Yesterday, I attended a Java interview at Charles Schwab.

The interview was scheduled in two parts.

1. Coding/Assessment Round

In the first half, I was given a problem statement to build a simple Appointment Scheduler Java API.

The requirements were:

Appointments should not clash with each other.

Appointments should be booked correctly without conflicts.

The application should work for multiple customers at the same time.

The solution should handle concurrency without deadlocks.

The assessment was focused on building a simple Java API project around appointment scheduling.

Also, they offered a good and proper lunch in the cafeteria, which was a nice experience.

2. Interview Round

After completing the assessment, I was called for an interview round. They reviewed the assessment in the interview room itself and then asked me the following questions.

About myself

Tell me about yourself.

Why are you looking for a job change?

Production debugging

Suppose there is an issue in production, but the same issue cannot be reproduced in any of the lower environments. How would you start debugging it?

Suppose I want to change the production logging level on the fly from ERROR to DEBUG and then change it back to ERROR. How would you do that?

Microservices logging

Suppose there are three microservices communicating with each other. How would you implement logging across these services?

If there is a failure in Service 2, how would you identify where exactly the failure happened?

Trace ID / Span ID

How would you use a Trace ID and Span ID?

How would you use the Trace ID to identify where an issue occurred and which service failed?

Server restart / lost logs

Suppose a server restarted and all the error logs were lost. How would you investigate what happened?

Why do servers restart automatically?

Once completing this round.there is another round of DSA & HR.

Overall, the interview was focused heavily on Java, concurrency, production debugging, logging, microservices, and distributed tracing.

Hi everyone,

I've been working on a modern Medicare Dashboard System using pure Java Swing, and I'd like to share my latest project with you.

The system includes three different dashboard designs:

Hospital Dashboard

Medical Dashboard

Dentist Dashboard

I focused on creating a clean, modern, and user-friendly interface using standard Java Swing components without any external UI frameworks.

The dashboards include navigation menus, statistics cards, data tables, charts, patient information, and custom UI components.

I also tried to give each dashboard its own look and feel while maintaining a consistent design across the entire system.

I've recorded a step-by-step tutorial showing the design process and sharing the source code.

Watch the Full Tutorial:

https://www.youtube.com/watch?v=C7PcMyNcrTs

I'd really appreciate your feedback. What do you think of the design? Which of the three dashboards do you like most?

I'm always interested in hearing suggestions from other Java developers.

I’ve spent months learning Java, Spring Boot, Spring AI, databases, and APIs, and I’m now focusing on deployment and cloud.

While learning and building projects in all of these, I never used DSA. Yet, I’ve noticed that most companies focus heavily on DSA in interviews. Why is DSA considered so important for hiring, even though in real-world development we rarely use it? Is it mostly just a screening tool, or is there another reason?"

So a while back I started this as a boring markdown file of Java interview questions for myself. It has since spiraled into something I probably over-engineered, but here we are, figured I'd do a proper writeup instead of just dropping a link.

The core is a 300+ question bank, but not just Q&A pairs, actual structured interview-focused answers across Core Java, Java 8+, Collections, multithreading/concurrency, JVM internals and GC, exception handling, Spring Boot, Spring Security, Spring Data JPA, Hibernate, REST, microservices, Kafka, Redis, SQL, Docker, Kubernetes, AWS, design patterns, and some NoSQL (Mongo, Couchbase) thrown in. Basically anything that shows up in a backend interview loop.

DSA prep is pattern-wise and topic-wise, plus a week-wise roadmap if you want structure instead of chaos, difficulty tiers, and company-specific problems where I could find reliable sources for them.

System design section covers HLD concepts, scaling approaches, tradeoffs, the usual "how would you design X" stuff with actual explanations instead of just diagrams you have to reverse engineer yourself.

Mock interview mode throws questions at you by topic (recently added filtering so you're not just getting all 300+ questions randomly), practice mode, self-eval, and a revision workflow so you're not just doing it once and forgetting.

Then there's the stuff I'm honestly most proud of since it's not just content, it's actual product work:

• Progress tracking per question: confident / revising / weak, saved per user

• Bookmarks with a dedicated page

• Highlights that persist, saved per user

• Personal notes with a rich text editor, code block support, multiple notes per question, private to you

• Ask AI: select any text, hit a button, it opens Perplexity with an interview-focused prompt pre-loaded asking for a concise, easy explanation of whatever you selected

• Analytics dashboard: total attempted, confidence distribution, revision insights

• Search: global instant search plus filters for topic/category/DSA/system design

The newest thing and honestly the reason I'm posting is the JD Analyzer. You paste a job description and it gives you a priority radar, the skills to actually focus on, target questions, curated resources, role expectations, and a personalized roadmap. No more prepping generically and hoping it overlaps with what the role actually wants.

There's also community submission (people can submit questions, I've got an admin portal to review/approve/reject them so it doesn't turn into garbage), full JWT auth, role-based access, and it's all built on React + Spring Boot + MongoDB Atlas, deployed on Vercel/Render.

Roadmap if anyone cares: React/Angular/Python/Node prep tracks, AI-powered mock interviews (actual AI voice mocks eventually), a spaced repetition engine, company-wise tracks, a resume analyzer, GitHub profile analyzer, AI-generated study plans and flashcards, and a browser extension for one-click saving questions from wherever you find them.

It started as "I need to remember these answers for myself" and turned into basically a part time job. Still solo building this, still probably has bugs, still completely free, no premium tier, no paywall, just wanted to build something actually useful.

If you made it this far, here it is: https://learnin-prep.vercel.app/dashboard

Genuinely want feedback, especially if something's broken or confusing. Drop a comment or DM.

I’m learning Java as a beginner, and I tried to make my first "Hello World" program easier to understand by breaking down each keyword with simple explanations.

I covered "public", "class", "static", "void", "main()", "String[] args", and "System.out.println()".

Instead of just memorizing the code, I want to understand why each part is used and how it works.

I’d love to hear feedback from experienced Java developers and fellow learners. What should I improve in these notes?

#Java #LearnProgramming #CodingForBeginners

Learn the final keyword in Java with syntax, examples, and real-life use cases.

https://infitechx.com/final-keyword-in-java/

Hi all!

Topic - quick "review"

Today was a very very busy day I didn't have time to learn anything which is my mistake. Very tired, just did a quick simple calc on what I've learnt so far, which I aren't proud of at all (not pushing myself to my limits) , I know I could do better but extremely exhausted today. But that's how the journey goes, some bad days, some good days but all it matters is you bounce back and stay consistent. Anyways, always appreciate the feedback you guys have been great so far starting to pick up better habits.

Thanks!

Topic - Project!

Hi all!

For day 6 I made a battle game project. User can pick their and computers health, RNG damage but the "highest" damage can be only the current player/computer health to make it fair. Implemented some error handling to catch any incorrect inputs especially not entering a numeric value or entering a health of 0 or less. Had fun creating this project, at a point the logic was mega messy but I managed to clean it up by re writing that section. Sometimes I feel like just getting a pen and paper and writing it down helps you to re-write it much better. Is error handling used commonly for checking correct inputs? or is it better to do it "manually". If anyone feels like they have criticism then go for it! Always opened for feedback, been great hearing from you all thanks!

1. What is the difference between Hashmap and Hashtable?

2. Explain SOLID principles

3. Write a program to check for two-sum in O(n) time

4. Explain DI in Java springboot

For anyone attending interviews I hope this was helpful

One thing about Java😅

Hi everyone,

I’m planning to start learning Java from scratch in January 2026, but I want to do it properly this time.

Most of the Java courses I come across feel very similar: they move fast, focus on syntax, and stop at “how to use” things instead of explaining why they exist and how they actually work under the hood.

For example:

• Why is a String immutable in Java, and what really happens in memory when I create one?

• How does an Array actually work internally? What’s stored where?

• What’s going on in the JVM when objects are created, passed, or garbage-collected?

• How memory, references, stack vs heap, class loading, etc. really function — not just definitions, but real explanations.

I’m not looking for:

• Crash courses

• “Learn Java in 10 hours” content

• Courses that assume I just want to pass interviews as fast as possible

What I am looking for:

• A well-structured Java course or learning path

• Slow and detailed explanations

• Strong focus on fundamentals, internals, and mental models

• Ideally something that explains how Java thinks, not just how to write code

It can be a course, book, video series, university material, or even a combination of resources. I’m okay if it’s long or demanding — depth matters much more than speed for me.

If you’ve personally gone through something like this or know a resource that truly teaches Java from the inside out, I’d really appreciate your recommendations.

Thanks in advance.

Yesterday, I was working on a code that calculates the sum of a multiplication table. I got stuck for about 15–20 minutes because I couldn’t figure out the logic for the addition. Feeling frustrated, I took a pen and paper (as shown in the second image) and started jotting down my thoughts. The moment I simplified things on paper, the logic clicked instantly. Within the next 1–2 minutes, I fixed the code — and it worked perfectly!

Conclusion: Always keep things simple.

Now guys share us your cool experiences.

Your reply matters!

Hi everyone,

I’d like to introduce a new Java desktop toolkit, built from the ground up.

It includes dozens of components, accessibility support across three operating systems (Windows, macOS, and Linux), advanced language support, text direction, video, music, 3D, and charts.

The appearance is fully customizable (including dark themes), animations are native, and all the features you’d expect are there: printing, desktop integration, and testability.

I hope the community enjoys it. Although it is—admittedly—the product of AI, it was crafted with great care over the course of several months, ultimately saving tokens for anyone looking to build desktop applications.

https://limn-toolkit.github.io/limn-toolkit/

Enjoy

Ok so here’s the story : I’m currently a 6th sem BTech CSE student in India and I don’t have an internship lined up for Summer 2026.

Yeah… feels like I’m cooked

I’ve decided to go with Java development as my main path. So far I’ve done:

OOPS

Exception handling

Basics of DSA

Basic Java fundamentals

Now reality is hitting because I need an internship and I don’t see a very clear structured roadmap anywhere.

Everywhere I look...people are doing MERN. Makes me question if choosing Java was a mistake. Did I mess up by not going full stack JS?

Currently the path in my head is:

Finish Java Collections

Start Spring Boot

Parallel grind DSA

But I honestly don’t know if that’s the correct order or if I’m missing something major.

So , from the community i wanted to know :

*What is the exact step by step roadmap you’d recommend from here?

*What projects should I build to actually look internship-ready?

TLDR:

6th sem CSE student, no Summer 26 internship yet (feels like I’m cooked). Chose Java. Done OOPS, exceptions, basic DSA. Confused if Java was the right choice since everyone’s doing MERN. Current plan: Java Collections TO Spring Boot & DSA parallel.

Need:

*A clear step-by-step roadmap for Java backend

*Project suggestions that actually make me internship-ready

Everyone tells founders to move fast and break things with Node.js/Python/Go. I'm leading tech for a new fintech startup, and I deliberately chose Java 21 + Spring Boot. My reasoning is getting proven right every week: Hiring: I can find serious engineers. The pool is deep with people who understand systems, not just syntax.Speed: With Spring Initializr, Chat-GPT/Copilot for boilerplate, and Docker, our time to first feature was no slower. But our time to stable, monitored, scalable feature was 10x faster.The Moat: As we scale, the problems other stacks are desperately solving (concurrency, memory leaks, observability) are problems Java solved 15 years ago. Loom and Virtual Threads are just the latest superweapon. Are we the outliers? Or is the Java is slow for startups meme finally collapsing under the weight of modern tooling?

Discussion:

1. What would it take for you to advocate Java for a brand new, scrappy MVP?

2. Biggest legitimate downside for startups in 2024? Is it still the memory footprint/container size?

Hey everyone,

I’ve been trying to improve my Java Streams skills for interviews, but I keep getting stuck when questions involve anything beyond basic operations.

For simple problems using filter, map, etc., I’m okay. But when questions get slightly complex — like finding the first repeating character (involving things like LinkedHashMap or more advanced transformations) — I completely blank out.

In interviews, I often end up telling the interviewer that I’ll first write the logic using loops and then convert it into streams. But honestly, I struggle to even think in terms of streams afterward.

I think one of the reasons might be that I rely too much on AI tools and IDE suggestions while coding, so I don’t really internalize the available stream methods or patterns.

Has anyone faced something similar?

How did you train yourself to think in streams instead of falling back to loops?

Any tips, practice strategies, or resources would be really appreciated

Hey guys, today I couldn’t learn anything new because of a power cut in my area. But I still made some progress — I spent some time reading Java: The Complete Reference, which my course instructor recommended.

The book is pretty solid in terms of explanations, and I’m planning to go through it for more in-depth understanding.

My goal is to finish up to Chapter 7 before I move on to OOP. That’s all for today. Hopefully tomorrow is more productive. See you then.

I am getting the login form for register whereas not getting for kaka wth is thiss idont want login in register

☕ Java Versions Timeline — 1996 → 2026

From JDK 1.0 to Java 27, Java has continuously evolved while maintaining its “write once, run anywhere” philosophy.

📌 Key LTS releases: Java 8 → 11 → 17 → 21 → 25

🚀 Latest release: Java 27 — September 15, 2026

🔄 Java follows a 6-month release cycle, with LTS releases every 2 years.

Which Java version are you currently using? 👇