Senior Java Backend Developer

Job Title:
Senior Java Backend Developer (Java / Spring Boot / Microservices / Kafka)

Work Location: Client – 3 days onsite per week (mandatory) downtown Calgary

Company: Cogency

Job Summary

We are seeking a Senior Java Backend Developer with strong expertise in building scalable, high-performance enterprise applications. The ideal candidate will have deep hands-on experience in Java, Spring Boot, microservices architecture, and Kafka-based event-driven systems. This role focuses primarily on backend development, system design, performance optimization, and integration within a distributed environment.

Key Responsibilities

• Design, develop, and maintain robust backend services using Java and Spring Boot
• Develop and maintain RESTful APIs and microservices-based solutions
• Build and support event-driven architectures using Kafka
• Participate in architecture discussions and contribute to technical design decisions
• Implement resilience, fault tolerance, and scalability best practices
• Optimize application performance, memory usage, and database interactions
• Write clean, maintainable, and well-documented code following coding standards
• Perform unit testing, integration testing, and support QA/UAT cycles
• Monitor, troubleshoot, and resolve production issues
• Collaborate with Dev Ops, frontend teams, business analysts, and other stakeholders

Required Technical Skills

Core Java

• Strong understanding of Object-Oriented Programming (OOP) principles
• In-depth knowledge of Collections and Exception Handling
• Hands-on experience with Java 8 features (Streams, Lambdas)
• Solid understanding of Design Patterns
• Knowledge of Garbage Collection and JVM memory management
• Multithreading and concurrency concepts

Spring Boot & Backend Frameworks

• Dependency Injection (DI) and Inversion of Control (IoC)
• REST API development and best practices
• Configuration management and environment handling
• Unit and integration testing (JUnit, Mockito)
• Service decomposition and domain-driven design principles
• Inter-service communication (REST, messaging)
• Resilience patterns (Circuit Breaker, Retry, Bulkhead)
• Logging, monitoring, and distributed tracing (Observability)
• API gateway and service discovery concepts

Kafka

• Topics, Producers, and Consumers implementation
• Consumer Groups and offset management
• Kafka cluster architecture and replication
• Kafka monitoring, troubleshooting, and performance tuning

Database & Performance

• Strong SQL skills and query optimization
• Experience with relational databases (e.g., Oracle, SQL Server, Postgre
  
  SQL)
• Understanding of indexing and performance tuning

Qualifications

• Bachelor’s degree in Computer Science, Engineering, or a related field
• 7+ years of hands-on backend development experience
• Experience working in large-scale enterprise environments
• Strong analytical, problem-solving, and debugging skills
• Excellent communication and collaboration abilities