Senior Java Developer

Global Financial Firm located in MISSISSAUGA, ON has an immediate contract opportunity for an experienced Senior Java Developer

Pay Rate: $70.00 - $75.00 Negotiable based upon years of experience

Work Mode: Hybrid

Location: Mississauga, ON

Responsibilities:

• Analyze complex business requirements and translate them into highly scalable, reliable, and secure backend systems designs.
• Write high-quality, production-ready, and performant Java code using advanced software engineering principles.
• Lead the technical implementation and delivery of critical, complex backend and data-processing initiatives.
• Act as the resident Subject Matter Expert (SME) in high-throughput data processing and JVM performance tuning.
• Diagnose, profile, and resolve complex performance bottlenecks, memory leaks, and concurrency issues in high-volume distributed environments.
• Champion code quality through Test-Driven Development (TDD), comprehensive unit/integration testing, and rigid code review standards.
• Provide technical mentorship and architectural guidance to other engineers on the team.

Requirements:

• Minimum 8 years of professional experience in application development or systems analysis, with a heavy emphasis on Java-based backend architectures.
• Deep, expert-level understanding of Core Java (Java 11/17/21), including advanced multithreading, concurrency models, Java memory model, and Collections API.
• Extensive hands-on experience building distributed data processing systems, ETL pipelines, and real-time streaming architectures using tools like Apache Kafka, Apache Spark, Flink, or Hadoop.
• Strong experience with the Spring Ecosystem (Spring Boot, Spring Cloud, Spring Data, Spring Security) and ORM frameworks (Hibernate/JPA).
• Proficiency in designing schemas and writing optimized queries for both relational databases and NoSQL stores.
• Comprehensive understanding of distributed system design patterns, consensus protocols, caching strategies, and API design.
• Practical experience with containerization, continuous integration/continuous deployment tools, and infrastructure-as-code principles.
• Strong advocate for testing frameworks such as JUnit, Mockito, and integration testing tools.

Preferred Skills:

• Experience with cloud platforms (AWS, Azure, or GCP), specifically managed database and container services.
• Experience in financial services, banking technology, or large-scale enterprise transaction systems.
• Familiarity with Unix/Linux environments, shell scripting, and network configurations.

This role is for an existing vacancy.