I want to buy this book I want to learn Java and bit concepts of OOPs then I want to continue DSA in java only so it's this book worth it and can anyone give a short review abt it pros and cons. (Ik C programming and bit Python)

Firstly I learned java on brocode ,felt like learning in school.This is 2nd time I ma learning java .I’m currently working through the beginner course on the Telusko channel to build a solid foundation in Java. So far, I’ve completed about 75% of the playlist, and it's been a great learning experience. I'm planning to move on to Java Spring and microservices next, is this good .Like I don't wanted learning again And I also started making notes,I wanted to learn the backend.

Yes, Java remains useful for enterprise applications, backend development, and large-scale systems. Start with core Java, OOP, collections, exception handling, and SQL, then explore Spring Boot and REST APIs to build practical applications

Hi everyone,

I’m looking for some honest advice regarding a career switch, and I’ll try to keep this as clear as possible.

I graduated with a B.Tech in Computer Science from an engineering college in Vellore during the COVID period. Due to the hiring slowdown and my own lack of preparation in DSA, I couldn’t secure a product-based role through placements or off-campus. I ended up joining a service-based company at a standard fresher package.

Initially, I was trained in Java and React, which made me think I’d be working on development projects. However, I was instead assigned to an SAP implementation project. I had no prior experience or interest in SAP, and I did try to push back, but I was told early in my career I shouldn’t be too selective and that SAP has good scope.

I decided to give it a fair shot. But after about 1.5 years in my new role, I realised this domain isn’t for me. I don’t enjoy the work and get very little job satisfaction. I tried switching internally to a Java-based project, but my manager didn’t approve my release.

At that point, I decided to prepare for a company switch into development. I started studying DSA and Java (along with Spring Boot), but I struggled with consistency. A friend encouraged me to still give interviews, and I did—but they went poorly. That experience really affected my confidence.

Since then, I’ve been stuck in a cycle: I get frustrated, start preparing again, lose momentum when things get difficult, and drop it midway. This has happened multiple times over the past few years.

I’ll be honest—I know I’ve been laid back and undisciplined, and I take responsibility for where I am right now.

Currently, I have around 5 years of experience, but all of it is in SAP. The frustration with my job and career direction has started affecting my mental health, and I’ve reached a point where I feel I have to take this seriously now.

I’ve decided to give this one final, focused attempt over the next 4–6 months to switch into a development role. I understand that my experience may not carry much weight in this domain and that I may have to start with SDE-1 / junior roles—and I’m okay with that.

What I’m looking for:

How should I realistically approach this transition in the next 4–6 months?

What should I prioritize: DSA, projects, backend development, or something else?

Has anyone here made a similar switch from a different domain into development? What worked for you?

Any advice on staying consistent and not falling into the same cycle again?

I’d really appreciate honest feedback, even if it’s tough to hear.

Thanks in advance.

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If you’re looking for a role at one of the most growing fintech companies worldwide, DM !

Hi,

I have been writing Java for more than 10 years but in the interviews recruiters ask to thing I do not do in my regular job.

What resources would you recommend to kick ass Java interviews fastest way?

Should I just prepare for OCP?

Best regards,

Hello, I am a CS graduate and currently unemployed (not a big surprise in this economy). I’ve decided to focus on Java and later Spring Boot. However, the main problem I’m facing is tutorial hell. I can’t seem to keep up with the pace of most instructors. Sometimes they teach too slowly; other times they go too fast . it feels inconsistent. I’ve found a way to counter this by working on projects. When I build things myself, I understand the concepts much more clearly and quickly. So I’ve decided to focus on Java and Spring Boot projects. However, with Spring Boot, I haven’t been able to find good projects with clear documentation. Does anyone know of official or well-documented Spring Boot project examples?

Turn real backend problems into coding exercises. Write a reference solution and tests for each one, including edge cases. The role is remote, around 15 flexible hours a week. Experience building Java APIs or services is a good fit.

Interested? Email [email protected] with “Backend Java” in the subject and a sentence about a Java service you built and how you tested it.

Hi everyone,

I'm an aspiring entry-level Java developer, currently preparing myself for my first role, and I wanted to understand something from people who are already working in the industry.

What are your actual expectations from a fresher or entry-level Java developer?

I'm not specifically asking about a list of technologies to learn. I'm more interested in understanding the capabilities and qualities you expect from someone with little or no professional experience.

What makes you feel that a fresher is genuinely ready to work as a junior developer and contribute to a real team or codebase?

Also, what separates an average entry-level candidate from someone who stands out?

I'd especially appreciate perspectives from experienced developers, senior engineers, team leads, or anyone involved in hiring and mentoring freshers.

Just trying to understand what the industry realistically expects from someone at the beginning of their software development career.

Thanks!

What are some Java backend projects that recruiters actually find impressive but aren't already on every resume? I'm looking for ideas beyond CRUD apps (library, student management, to-do, e-commerce, etc.). What projects would make you stop and check a candidate's GitHub, and why?

Do you have over a year of experience developing Java applications? I’ve got real projects waiting—no busywork. Think building scalable backend systems, APIs, or integrating with databases—the kind of work that truly makes an impact.

Role: Java Developer

Pay: $20–50/hr, depending on your experience and stack

Location: Fully remote

What’s in it for you:

Projects aligned with your skills and interests

Part-time, flexible work—perfect if you have other commitments

Passionate about Java development? Leave a message with your timezone 👀

Claude is great at Python. It hallucinates in Spring Boot.

Field injection instead of constructor injection. Custom error envelopes when you already have a wrapper. Ignoring Flyway and generating raw SQL.

Skills fix this. Drop a markdown file into `.claude/skills/` and Claude instantly codes to *your* conventions, not generic Spring Boot from 2020.

**What's in the repo:**

- Architecture: layered, hexagonal, DDD, multi-module Maven

- API: REST conventions, OpenAPI-first, RFC 9457 problem details, HATEOAS

- Data: Spring Data JPA, Flyway, Redis, transactional patterns

- Security: JWT, OAuth2 resource server

- AI/MCP: Spring AI integration, MCP server (Java SDK), AI observability

- Testing: unit → slice → integration pyramid

The MCP server skill is the most powerful one — teaches Claude to build production-ready MCP servers with the official Java SDK instead of guessing the API.

Free, MIT licensed.

→ https://github.com/rrezartprebreza/spring-boot-skills

Hello everyone. Today, I explored Java collections, particularly ArrayList, LinkedList, and HashSet. I learned some of the most commonly used methods, and I think collections are highly abstracted. For example, if I want to add an element, I can simply use the add() method, which I think is pretty cool.

I also have a question: do I need to know how to implement these collections, or is it enough to just know how they work? While learning, I came across a YouTube video where someone implemented these collections from scratch, which I felt was unnecessary, though I might be wrong. So my question is: is it mandatory to know how to implement them, or is it just good to know?

See you tomorrow!

Not so long ago I started to learn Java and at this point I've tried to find some of the Java Wallpapers that I would like to use and I found nothing. So I decided to do Java wallpaper with one of the most popular themes "Dracula". Hope you'll enjoy it.

Ever since 2019 when I started programming hating on java has been fashionable. I'm not gonna lie it got me taken seriously in online discussions. I would read about a Java feature, for example garbage collection and read about manual memory management in c++ and conclude that manual is better, not because I ran benchmarks but coz sh*tting on GC is popular..

I have since learnt java and I use it for every little thing I do. A little prototype? I pick java over python. The language is very stable and it's "finishable", meaning you can easily cover all concepts as you learn it, unlike uh cpp, c# etc.

I went from dissing the language online to using it, loving it and now defending it.

My question is: What is your usual defense for "Java sucks" compared to <put your fav lang here> ? And were you once a java hater?

My usual defense is simply to not argue but make them run java --version and if no java is installed but they are trash talking I roast them personally but that rarely happens (Only happened once where the guy even said he hates it so much he doesn't want it in his hard drive). What usually happens is I find that they are using java 1.8 and I spend the next minutes installing graalvm 21+ for them and I never hear arguments ever again.

I conducted a mock interview recently and one thing stood out to me.

I asked a Java question related to concurrency:

class Counter {
    private int count = 0;

    public void increment() {
        count++;
    }
}

“Is this thread-safe?”

The candidate said "No".

So I asked, “Why?”

He knew that it wasn't thread-safe, but explaining exactly why was difficult. He then said we need to synchronise the method.

So I asked:

“How does that fix it?” and then “What exactly is being locked here?”

That was where the interview got interesting.

He knew the terms — synchronised, volatile, race condition, etc. However, connecting them and explaining what was actually happening between the threads was harder.

It made me think about how easy it is to prepare for interviews by remembering rules.

count++ → not thread-safe → use synchronised

But the moment someone asks “Why?”, we need to understand what is actually happening.

I think that's something that's easy to miss while preparing for interviews. We can keep solving questions and memorising concepts, but it's worth stopping sometimes and asking ourselves:

“Can I actually explain why this works?” and “What happens if I change one thing?”

How do you guys prepare for the “Why?” part of interviews?

I'm preparing for placements and planning to learn Java + Spring Boot + React, but I'm worried about fresher job availability.

I keep hearing that MERN has way more opportunities for freshers and that Java/Spring jobs are harder to get as a fresher. Is this actually true?

Would Java still be a sensible choice for a fresher in 2026?

Good afternoon. I'm currently learning object-oriented Java along with Spring Boot, but I feel like I'm not making much progress. I'd like to know what you can recommend to help me move forward; it would be very beneficial for me to read your recommendations.

and why the guy from youtube doesnt have this error, though our codes are identical.

the problem is double variable on 16th stroke, but whats wrong with that?

Most developers assume JVM memory = heap.
It’s not. The heap is just one piece.

Here’s where the rest of your memory goes:

a) Metaspace
Stores class metadata. Every Spring bean, Hibernate proxy loads classes here.
Typical Spring Boot app: ~150–250MB. No cap by default.

b) Thread Stacks
Each thread ≈ is 1 MB.
200 threads (Tomcat + HikariCP + Kafka + Async) = ~200MB.
Not on heap. Invisible to heap monitoring.

c) Direct Buffers
WebClient, Kafka client, Netty allocate memory outside the heap.
Won’t show in heap dumps. Won’t trigger GC.

d) Code Cache
JIT compiled code. ~50–150MB.
Grows as your app warms up.

e) GC Overhead
A garbage collector needs its own working memory.

Here’s where it gets dangerous:

You set:
-Xmx=4g
Container memory limit = 4GB

Looks perfect, right?

Reality:
4GB heap

• 200MB metaspace

• 200MB threads

• 100MB buffers

• 100MB code cache = ~4.7GB total process memory

Container limit = 4GB → Kubernetes OOMKills your pod.

You check heap usage: only 2.5GB used.
But the pod is dead.

Because OOMKill is based on TOTAL process memory, not just the heap.

Fix:

→ Heap should be ~70–75% of container memory
→ -Xmx=4g needs ~5.2GB container
→ Or set -Xmx=3g for 4GB container

Also, cap non-heap:

-XX: MaxMetaspaceSize=256m
-XX: MaxDirectMemorySize=256m

Monitor non-heap:
/actuator/metrics/jvm.memory.used?tag=area:nonheap

OOMKilled doesn’t always mean your app used too much memory.
Sometimes it means the JVM did.