Is ByteByteGo Good Platform for System Design Interview? Review

ByteByteGo System Design Course Review: Should You Buy It?

Credit - ByteByteGo

Hello guys, if you are preparing for System Design Interview in 2025 then you may have most likely come across names like ByteByteGo, Alex Xu or System Design Interview - An Insider Guide by Alex Xu, and if you are wondering what they are or you know about them but thinking whether ByteByteGo is worth it or not for System Design and Coding interview preparation then you are not alone?

If you ask me, Yes, ByteByteGo is indeed worth considering for your System Design Interview preparation, because it was created by Alex Xu, an expert with FAANG interview experience and someone who has the privilege to be on both sides of the table.

10 Must Know Topics for System Design Interviews

Disclosure: This post includes affiliate links; I may receive compensation if you purchase products or services from the different links provided in this article.

system design template
image_credit - DesignGuru.io

Hello devs, if you have attended technical interviews, then you may know thatthe System Design part is one of the toughest to crack. I think, why so? And the answer I found was that most of the developers are not really familiar with essential System design topics or concepts, and that's what I am going to share in this article.

As I have said before, System design interviews are a crucial part of the hiring process for software engineers and developers, and you must prepare for them; leaving it to chance is not a good idea.

Difference between @Controller vs @RestController in Spring Boot

Hello friends, if you are preparing for Java and Spring Developer interview then you may have come across "difference between @Controller and @RestController annotation" in Spring Boot and Spring Framework in general. It's one of the popular spring question which I have also mentioned in my list of 25 Spring Framework questions earlier

6 Best Udemy Courses to Learn Agentic AI from Scratch in 2026

Top 6 Udemy Courses to Learn Agentic AI with Python
credit — Pault Iustzin of LLM Engineer’sHandbook

Hello guys, Agentic AI is quickly becoming one of the most important shifts in modern software development. Instead of single-prompt AI systems, we’re now building autonomous agents that can plan, reason, use tools, collaborate with other agents, and execute multi-step tasks reliably.

In 2026, knowing how to build AI agents with Python is no longer optional for AI engineers, backend developers, or full-stack engineers working with AI-driven products.

Kotlin or Java? Which is Best Programming Language for Android ?

best Kotlin courses

Ever since Google announced @Kotlin as the official language for Android development at Google IO in 2017, programmers who want to become Android developers are in a dilemma.

The big question in front of them is whether they should learn Kotlin or Java.

If you are a complete beginner who wants to learn Android development, then my answer is Java, but if you are a Java developer who wants to jump into the lucrative market of Android app development, then my answer is Kotlin.

I’ll discuss why beginner Android programmers should start with Java and why Java developers should learn Kotlin in this article.

When I say beginners should start with Java, you may be thinking, “What the heck? Kotlin is much more productive, less boilerplate code, and now the official language of Android development, and this guy is suggesting learning Java. I am not gonna fall for it…”

Well, being a Java developer, I may be a little bit biased, but I’ll try to explain the reasons why I suggest a beginner Android developer starting with Java rather than Kotlin.


Kotlin or Java? Which is better for Android Developers?

The first and foremost thing is that Android development is not everything; as a programmer, you may be starting your career with Android development, but if you start with a well-established language like Java, you become a part of the bigger Java community and market, which directly means more job opportunities.

The second and more important thing is that there is a huge community of Java programmers, which means you can find answers when you are stuck.

This is very important because, as a beginner, you will face a lot of technical problems and you might not know where to head when you are stuck.

When you search Google with a Java problem, you are bound to get answers; the same cannot be said for Kotlin, which is still a new programming language.

There are also more tutorials, books, and courses out there, both free and paid, which can teach you Android development with Java, like this list of Android resources for Java programmers, but there are not many for Kotlin, especially free resources on Android development.

Things will definitely improve over time when more and more programmers start using Kotlin, but I doubt it can ever touch the popularity and adoption of the Java programming language.

That’s why I suggest, a beginner programmer who wants to become an Android developer should start with Java, rather than Kotlin.

However, that’s not a hard and fast rule; if you prefer learning Kotlin rather than Java due to productivity reasons and are mostly focused on Android development, then you can sure start with Kotlin, and Kotlin: The Mega Course – All-in-One is a good place to begin.

But, once you know Java, your journey to Kotlin will also be easy and smooth because Kotlin is 100% interoperable with Java. It compiles into Java bytecode and runs on JVM.


Java Programmers Should Learn Kotlin

Now, coming back to the second set of programmers who wants to learn Android development: our fellow Java developers. For them, I think it's best to learn Kotlin because it really improves productivity.

A class that takes 50 lines of code in Java can really be written in just one line in Kotlin. It can help you avoid all boilerplate code, like you don’t need to specify getters and settersequals()hashCode()or toString() methods. Kotlin can generate all that by itself.

Here is a nice comparison between Kotlin and Java in terms of productivity and lines of code to write similar stuff:

If you don’t know, Kotlin was developed by JetBrains, the company behind one of the most popular Java IDEs, IntelliJ IDEA. They were a Java shop and developing IDEs like IntelliJ IDEA, PyCharm, and ReSharper, all in Java, and built Kotlin to improve their productivity, but at the same time, they cannot rewrite all their code in Kotlin, so that’s why they made Kotlin fully interoperable with Java.

Because Kotlin generates Java bytecode, you can use your favorite Java frameworks and libraries in Kotlin and your Java friends can also use any Kotlin framework you develop.

Even a major Java framework like Spring has started supporting Kotlin from Spring 5. If you don’t know Spring and want to learn Spring Boot 4, Spring 7 & Hibernate for Beginners, check that out.

Even though currently, almost all @android code, examples, and apps are in Java, it will change in the future because Google has declared Kotlin as the official language for Android app development.

Many companies have already started using Kotlin for their Android app development, and that’s the main reason I think Java developers should learn Kotlin.

If you decide to learn Kotlin Programming language, then Kotlin for Android: Beginner to Advanced is also a great place, to begin with. It’s a no-nonsense course for Java developers which will help you to get going with Kotlin in no time.

You don’t need to start with things like what a variable and object are, as this course has the right pace and depth for Java developers as compared to other beginner Kotlin courses for Android development.

If you prefer books, then Kotlin in Action is also not bad. You can learn about all the essential features of Kotlin, e.g. var vs val, data keyword, and functional programming all by yourself.

That’s all about whether Android developers should learn Kotlin or Java. As I said, if you are a complete beginner who wants to start your career as an Android developer, you’d better start with Java.

You will not only get up to speed in no time, but you would have better community support, and knowledge of Java will help you a lot in the future. It will also help you to learn Kotlin in the future.

If you are a Java developer, then you’d better start learning Kotlin to not only improve your productivity but also help you become part of a lucrative niche of Java developers who know Kotlin, which may give you a competitive edge in the job market. It’s also one of the 3 JVM languages Java developer should learn on my list.

Other  Programming Courses and Articles you may like

Thanks for reading this article so far. If you liked it then, please share them with your friends and colleagues. If you have any questions or feedback, then please drop a note.

P. S. - If you want to learn a valuable skill like Kotlin, then I highly recommend you check out these best Kotlin courses from Udemy, which are both comprehensive and very engaging. You can use this course to learn Kotlin for server-side Java development and mobile app development with the Android platform.

    Top 35 Java Interview Questions for 1 to 3 Years Experienced Developers

    Here is the list of some useful Java interview questions for experienced Java programmers having experience in range of 2 to 5 years. As an experienced developer you are expected to learn about OOP concepts, Java basics, Java Collection framework, Multi-threading and Concurrency utilities introduced in Java 5 and 6, Debugging Java application, Algorithm and Data structure, Some questions on design patterns, JVM and Garbage collection and couple of puzzles.

    Actually its mix of everything you do in your day to day work.

    If you are going for Java developer with some exposure on web development you will also be asked about popular Java frameworks like Spring, Hibernate, Struts 2.0 and others.

    If you have more than 5 years of experience you can also expect questions about build tools like Maven, ANT and Gradle, Java best practices, Unit testing and JUnit and your experience about solving production issues.

    One of the most common question I have faced is talking about the last production problem you have faced and how did you solved it. If you are asked same question, give them step by step detail, right from analyzing problem to tactical fix to strategic solution.

    In this article, I am going to share my list of Java Interview questions for Java guys having 2 to 5 years of experience. Since I had similar experience couple of year ago, I know what questions are asked and keeping a list for your own always helps when you start looking for new challenge in your career.

    I am not providing answers of these question in this post due to two reasons, questions are quite simple and you guys probably know the answer, second providing answer means I cannot use this post for my own preparation later, which is more important.

    Though, I could write another article answering all these question if anyone request or I feel people need it.

    By the way, if you are new to Java programming language or want to improve Java skills then you can also checkout following best Java courses to get better:

    1. The Complete Java Masterclass (covers Java 17)
    2. Java Programming and Software Engineering Fundamentals Specialization Certificate on Coursera
    3. Java Programming Bootcamp: Zero to Mastery
    4. The Complete Java Programming Masterclass! [Karpado]
    5. CodeGym (learn Java by building Games)

    These are my favorite online courses and platforms to learn Java from scratch and also build your Java skills. If you need more advanced courses to take your Java skill to next level you can also see following articles:

    And, If you like my post, consider subscribing to my newsletter, its FREE and you will not miss any of my post

    35 Java Interview Questions for 1 to 2 years Experienced

    This list contains questions from different topics e.g. OOP concepts, multi-threading and concurrency, Java collections, Web services, Spring, Hibernate, Database and JDBC, it doesn’t cover all topics you need to prepare.

    I will add few more topics later when I have some time, for now, try to answer these questions without doing Google :)

    1. Java Interview questions on OOP Concepts

    1. What is difference between loose coupling and tight coupling?
    2. What is difference between cohesion and coupling?
    3. What is Liskov Substitution principle? Can you explain with example?
    4. What is difference between abstract class and interface in Java?
    5. What is difference between composition, aggregation and association?

    2. Java Interview questions on Collections

    1. Difference between List, Set and Map in Java?
    2. Difference between synchronized and concurrent collection in Java?
    3. How get method of HashMap works in Java?
    4. How ConcurrentHashMap is different than Hashtable? How it achieve thread-safety?
    5. When to use LinkedList over ArrayList in Java?

    3. Java Interview questions on Concurrency

    1. How notify and notifyAll work, and the difference between them. Why prefer notifyAll to notify?
    2. What is a race condition and how do you avoid it?
    3. What is a deadlock and how do you avoid it?
    4. What are some of the high-level concurrency classes provided by java.util.concurrent and how do they work?
    5. Can you implement producer consumer solution in Java?

    4. Java Interview questions on Database

    1. How do you prevent SQL injection attacks?
    2. What is difference between WHERE and HAVING clause?
    3. What are transactions? What is ACID?
    4. Difference between truncate, delete and drop clause in SQL?
    5. What are window functions? how they work?

    5. Java Interview questions on Hibernate

    1. When is it better to use plain SQL instead of ORM?
    2. Difference between sorted and ordered collection?
    3. How second level cache works?
    4. What is difference between save() and persist()?
    5. What is difference between Hibernate and MyBatis?

    6. Java Interview questions on Web Services and Microservices

    1. What is the difference between SOAP-based web services and REST-based web services?
    2. What is SOAP Envelope?
    3. How to implement security in RESTful web service?
    4. What is Payload in REST?
    5. What is Microservices?
    6. What is difference between Microservices and REST?
    7. What is difference between Monolithic and Microservices?
      hint — development, one vs many, latency, deployment
    8. What problem does SAGA pattern solve?
      hint — distributed transactions
    9. What is service discovery in Microservices?
    10. What are common Microservices Pattern you have used in your project?

    Java and Spring Interview Preparation Material

    Before any Java and Spring Developer interview, I always use to read the below resources

    Grokking the Java Interviewclick here

    I have personally bought these books to speed up my preparation.

    You can get your sample copy here, check the content of it and go for it

    Grokking the Java Interview [Free Sample Copy]: click here

    If you want to prepare for the Spring Boot interview you follow this consolidated eBook, it also contains microservice questions from spring boot interviews.

    Grokking the Spring Boot Interview

    You can get your copy here — Grokking the Spring Boot Interview

    Thank you guys for now. You can find the answers in web easily but if there are enough interest, I can also update the post. Let me know if you have also asked these questions before. If anyone knows answer, can also post as comment.

    Good luck for your Java Interview.

    By the way, if you are new to Java programming language or want to improve Java skills then you can also checkout following best Java courses to get better:

    1. The Complete Java Masterclass (covers Java 17)
    2. Java Programming and Software Engineering Fundamentals Specialization Certificate on Coursera
    3. Java Programming Bootcamp: Zero to Mastery
    4. The Complete Java Programming Masterclass! [Karpado]
    5. CodeGym (learn Java by building Games)

    These are my favorite online courses and platforms to learn Java from scratch and also build your Java skills. If you need more advanced courses to take your Java skill to next level you can also see following articles:

    Other Microservices and Java articles you may like

    And, If you like my post, consider subscribing to my newsletter, its FREE and you will not miss any of my post