Java 8 vs Java 11 vs Java 17 – What's Best for Backend Interviews

byAvinash May 21, 2025

Java 8 vs Java 11 vs Java 17 – What's Best for Backend Interviews?




If you're preparing for backend developer interviews in 2025, one common question is:
"Which Java version should I focus on – Java 8, Java 11, or Java 17?"

In this post, we'll break down the major features, compare these versions, and guide you on which one to prioritize.

1. What are Java 8, 11, and 17, and why are they important?

Java 8, Java 11, and Java 17 are Long-Term Support (LTS) versions. LTS versions are stable, enterprise-ready, and widely used in production environments. That’s why most companies expect candidates to be familiar with these.

  • Java 8 (Released 2014)

  • Java 11 (Released 2018)

  • Java 17 (Released 2021)

Most companies avoid intermediate versions like Java 9, 10, 12, etc., because they are short-term and not supported long enough for enterprise use.

2. Key Features in Java 8

Java 8 brought a massive change in how Java is written and is still the most asked version in interviews:

  • Lambda Expressions: Enable functional-style programming in Java.

  • Stream API: Helps in processing collections (filter, map, reduce).

  • Functional Interfaces: Like Runnable, Predicate, Function — often used with lambdas.

  • Optional Class: Avoid NullPointerException with elegant null handling.

  • New Date and Time API: Better than old Date class, using LocalDate, LocalDateTime.

Common Interview Questions:

  • What is the difference between map() and flatMap()?

  • How does filter() work in streams?

  • What is the benefit of Optional?

3. Key Features in Java 11

Java 11 added several small but useful improvements, especially for backend developers using modern tools and frameworks like Spring Boot.

  • var Keyword: Local variable type inference – cleaner code.

  • New String Methods:

    • isBlank() – checks if a string is empty or just whitespace.

    • lines() – splits a string into lines.

    • strip(), stripLeading(), stripTrailing() – better than trim().

  • New HTTP Client API: A modern alternative to HttpURLConnection, supports async calls.

  • Removed Old Modules: JavaFX, CORBA, etc., are no longer part of JDK.

Common Interview Questions:

  • How is var different from Object?

  • Explain usage of new String methods.

  • When to use the new HTTP Client?

4. Key Features in Java 17

Java 17 is the latest LTS version and is increasingly adopted in modern enterprise apps and Spring Boot 3.x projects.

  • Sealed Classes: Control which classes can extend a class.

  • Pattern Matching for instanceof: Simplifies type checks.

  • Switch Expressions: Return values from switch blocks.

  • Text Blocks: Multiline string support using """.

  • Record Classes: Simplified immutable data classes.

Common Interview Questions:

  • What is the use of sealed classes?

  • How are records different from POJOs?

  • Give an example of a switch expression.

5. Performance and Tooling

Java 11 and 17 offer better performance and memory usage compared to Java 8. Most modern cloud-native applications and containers (like Docker) work better with Java 11+.

Build tools and frameworks like:

  • Spring Boot 3.x requires Java 17.

  • Micronaut, Quarkus, and other modern frameworks are optimized for newer Java versions.

6. Which version should you focus on for interviews?

Here’s what most backend interviews in 2025 expect:

  • Java 8: Must-know! Focus on Stream API, Lambdas, Functional Interfaces, and DateTime.

  • Java 11: Good to know! Especially for Spring Boot-based applications and microservices.

  • Java 17: Bonus! Useful for product companies or advanced roles.

7. Pro Tip for Interviews

Mention in your resume:

"Proficient in Java 8 and Java 11, with working knowledge of Java 17."

It shows that you're confident with the widely used versions and are also aware of the latest developments.

8. Conclusion

If you're starting now, master Java 8 concepts deeply. Then gradually learn the additions in Java 11 and Java 17.

In real interviews, most coding questions and project discussions will be around Java 8 and 11. Java 17 is more useful for product-based companies and cutting-edge tech stacks.

✅ Start with Java 8 → Move to Java 11 → Explore Java 17

Keep practicing real interview questions and stay updated with frameworks like Spring Boot. Follow InterviewYatra.com for more backend interview posts!

Java 8 vs Java 11 vs Java 17 – What's Best for Backend Interviews?

Java 8 vs Java 11 vs Java 17 – What's Best for Backend Interviews?

If you're preparing for backend developer interviews, one common confusion is: Which Java version should I focus on – Java 8, Java 11, or Java 17? In this post, we'll break down the major differences, highlight key features, and guide you on what interviewers expect in 2025.

📌 Note: Java 8, 11, and 17 are all LTS (Long Term Support) versions, meaning companies use them widely in production.

🔥 Quick Comparison Table

Feature Java 8 Java 11 Java 17
Release Year 2014 2018 2021
LTS ✅ Yes ✅ Yes ✅ Yes
var keyword ❌ Not available ✅ Introduced ✅ Available
New HTTP Client API ❌ ✅ ✅
Pattern Matching ❌ ❌ ✅
Switch Expressions ❌ ❌ ✅

💡 Key Features in Each Version

🟢 Java 8 (Most Common in Interviews)

  • Lambda Expressions
  • Streams API
  • Functional Interfaces
  • Optional Class
  • New Date and Time API

Most companies still ask questions based on Java 8 because it brought major changes in programming style.

🟠 Java 11 (Production Ready + Modern)

  • Local variable type inference using var
  • Improved String methods (e.g., isBlank(), lines())
  • New HTTP Client API
  • Removed deprecated modules

Java 11 is widely used in enterprise projects post Java 8.

🔵 Java 17 (Future-Proof + Advanced)

  • Sealed Classes
  • Pattern Matching for instanceof
  • Switch Expressions
  • Text Blocks for multiline strings
  • Record Classes (Immutable data classes)

Good to know, but not mandatory unless applying at product-based companies using the latest tech stack.

✅ Which Version Should You Prepare For Interviews?

  • Java 8 – Mandatory: Most backend interviews test Lambda, Stream API, Optional, and DateTime.
  • Java 11 – Recommended: Especially if the company uses microservices or Spring Boot 2.x+
  • Java 17 – Bonus: For product companies (like Google, Netflix, etc.) or projects on Spring Boot 3.x+
👨‍💻 Pro Tip: Mention in your resume that you’re comfortable with Java 8, 11, and exploring Java 17 features.

📌 Conclusion

For backend developer interviews, always be strong in Java 8. Learn the improvements in Java 11, and optionally explore Java 17 to stand out.

Keep preparing, keep coding – and follow InterviewYatra.com for regular interview questions, project-based insights, and resume tips!

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