Virtusa expected

1. Java 17-21 Questions¶

Java Features¶

What new features in Java 17/21 have you used in production?
Explain Records. When would you use them?
Difference between Record and Lombok DTO?
What are Sealed Classes?
Explain Virtual Threads in Java 21.
How do Virtual Threads differ from Platform Threads?
When should Virtual Threads not be used?

Concurrency¶

Difference between synchronized, ReentrantLock, and ReadWriteLock.
How ConcurrentHashMap works internally?
Explain CAS (Compare And Swap).
What is ThreadLocal?
Deadlock detection and prevention?

JVM¶

Explain Heap, Stack, Metaspace.
How does G1GC work?
What causes OutOfMemoryError?
How would you investigate memory leaks in production?

2. Spring Boot 3.x & Microservices¶

Spring Boot¶

What changed in Spring Boot 3?
Why was javax changed to jakarta?
Explain Bean lifecycle.
Difference between @Component, @Service, @Repository.
How does dependency injection work internally?

Security¶

JWT authentication flow?
OAuth2 vs JWT?
How would you secure microservice-to-microservice communication?

Database¶

Difference between JPA save() and saveAndFlush().
N+1 query problem?
How do you optimize Hibernate queries?

Transactions¶

How does @Transactional work internally?
Why doesn't @Transactional work in self-invocation?
What propagation levels have you used?

3. Microservices Architecture¶

Core Concepts¶

Why microservices instead of monolith?
What challenges arise after splitting a monolith?
How do services communicate?

Resilience¶

Circuit Breaker pattern?
Retry pattern?
Bulkhead pattern?
Rate Limiting?

Distributed Transactions¶

Very common question.

Question: You have Order Service and Payment Service. Payment succeeds but Order update fails. How will you handle it?

Expected discussion:

Saga Pattern
Choreography
Orchestration
Compensation transactions

Event Driven¶

Kafka vs RabbitMQ?
At-least-once vs Exactly-once delivery?
Consumer group?
Partitioning strategy?
How would you handle duplicate messages?

4. System Design Questions¶

Since you have 8+ years experience, expect these.

Design URL Shortener¶

Questions:

DB schema?
Generate unique short code?
Handle 100M URLs?
Cache strategy?
Analytics collection?

Design Payment System¶

Idempotency
Double payment prevention
Transaction tracking

Design Notification Service¶

Email
SMS
Push
Retry strategy

Design Search Service¶

Relevant because they specifically mention OpenSearch.

Questions:

How would you build product search?
How would you sync DB → OpenSearch?
Event-driven indexing?
Reindexing strategy?

5. OpenSearch / Elasticsearch¶

This is likely a differentiator for this role.

Basics¶

Difference between OpenSearch and Elasticsearch?
What is an inverted index?
What is a shard?
What is a replica?

Search¶

Full-text search vs keyword search?
Match query vs term query?
Fuzzy search?
Autocomplete implementation?

Scaling¶

What happens when a shard becomes too large?
How do you perform reindexing with zero downtime?

Real World¶

Question: A user updates product information in MySQL. How does it appear in OpenSearch?

Expected answer:

MySQL
  ↓
Outbox/Event
  ↓
Kafka
  ↓
Indexer Service
  ↓
OpenSearch

6. React 18 + TypeScript + Vite¶

React¶

Explain React rendering lifecycle.
Difference between useEffect and useLayoutEffect.
Why React Fiber?
What is Concurrent Rendering?
React 18 improvements?

Performance¶

React.memo
useMemo
useCallback

When to use each?

State Management¶

Redux vs Context API?
React Query vs Redux?
How do you manage server state?

TypeScript¶

interface vs type
generics
utility types
discriminated unions

Example:

type Success = {
    status: "success";
    data: User;
};

type Error = {
    status: "error";
    message: string;
};

Why is this useful?

7. Database Questions¶

SQL¶

Find second highest salary.
Window functions?
Explain indexing.
Clustered vs non-clustered index.

Scaling¶

Read replicas?
Sharding?
Partitioning?

NoSQL¶

MongoDB vs PostgreSQL?
When would you choose NoSQL?

8. Cloud Questions¶

AWS/GCP¶

How would you deploy microservices?
ECS vs Kubernetes?
Blue-Green deployment?
Rolling deployment?

Kubernetes¶

Since you've worked with OCI/K3s:

Difference between Deployment and StatefulSet.
How Service discovery works?
What happens when a Pod dies?
Ingress vs LoadBalancer?
ConfigMap vs Secret?

9. Architecture Ownership Questions¶

These are very common for senior candidates.

Example Questions¶

Describe a system you designed from scratch.
Biggest production incident you handled?
How did you reduce system latency?
How did you scale a service?
How do you review design documents?
How do you estimate technical risk?

Leadership¶

You led 10 developers, so expect:

How do you handle disagreements in design reviews?
How do you mentor junior engineers?
Tell me about a difficult stakeholder.
How do you balance speed vs quality?

10. Questions I Would Expect Specifically For You¶

Based on your background in payment disputes, React, Spring Boot, Kafka, Kubernetes:

Scenario 1¶

Design a dispute management system processing 1 million disputes/day.

Scenario 2¶

Design search for 50 million transactions using OpenSearch.

Scenario 3¶

Order service calls:

Inventory
Payment
Shipping
Notification

One service fails.

How do you ensure consistency?

Scenario 4¶

React page loads in 8 seconds.

How would you diagnose and optimize it?

Scenario 5¶

OpenSearch cluster latency suddenly increases from 50ms to 2s.

How would you investigate?

If this is a 60-90 minute senior engineer interview, I'd expect roughly:

20% Java/Spring
20% React/TypeScript
30% System Design
20% Microservices/Kafka/OpenSearch
10% Leadership & Ownership

The highest-leverage preparation areas are Saga pattern, Kafka internals, OpenSearch indexing/search design, React performance optimization, and end-to-end system design, because those are the topics that most clearly distinguish a senior engineer from a mid-level developer.