Senior Software Developer - Tax
Senior Software Engineer · Senior · Full Time
Opens Wealthsimple Technologies's application page
Role
What you'll do.
Senior Software Developer focused on tax products at Wealthsimple, Canada's leading fintech innovator. This full-stack role combines React frontend development with Python backend engineering to build and operate tax filing solutions serving 4+ million Canadians. You'll own complex end-to-end projects in a regulated financial domain while mentoring teammates, modernizing legacy systems, and leveraging AI-native development workflows.
Responsibilities
- Own End-to-End Engineering Projects: Lead complex, full-lifecycle software engineering projects from problem discovery and technical design through implementation, production launch, and ongoing iteration. Demonstrate accountability for project outcomes and drive continuous improvement of deployed systems.
- Full-Stack Development Across React and Python: Build and maintain full-stack tax application experiences using React for modern frontend interfaces and Python for robust backend services. Contribute to both greenfield development and modernization of legacy jQuery and Backbone components to improve codebase quality.
- Design Reliable Services and Tax Infrastructure: Architect and operate dependable backend services, API integrations, and workflows supporting critical tax filing, reporting, and compliance functions. Ensure systems meet regulatory requirements and deliver consistent performance for financial software serving millions of users.
- Technical Leadership and Mentorship: Raise engineering standards through design reviews, constructive code reviews, comprehensive documentation, pair programming sessions, and mentorship of junior engineers. Help shape technical direction and foster a culture of continuous learning and shared ownership.
- Cross-Functional Collaboration: Partner effectively with Product Management, Design, Operations, Compliance, and other engineering teams to clarify requirements, surface technical and business trade-offs, and deliver practical solutions in a regulated financial environment.
- Engineering Excellence and Observability: Make thoughtful architectural decisions balancing security, testing, monitoring, observability, and long-term maintainability. Establish best practices for API design, automated testing strategies, debugging workflows, and operational excellence.
- AI-Powered Development Workflows: Leverage AI-native development tools and large language models to accelerate design, implementation, debugging, and code quality. Maintain engineering rigor and personal accountability for all deliverables while using AI thoughtfully to improve productivity.
- Hiring and Team Building: Participate actively in the team's hiring process and technical interviews. Contribute to building a high-performing engineering organization that attracts and develops top talent.
Qualifications
What we look for.
Technical
Full-Stack Web Development
Proven expertise building and shipping production web applications across frontend and backend systems. Demonstrated proficiency with modern JavaScript frameworks, REST API design, and server-side application architecture.
React Frontend Framework
Strong professional experience with React or comparable modern frontend frameworks. Ability to build performant, maintainable, and user-centric interfaces. Experience with component architecture, state management, and frontend testing frameworks.
Python Backend Development
Professional experience developing backend systems with Python, or demonstrated ability to rapidly become productive in Python-based codebases. Understanding of Python best practices, testing, and deployment patterns.
API Design and Integration
Solid understanding of REST API design principles, authentication mechanisms, error handling, and integration patterns. Experience building integrations with third-party financial services or APIs.
Automated Testing and Quality Assurance
Strong commitment to test-driven development. Hands-on experience with unit testing, integration testing, and testing frameworks. Understanding of testing strategies for critical financial systems.
Monitoring, Observability, and Debugging
Proficiency with application monitoring tools, logging frameworks, and debugging techniques. Experience setting up observability infrastructure and using metrics and alerts to maintain production system reliability.
Version Control and Collaboration Tools
Strong proficiency with Git version control and collaborative development workflows. Experience with code review processes and pull request management in team environments.
Education
Computer Science or Related Field
Bachelor's degree in Computer Science, Software Engineering, Mathematics, or related technical discipline. Equivalent professional experience and self-directed learning may substitute for formal degree in some cases.
Continuous Learning in Software Engineering
Demonstrated commitment to staying current with software engineering trends, architectural patterns, and best practices through conference attendance, technical writing, open-source contributions, or advanced certifications.
Experience
Senior-Level Software Engineering Track Record
Minimum 7+ years of professional software engineering experience with a documented history of shipping, launching, and operating production systems at scale. Demonstrated progression toward senior engineering responsibilities.
Technical Project Leadership
Proven ability to lead complex technical projects independently, break down ambiguous business requirements into clear technical specifications and deliverable milestones, and drive projects to completion.
Mentorship and Team Development
Established track record of mentoring junior and mid-level engineers. Demonstrated ability to improve the technical effectiveness and professional growth of teammates through pairing, code reviews, and knowledge sharing.
Regulated or High-Trust Domain Experience
Experience working in regulated industries (fintech, financial services, healthcare, payments) or high-trust environments where security, compliance, and reliability are paramount.
Cross-Functional Product Engineering
Experience working closely with non-technical stakeholders including Product Managers, Designers, Operations teams, and Compliance. Ability to communicate technical concepts to diverse audiences and negotiate trade-offs.
Skills
Required
React
Production-level proficiency with React including component design patterns, state management (Redux, Context API, or alternatives), hooks, and performance optimization techniques.
Python
Strong backend development skills in Python with experience in frameworks like Django, FastAPI, or Flask. Understanding of Python packaging, virtual environments, and dependency management.
System Design and Architecture
Ability to design scalable, maintainable systems architecture. Experience making trade-off decisions between performance, simplicity, security, and cost.
Software Engineering Fundamentals
Mastery of core engineering principles including API design, automated testing, debugging strategies, monitoring implementation, and operational best practices for production systems.
Code Quality and Testing
Expertise in writing clean, maintainable code with comprehensive test coverage. Proficiency with testing frameworks and test-driven development methodologies.
Problem Solving and Ambiguity Navigation
Ability to tackle undefined problems with sound judgment, break them into manageable components, and drive toward practical solutions with incomplete information.
Communication and Collaboration
Exceptional written and verbal communication skills for technical and non-technical audiences. Ability to gather requirements, explain technical decisions, and document complex systems clearly.
AI-Native Development Workflows
Comfort using modern AI coding assistants and large language models (Claude, ChatGPT, GitHub Copilot) to accelerate development while maintaining accountability and engineering rigor.
Preferred
Fintech or Regulated Financial Services Experience
Nice to havePrior experience building software in fintech, tax technology, accounting, payments, or other regulated financial-services domains. Familiarity with compliance requirements and financial data handling.
Canadian Tax System Knowledge
Nice to haveFamiliarity with Canada Revenue Agency (CRA) processes, Canadian tax filing requirements, tax reporting mechanics, or experience with tax preparation software products.
Accounting Software Integration
Nice to haveExperience integrating with or extending accounting platforms such as QuickBooks, Xero, or similar systems. Understanding of accounting workflows and data models.
Legacy Codebase Modernization
Nice to haveHands-on experience planning and executing migrations of legacy frontend codebases (jQuery, Backbone, older frameworks) to modern architectures. Knowledge of incremental refactoring strategies.
Fast-Moving Product Engineering Culture
Nice to haveBackground working in fast-paced product engineering teams with broad individual ownership, rapid iteration cycles, and strong product-engineering collaboration.
Infrastructure and DevOps Fundamentals
Nice to haveUnderstanding of deployment pipelines, containerization (Docker), cloud platforms (AWS, GCP, Azure), and infrastructure-as-code principles to support full-stack ownership.
Database Design and Optimization
Nice to haveExperience designing relational database schemas, writing optimized SQL queries, and debugging database performance issues in production systems.
Tech stack
Languages
Frameworks
Databases
Tools
Other
Compensation
Pay and benefits.
Base·CAD 151,200 – 189,000
Equity·Stock options
Benefits
Comprehensive Health and Wellness Coverage
Top-tier health insurance including medical, dental, and vision coverage with employer contributions. Life insurance provided to ensure financial security for you and your family.
Long-Term Savings and Retirement Planning
Access to Wealthsimple for Business group savings program with employer matching contributions, enabling tax-advantaged retirement planning and wealth building.
Generous Time Off and Wellness
20 vacation days annually plus 4 dedicated wellness days. Unlimited sick and mental health days to support your wellbeing and work-life balance without guilt or restrictions.
Global Work Flexibility
Ability to work outside Canada for up to 90 days per year, providing flexibility for travel, remote work, or international experiences while maintaining employment.
Employee Resource Groups and Community
Inclusive community through employee resource groups including Rainbow (2SLGBTQ+), Women of WS, and Black at WS. Opportunities to connect with colleagues and advocate for underrepresented groups.
Hybrid Work Environment
Collaborative hybrid team model across North America with flexibility to balance office collaboration and remote work. Access to a network of talented, driven teammates across 1,500+ employees.
Professional Development and Innovation
Culture emphasizing continuous learning, experimentation with new technologies and AI tools, and professional growth. Participation in hiring and mentoring contributes to your career development.
Accessibility and Inclusivity
Commitment to accommodating candidates and employees with accessibility needs throughout hiring and employment. Diverse, inclusive workplace culture built to serve diverse customer base.
Full posting
Original listing.
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 and learn more about how we work.
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 engineering environment with broad individual ownership.
Why Wealthsimple?
🌸 Top-tier health benefits and life insurance
📈 Long-term group savings with employer match, through Wealthsimple for Business
🌴 20 vacation days, 4 wellness days, and unlimited sick and mental health days per year
✈️ 90 days away: work outside Canada for up to 90 days per year
👥 Employee resource groups, including Rainbow (2SLGBTQ), Women of WS, and Black at WS
🌎 We are a hybrid team with over 1,500 employees across North America. The people are one of the best parts of working here: you'll collaborate with incredibly talented, curious, and driven teammates who are deeply committed to doing great work.
ICYMI
Technology & Innovation at Wealthsimple: We move quickly and build thoughtfully. That means we're always looking for better ways to work — whether that's new tools, AI, or rethinking how we approach a problem. We don't expect you to have all the answers, but we do expect curiosity and a willingness to evolve alongside the products we're building.
Inclusion Statement: We're building products for a diverse world, and we need a diverse team to do it well. We strongly encourage applications from everyone, regardless of race, religion, colour, national origin, gender, sexual orientation, age, marital status, or disability status.
Accessibility Statement: We're committed to an accessible hiring experience. If you need any accommodations throughout the interview process, please let us know — we'll work with you to make sure you have what you need. We also welcome any feedback on how we can better accommodate candidates with accessibility needs.
AI in Hiring: We may use artificial intelligence (AI) tools to support parts of our hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our team but don't replace human judgment – all final hiring decisions are made by people. If you have questions about how your data is used, reach out to us.
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