Lenovo Java Backend Developer Interview Experience (3 YOE) – Complete Question Breakdown
- Experience
- 3 years
- Posted
- 28 Feb 2026
Summary
I recently appeared for a Backend Developer interview at Lenovo, where I was asked questions spanning Java core concepts, Microservices, System Design, Spring Boot, SQL, Git, and coding problems using the Stream API.
How it went
Recently, I appeared for a Backend Developer interview at Lenovo (Tech Stack: Java, Spring Boot, Microservices, MySQL, Apache Kafka, DSA). I’m sharing my experience and some of the questions that were asked — hoping it helps others preparing for similar roles.
Questions asked (37)
- 01
Java 8 New Features
Other
What are the new features introduced in Java 8?
- 02
What is a Method Reference?
Other
What is a Method Reference?
- 03
Default Methods in Interfaces
Other
What are Default Methods in interfaces?
- 04
Intermediate Operations in Streams
Other
Explain Intermediate Operations in Streams.
- 05
HTTP Status Code 204
Other
What is HTTP Status Code 204?
- 06
HashMap vs Hashtable
Other
Difference between HashMap and Hashtable.
- 07
Garbage Collection
Other
What is Garbage Collection and how does it work?
- 08
How JWT Works
Other
How does JWT (JSON Web Token) work?
- 09
Integrating 3rd-Party APIs
Other
How do you integrate 3rd-party APIs in your project?
- 10
Microservices Concept
System Design
Explain the concept of Microservices in your project.
- 11
Authentication Layer in Architecture
System Design
Explain the Authentication Layer in your architecture.
- 12
Distributed Transactions: 2PC vs Saga
System Design
Distributed transactions – Compare 2PC vs Saga (real production trade-offs).
- 13
Debugging Duplicate Payment Transactions
System Design
Debugging duplicate payment transactions issue end-to-end.
- 14
Design a Rate Limiter
System Design · Hard
Design a rate limiter handling millions of requests per second.
- 15
Architect a Real-time Fraud Detection System
System Design · Hard
Architect a real-time fraud detection system.
- 16
Spring Boot Application Startup Process
Other
What happens internally when a Spring Boot application starts? (Lifecycle & Bean Initialization Flow)
- 17
What is @Lazy?
Other
What is @Lazy?
- 18
What is @Component?
Other
What is @Component?
- 19
What is Component Scanning?
Other
What is Component Scanning?
- 20
Global Exception Handling in Spring Boot
Other
How do you handle exceptions globally?
- 21
What is JPA?
Other
What is JPA?
- 22
Explain Bean Scopes
Other
Explain Bean Scopes.
- 23
@RequestParam vs @RequestBody
Other
@RequestParam vs @RequestBody
- 24
What is @PathVariable?
Other
What is @PathVariable?
- 25
Saga & Circuit Breaker Design Pattern
System Design
Saga & Circuit Breaker Design Pattern
- 26
SQL: Fetch Records with Offset and Limit
Data Structures & Algorithms · Easy
Given a User table with 50 records, write a SQL query to fetch 20 records starting from the 5th row, including only the first and last name.
- 27
SQL: INNER JOIN Query
Data Structures & Algorithms · Easy
Write an INNER JOIN query between two tables.
- 28
Git Usage in Team
Other
How do you use Git in your team?
- 29
Git Branching & Merging Strategy
Other
Branching & merging strategy?
- 30
JUnit and Mockito Usage
Other
What is the use of JUnit and Mockito in your project?
- 31
Calculate Total Revenue using Streams
Data Structures & Algorithms · Easy
Calculate total revenue from all orders using Streams.
- 32
Find Top 3 Highest-Priced Products using Streams
Data Structures & Algorithms · Medium
Find the Top 3 highest-priced products across all orders.
- 33
Group Products by Category and Calculate Total Revenue
Data Structures & Algorithms · Medium
Group products by category and calculate total revenue per category using Streams.
- 34
Find Customers with More Than 3 Orders
Data Structures & Algorithms · Medium
Find customers who placed more than 3 orders using Streams.
- 35
Identify Most Frequently Sold Product
Data Structures & Algorithms · Medium
Identify the most frequently sold product using Streams.
- 36
Anagram Check
Data Structures & Algorithms · Easy
Determine if two strings are anagrams of each other.
- 37
Product of Array Except Self
Data Structures & Algorithms · Medium
Given an integer array nums, return an array answer such that answer[i] is equal to the product of all the elements of nums except nums[i]. The product of any prefix or suffix of nums is guaranteed to fit in a 32-bit integer. You must write an algorithm that runs in O(n) time and without using the division operation.