Java Software Engineer Contract Jobs in Ottawa, ON

Build bold. Deliver impact. Win together.

At General Dynamics Mission Systems–Canada, we’re not just engineering technology — we’re shaping the future of defence and security. Our teams design and deliver advanced, mission-critical solutions that enhance national security, strengthen communities, and protect the people we serve.

If you’re looking for meaningful work that contributes to a safer, more secure world, you’ll find purpose here. Every day, your skills will directly impact programs that matter.

Position Description

The LC4ISR ISTAR team is seeking a working level Software Engineer to support delivery of critical capabilities for the Canadian Army.  You will be working with a multidisciplinary engineering team to deliver Intelligence, Reconnaissance, Target Acquisition and Surveillance capabilities into a fully integrated tactical network, capable of providing flexible, multi-role and combat-capable communications, command and control.

You will be part of an agile development team, responsible for designing, implementing and verifying software components for ISTAR commanders and operators.  This role requires on-site work at our Ottawa office and customer locations within the National Capital Region, with flexibility to work remotely when necessary. Occasional travel may be required to support customer field trials.

Responsibilities

• Contribute to SDK design: define clean interfaces, document contracts, and ensure third-party integrators can consume your APIs predictably
• Build and maintain J2EE enterprise data sharing pipelines that move sensor-dervied and human reported intelligence across organizational and coalition boundaries
• Develop and maintain rich Java desktop client applications that consume and present sensor-derived and human-reported data sources
• Write clean, testable, maintainable code against established coding standards — and enforce those standards in peer code reviews
• Integrate communication protocols and message exchange patterns (ZeroMQ, REST, protobuf, JSON) between sensors and command-and-control subsystems
• Participate in all Agile processes: sprint planning, backlog refinement, stand-ups, reviews, and retrospectives
• Develop and execute unit, integration, and system-level tests; support customer field trials and verification events
• Identify, document, and resolve defects across the full product lifecycle
• Provide technical mentorship to junior team members.

What You Need to Have to Succeed

• Must have a technical Bachelor’s degree in Computer Science, Software Engineering, or an equivalent related field.
• 5–8 years of professional software development experience, with a majority in Java (Java 8+; Java 17 preferred)
• Demonstrated experience building desktop or embedded Java applications (not exclusively web/microservices)
• Solid command of Java 2EE/Jakarta EE fundamentals: lifecycle management, dependency injection, concurrency, and JMS or equivalent messaging
• Practical experience with MVVM or MVC in a Java desktop context (JavaFX, Swing, or equivalent)
• Candidates with a Spring Framework or Java MVC background are considered provided they can demonstrate depth in backend class decomposition, layered architecture design, and domain modelling
• Experience designing or consuming SDKs or integration APIs, able to reason about interface stability, versioning, and backward compatibility
• Working knowledge of message bus patterns and at least one broker technology (ZeroMQ, ActiveMQ, RabbitMQ)
• Experience with data serialization formats and communication protocols (protobuf, JSON, REST)
• Comfort in an Agile/Scrum environment: owned story-point commitments, contributed to planning, and hit sprint goals
• Strong debugging and troubleshooting skills in a multithreaded environment
• Clear written and verbal communication, write a design doc and present a trade-off to a non-technical stakeholder

What Makes You Stand Out

• Familiarity with Interface Control Documents (ICDs) for sensor or hardware systems
• Experience with object-oriented design patterns applied to integration or plugin architectures
• Prior work in defence, C2, or real-time systems
• Experience mentoring or leading a small technical workstream

Security

It is a requirement that General Dynamics Mission Systems-Canada be registered with the Canadian Controlled Goods program and that all of its workforce be security assessed. Successful applicants must meet all applicable security requirements, including but not limited to the ability to obtain and maintain a Canadian government security clearance. Applicants may be required to meet additional security requirements in order to gain access to technical data, classified areas or information that is subject to international regulations. You must be eligible to work in Canada.

What We Offer 
The hiring range for this position is $85,000 to $110,000 CAD annual.

Our goal is to provide a fair and competitive offer based on an assessment of internal equity and your qualifications, including:

• Relevant experience
• Technical and non-technical skills
• Education and certifications

Our Benefits:
At General Dynamics Mission Systems–Canada, we prioritize work-life balance. As a fulltime regular/term employee, you can enjoy a supportive, friendly and respectful environment with a competitive total rewards package.

• Comprehensive medical, dental and vision coverage for you and your eligible dependents, from day one of employment at no cost to you. 
  • Flexible benefit options available (including HCSA).
  • Emergency medical travel insurance.
  • 24/7 virtual health care services. 
• Employee & Family Assistance Program (EFAP) – counselling, life coaching, lifestyle change support, and financial planning.
• Onsite fitness facilities & employee resource groups.
• Defined Contribution Pension Plan (DCPP) with employer contributions after 3 months of service.
  • Access to financial advisors for investment advice and comprehensive financial planning. 
  • Voluntary Registered Retirement Savings Plan (RRSP) accessible from day one. 
• Flexible time away to rest and renew with vacation, holidays, vacation purchase plan and parental leaves (with top up options).
  • Sick leave and disability programs. 
• Grow your career your way with free access to a learning platform offering a wide range of courses and resources.
  • Educational Assistance Program to support formal learning. 
  • Self-directed mentoring opportunities. 
  • Reimbursement for professional and industry-related memberships and dues.
• Employee discounts on travel, home and auto insurance, as well as services and activities.
  • Free onsite parking.
  • Annual scholarship program for children of GD employees.
  • Employee social clubs and recreational activities.

Why join us?

• Purposeful Innovation: You’ll work on innovations that genuinely make a difference. You’ll apply advanced thinking, design expertise, and practical problem-solving to help equip military and allied forces with leading-edge systems. You’ll be surrounded by some of the brightest minds in the defence sector, contributing to next-generation technologies in an environment that celebrates creativity, new ideas, and modern solutions.
• Connection: We believe people do their best work when they feel they belong, and their ideas can flourish. Different perspectives, experiences, and ways of thinking help us innovate and grow. Strong relationships with our teammates help us unite, overcome challenges, and deliver the world-class quality we’re known for. Here, we are committed to inclusivity and ensures every individual feels valued, respected, and empowered.
• Challenging and Rewarding Career Pathways: Your career path matters to us. From mentorship and regular check-ins with your leader to educational support, professional certifications, and continuous training, you’ll have the resources you need to thrive. We encourage internal mobility so you can explore different business areas, broaden your skillset, and expand your network. You’ll be working on high-profile, impactful projects that challenge your skills, expand your expertise, and allow you to both learn from mentors and guide others along the way.

Accommodation 
If you require accommodation during any stage of the application process, please contact Human Resources via recruitment@gd-ms.ca.

Closing Date
We reserve the right to close this vacancy early if we receive sufficient applications for the role. Therefore, if you are interested, please submit your application as early as possible.