Build and support complex features across C#/.NET back-end services and React front ends. Responsibilities include technical design, API and data modeling, secure and tested coding, production troubleshooting, code reviews, mentoring, documentation, and improving engineering practices. Collaborate with Product, QA, DevOps, Technical Leads, and architecture teams while balancing delivery, maintainability, performance, accessibility, observability, and security.
This is a remote position.
Senior Software Developer (C#/.NET and React)
Remote, Canada (occasional in-person team days in the Greater Toronto Area)
Full-time, permanent
About the company
Our client is an established, mission-driven Canadian technology organization. They run a high-traffic online payments platform used by thousands of organizations and a large base of individual users across the country. The engineering team is small enough that senior people have real influence, and the culture is collaborative, flexible and focused on doing work that matters.
The role
This is a senior hands-on engineering position. You will take large, sometimes loosely defined features and carry them all the way through: shaping the requirements, designing the solution, building it, testing it, shipping it and supporting it in production. The stack is a C#/.NET back end with a React front end.
You will be expected to make sound calls on your own, balance short-term delivery against long-term code health, and raise the level of the developers around you through reviews, mentoring and good technical conversation. You will work day to day with a Technical Lead, Product, QA and DevOps, and you should care about the "why" behind what the team builds, not only the "what" and "how".
What you will do;
Building and shipping
- Take ownership of complex features from early design through to production support
- Turn half-formed problems into clear, well-scoped technical work
- Write clean, secure, maintainable and well-tested code on both the front end and back end
- Flag risks, dependencies and blockers early in planning rather than late in delivery
- Dig into production issues on your own and fix root causes, not symptoms
Technical design
- Lead design at the feature level, covering APIs, data models and integrations
- Weigh trade-offs and recommend practical solutions
- Bring in the Technical Lead and architecture group when a decision has wider system impact
- Champion good practice around security, testing, observability, performance and documentation
- Simplify where possible, automate repetitive work and make life easier for other developers
- Build front-end experiences that are accessible, semantic and standards-compliant, with usability and SEO considered from the start
Raising the team
- Give thorough code reviews that look at correctness, design, security and maintainability
- Mentor other developers and help them grow more independent
- Share what you know through documentation, pairing, demos and workshops
- Influence how the wider team handles recurring technical problems
- Help improve how the team works, not just what it delivers
Requirements
- Around 6 or more years building and supporting complex production systems (what you have delivered matters more than the exact number)
- Strong C# and .NET skills, including RESTful APIs and back-end services
- Solid working knowledge of React and TypeScript/JavaScript
- Experience with relational databases such as SQL Server
- A history of troubleshooting production problems independently and leading design decisions
- Good technical judgment and comfort working through ambiguity
Nice to have
- Azure or another major cloud platform
- Automated testing and modern CI/CD
- Background in payments, fintech or another security-sensitive field
- Experience mentoring developers or building a strong code review culture
This is a current, open position. Our client is committed to an inclusive workplace and welcomes applicants from all backgrounds. All hiring decisions are made by people.
Similar Jobs
Consumer Web • Healthtech • Professional Services • Social Impact • Software
Lead compensation analysis and programs, including market pricing, pay ranges, compensation cycles, offers, promotions, equity, budget modeling, and process improvements. Build scalable compensation tools and frameworks, use AI and automation, improve data quality across Workday, Pave, and Carta, and advise HR, Talent Acquisition, Finance, and managers on compensation decisions.
Top Skills:
AIAutomationCartaGoogle SheetsExcelPaveWorkday
Consumer Web • Healthtech • Professional Services • Social Impact • Software
Leads Headway’s consumer communications and social function, including earned media, organic social, content marketing, data storytelling, and cultural relevance. Builds media relationships, manages an agency partner, develops content across blogs, YouTube, and Substack, grows engagement, and leads a small team. Partners with Communications, Brand, Product Marketing, research, and analytics to increase awareness and strengthen Headway’s presence across press, search, social, LLMs, and consumer conversations.
Top Skills:
LlmsSocial Media PlatformsSubstackYoutube
Artificial Intelligence • Cloud • HR Tech • Information Technology • Productivity • Software • Automation
Manage strategic relationships with GSI partners including KPMG and DXC. Develop joint go-to-market plans, coordinate sales, marketing, enablement, services, and partner programs, drive opportunity registration and forecasting, support deal execution, manage contracts and MDF, conduct business reviews, and serve as an escalation point. The role requires strong cybersecurity solution knowledge, executive partner relationships, channel sales experience, and a proven record of quota achievement.
Top Skills:
ArmisEdrServicenowVezaXdr
What you need to know about the Toronto Tech Scene
Although home to some of the biggest names in tech, including Google, Microsoft and Amazon, Toronto has established itself as one of the largest startup ecosystems in the world. And with over 2,000 startups — more than 30 percent of the country's total startups — Toronto continues to attract new businesses. Be it helping entrepreneurs manage their finances, simplifying business operations by automating payroll or assisting pharmaceutical companies in launching new drugs, the city's tech scene is just getting started.
