Senior Software Developer - Tax

BUILD SOMETHING PEOPLE LOVE Wealthsimple is Canada’s leading financial innovator. The company offers a full suite of simple, sophisticated financial products across managed investing, do-it-yourself trading, cryptocurrency, tax filing, spending and saving. Wealthsimple currently serves more than 4 million Canadians and holds over $155 billion in assets under administration. The company was founded in 2014 by a team of financial experts and technology entrepreneurs, and is headquartered in Toronto, Canada. We're proud of what we've built — and we're just getting started. Read our Culture Manual https://www.wealthsimple.com/en-ca/culture and learn more about how we work https://www.wealthsimple.com/en-ca/careers. ABOUT THE ROLE As a Senior Software Developer on the Tax team, you will work across the stack to build, improve, and operate products that help Canadians complete their tax obligations with confidence. You will take meaningful projects from discovery and technical design through implementation, launch, and iteration. You’ll help shape technical direction, raise engineering standards, and mentor teammates while contributing directly to production code. This role is a strong fit for someone who enjoys complex, regulated domains; can work comfortably across frontend and backend systems; and brings sound judgment to ambiguous problems. WHAT YOU’LL DO - Own complex, end-to-end engineering projects, from problem definition and technical design through delivery and ongoing improvement. - Build and maintain full-stack experiences using React on the frontend and Python on the backend. - Contribute to existing frontend code, including legacy jQuery and Backbone components, while helping the team modernize and simplify the codebase over time. - Design and operate reliable services and integrations that support tax filing, reporting, and other critical client workflows. - Partner with Product, Design, Operations, Compliance, and other engineering teams to clarify requirements, surface trade-offs, and deliver practical solutions. - Make thoughtful decisions about architecture, testing, observability, security, and maintainability. - Use AI-native development workflows to improve the speed and quality of design, implementation, debugging, and programming. - Raise the technical bar through design reviews, code reviews, documentation, pairing, and mentorship. - Participate in the team’s hiring and interview process. - Help create a culture of clear communication, learning, and shared ownership. WHAT YOU BRING - Significant professional software engineering experience, with a track record of shipping and operating production systems. - Strong full-stack development experience, including React or a comparable modern frontend framework. - Professional experience with Python, or demonstrated ability to become productive quickly in Python-based systems. - Experience leading complex technical projects and breaking ambiguous problems into clear, deliverable steps. - A history of mentoring engineers and improving the effectiveness of the people around you. - Strong engineering fundamentals, including API design, automated testing, debugging, monitoring, and operational excellence. - The ability to collaborate effectively with technical and non-technical partners in a regulated or high-trust environment. - Clear written and verbal communication, sound judgment, and a low-ego approach to feedback and teamwork. - An AI-first development workflow that uses tools such as Claude thoughtfully while maintaining engineering rigor and accountability for the final result. HELPFUL EXPERIENCE - Experience in fintech, tax, accounting, payments, or another regulated financial-services domain. - Familiarity with Canada Revenue Agency processes, tax reporting, or tax-filing products. - Experience with accounting platforms such as QuickBooks. - Experience modernizing or migrating legacy frontend codebases. - Experience working in a fast-moving product engineer…