Java Backend Specialist

Core Technical Skills

Evaluate the candidate's depth in:

• Core Java (Java 8/11/17+ features)


• Spring Boot and Spring ecosystem


• Microservices architecture


• REST APIs, messaging (Kafka/RabbitMQ), and event-driven architecture


• SQL/NoSQL databases and data modelling


• Cloud platforms (AWS/Azure/GCP) and containerization (Docker/Kubernetes)

Deep Java Assessment

Validate strong understanding of:

• Concurrency & Multithreading
  
  
  
  • Thread lifecycle, synchronization, locks, Executors, Completable Future
  
  
  • Concurrent Collections and thread-safe programming
  
  
  • Race conditions, deadlocks, and their mitigation
  
  
  
  


• Performance & Optimization
  
  
  
  • JVM memory model, heap/non-heap memory
  
  
  • Garbage Collection concepts and tuning basics
  
  
  • Profiling, memory leaks, CPU optimization
  
  
  • Performance bottleneck identification and resolution
  
  
  
  


• Time & Space Complexity
  
  
  
  • Analyse algorithm complexity (Big O notation)
  
  
  • Selection of appropriate data structures
  
  
  • Optimizing code for scalability and efficiency
  
  
  
  


• Collections & Java Internals
  
  
  
  • Internal working of HashMap, Concurrent HashMap, HashSet
  
  
  • equals() vs hash Code()
  
  
  • String, StringBuilder, String Buffer
  
  
  • Serialization and Java memory management
  
  
  
  


• Design Principles
  
  
  
  • SOLID principles
  
  
  • Design patterns (Factory, Strategy, Singleton, Observer, etc.)
  
  
  • Clean Code and best practices
  
  
  
  

Architecture & System Design Understanding

Assess the candidate's ability to understand:

• Design scalable, resilient, and secure enterprise applications


• Define microservice boundaries and communication patterns


• Handle scalability, high availability, and fault tolerance


• Apply caching, messaging, asynchronous processing, and resiliency patterns


• Make architecture and technology decisions with clear trade-offs

Technical Leadership

Evaluate whether the candidate can:

• Lead technical discussions and design reviews


• Mentor and guide development teams


• Review code and enforce engineering best practices


• Drive technical decision-making and resolve complex production issues


• Collaborate effectively with architects, product owners, and business stakeholders

Interview Focus

• Prioritize architecture, deep Java expertise, system design, performance optimization, and technical leadership over coding alone.


• Look for candidates who can own end-to-end solution design, troubleshoot complex issues, and lead technical initiatives.