Senior C# Back-end Developer

We're looking for an expert-level C# back-end developer to join a delivery team in Montreal. This is a pure back-end role focused on server-side and standalone desktop application development candidates with primary experience in web, frontend, or full stack development are not the right fit for this position. What You'll Do Develop, refactor, and optimize back-end server-side and standalone desktop application components Identify and resolve underperforming code to improve application efficiency and performance Write robust, well-structured code with strong attention to multithreading, data structures, and algorithms Perform code reviews and contribute to cross-team tasks, release management, and regression checking Participate in testing efforts including applying TDD and BDD methodologies to new and existing codebases What You Bring 8+ years of professional C# development experience in a back-end or standalone desktop application context Expert-level proficiency in C# and the Visual Studio environment Strong skills in multithreaded programming, data structures, algorithms, SQL, and application optimization Proven experience identifying, detecting, and refactoring underperforming code Hands-on exposure to technologies including SQL Server, gRPC, Hibernate, WinForms, WCF, REST APIs, and Swagger Deep understanding of programming concepts and genuine curiosity about how APIs and architectural choices work internally Eligibility for a mandatory background check Nice to have Prior experience in finance, trading, or domain knowledge across asset classes, rates, FX, fixed income, or structured products Familiarity with TDD and BDD concepts and practical application in existing codebases French language proficiency Work setup Montreal, QC with up to 2 days remote per week after 3 months, subject to manager discretion 6+ month contract English required; French is a plus Quebec statutory holidays apply

Develop, refactor, and optimize back-end server-side and standalone desktop application components. Participate in testing efforts including applying TDD and BDD methodologies to new and existing codebases.

Candidates should have 8+ years of professional C# development experience in a back-end or standalone desktop application context. Strong skills in multithreaded programming, data structures, algorithms, and SQL are required.

Identified from the job description. Confirm important requirements above.

• C#
• Visual Studio
• Multithreading
• Data Structures
• Algorithms
• SQL
• Application Optimization
• gRPC
• Hibernate
• WinForms
• WCF
• REST APIs
• Swagger
• TDD
• BDD

• Technology
• Engineering
• Software
• Consulting

Minimum experience

10+ years

Apply by

Dec 12, 2026

Posting language

English

Working hours

40 hours per week

Office presence

3 days per week

Seniority

Mid-Senior level