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

Job Title: Senior Java Backend Developer (Java / Spring Boot / Microservices / Kafka) Company: Cogency Inc.

Location: Calgary (Hybrid – 3 Days Onsite, Downtown – Mandatory) Job Type: Full-Time Job Summary

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

Strong 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

Qualifications

Bachelor’s degree in Computer Science, Engineering, or 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 Work Model

Hybrid – 3 days per week onsite (mandatory) in downtown Calgary