Senior Java Backend Developer (Java / Spring Boot / Microservices / Kafka) - calgary

Cogency (Calgary AB, Canada) Follow 2 days ago

Overview

Cogency Inc. is seeking a highly skilled Senior Java Backend Developer to build and maintain scalable, high-performance enterprise applications. The ideal candidate will have deep expertise in Java, Spring Boot, microservices architecture, and Kafka-based event-driven systems, with a strong focus on backend development, system design, performance optimization, and distributed systems integration.

Key Responsibilities

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

Required Technical Skills

Core Java
- Strong understanding of Object-Oriented Programming (OOP)
- Expertise in Collections and Exception Handling
- Hands-on experience with Java 8+ (Streams, Lambdas)
- Knowledge of Design Patterns
- Understanding of JVM internals and Garbage Collection
- Robust knowledge of multithreading and concurrency
Spring Boot & Backend Frameworks
- Dependency Injection (DI) and Inversion of Control (IoC)
- REST API development and best practices
- Configuration and environment management
- JPA / Hibernate for persistence
- Transaction management
- Unit and integration testing (JUnit, Mockito)
Microservices Architecture
- Service decomposition and domain-driven design (DDD)
- Inter-service communication (REST, messaging)
- Resilience patterns (Circuit Breaker, Retry, Bulkhead)
- Observability (logging, monitoring, distributed tracing)
- API gateway and service discovery
Kafka & Event Streaming
- Kafka topics, producers, and consumers
- Consumer groups and offset management
- Kafka cluster architecture and replication
- Message serialization (Avro / JSON)
- Monitoring, troubleshooting, and performance tuning
Database & Performance
- Strong SQL skills and query optimization
- Experience with relational databases (Oracle, SQL Server, PostgreSQL)
- Knowledge of indexing and performance tuning