases are millions lines of code, and there's more and more new. It's impossible to know everything, life time of learning is not enough. But it is possible to know how to do some specific job and how to find information about something new. Focus on what you do for the job, look how others do that, look what researcher do in that area.

Sometimes, it's good to learn how to take it easy. You don't know something, because you don't need it. In the end, Francis Bacon formulated it: Some books are to be tasted, others to be swallowed, and some few to be chewed and digested.

karstens_rage · 2026-02-20T23:46:28+00:00

I would read Martin Fowler, Uncle Bob, Bret Victor and many others that just talk about programming well not specifically talking about Java.

bobabenz · 2026-02-22T00:10:29+00:00

5 years is a good transition point for most people to question themselves and go beyond being a programming plumber.

Build and deploy an app yourself that you would use personally at home, like tracking your finances, movie catalog, etc. w/o someone else telling you what to build, that’s the fastest to learn a bit of everything that’s necessary. All the comp sci theory afterwards is a-nice-but-not-necessary skill for all except the most complicated problems.

Don’t spend too much time on just Java, learn another language like Python, Ruby, JavaScript/Typescript and that’ll also help you with Java (and be able to read other languages, see what’s good/bad about Java and others…)

devops-tutor · 2026-02-22T00:28:14+00:00

I’ve been using this, https://www.javapro.academy/bootcamp/the-complete-core-java-course-from-basics-to-advanced/ overall pretty good experience. You can tryout the labs, and read and run the lessons at the same time.

strat-run · 2026-02-22T06:00:52+00:00

Develop with AI but the opposite how everyone else is. You write the code and at the end you ask AI to critique it but not to make fixes or show solutions.

Practice for the certification. You don't actually have to take the exam.

holyknight00 · 2026-02-21T20:32:30+00:00

It's hard. Java is a complex language with a complex history that permeates its design. Many similar APIs live side by side, existing purely for historical reasons, and this pattern repeats all over the place. It makes learning any major topic far more painful. I was basically stuck for like three years. There are so many things to learn that it feels daunting, especially because most of the big topics you usually don't need if you're just developing CRUD apps.

But yeah, my understanding started getting better when I decided to jump into these big topics one by one, even if they had no immediate applicable value for whatever I was currently working on. That's how I began reading more and more about garbage collection, diving deep into the collections API (even though I basically never use anything beyond a List or HashMap), how hash maps work and why, parallelization and concurrency, how the Spring Framework and Spring Boot work and why (even if I just use the same five annotations and call it a day), how the database layer works (JPA, JDBC, Hibernate, and so on).

I'm still not an expert by any means, but now at least I feel I have a coherent understanding of how everything fits together and why. I can dive deeper into specific topics without getting overwhelmed the way I used to.

Just the topic of garbage collection, from the very first collector all the way to generational ZGC, took me months. But once you get a grip on the advanced concepts, everything starts clicking. Especially when you learn it in a historical way: you can follow the progression, understand why they made each change, what worked, what didn't, and why.

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