Senior Software Developer - Quality & Developer Tooling

Wealthsimple Technologies • Toronto, ON

4d • CA$151,200 - CA$189,000 • Hybrid

About The Position

As a Senior Software Developer on the CAP OpEx team, you own the application-level quality and tooling layer of our platform. Where our Site Reliability Engineer owns infrastructure, deployment, and system-level observability, you own the engineering complement: end-to-end test infrastructure, SDK instrumentation, test account tooling, and the internal developer automation that makes CAP engineers faster and more confident.
You build systems that other engineers depend on — not shipping product features to end users, but building the platforms and pipelines that let your colleagues do so safely at scale. This means thinking in systems, caring deeply about developer experience, and moving fluidly across the full stack: frontend SDKs, backend services, CI/CD. You're comfortable in a TypeScript/React codebase instrumenting an SDK one day and writing a backend script to automate a manual operational workflow the next.
You bring a deeply AI-native approach to your work beyond surface familiarity. You've made agentic coding tools like Claude Code a core part of your development workflow, and you can point to concrete ways they've multiplied your output. You have strong instincts for which problems AI can automate extremely well (rolling out analytics event wrappers across components, expanding e2e test coverage, scaffolding boilerplate tooling at scale) and you proactively design your systems and workflows to take advantage of that. You ask first "how could this be automated?" before reaching for the long way around.
Key areas you'll own and grow:
End-to-end testing platform - Architect and own CAP's e2e test suite across web and React Native mobile. This is framework architecture work: runner configuration, CI integration, test standards, and reliability at scale.
SDK observability & instrumentation - Instrument our Account-Opening SDK with standardized analytics events and structured logging, leveraging React hooks and context patterns to give Wealthsimple visibility into frontend onboarding flows.
Test account & staging tooling - Own and evolve CAP's staging and production test account tooling so every team at Wealthsimple can reliably create accurate test accounts for every environment. CAP owns account creation, we should own test account creation too.
Developer automation - Build internal tools and automation that cut manual operational work across the CAP domain: feature flag cleanup, automated triage, AI-powered developer workflows, and whatever the team's highest-leverage opportunities turn out to be.
Quality gates & coverage - Drive shift-left quality practices: mutation testing, code coverage improvements, and CI gates that catch issues before they reach production.

Requirements

• Demonstrated experience building developer tooling, test frameworks, or internal platforms. Not just using them; you've designed and owned the systems themselves
• Strong proficiency in TypeScript/JavaScript with hands-on experience in React and/or React Native contexts, particularly building shared libraries, SDKs, or instrumentation rather than product UIs
• Backend development experience (Ruby, Python, Go, or equivalent) and comfort working across APIs, databases, and service-layer code
• A quality engineering mindset. You think about testability, observability, and reliability from the start, not as an afterthought
• An AI-native approach to your craft. You use agentic coding tools as a core part of your workflow, not a novelty, and have a genuine track record of using them to move faster and smarter on the problems they're well-suited for

Nice To Haves

• experience designing and implementing end-to-end or integration test frameworks across web and mobile
• experience instrumenting frontend SDKs with analytics or observability tooling, or building analytics event pipelines

Responsibilities

• Architect and own CAP's e2e test suite across web and React Native mobile.
• Instrument our Account-Opening SDK with standardized analytics events and structured logging.
• Own and evolve CAP's staging and production test account tooling.
• Build internal tools and automation that cut manual operational work across the CAP domain.
• Drive shift-left quality practices: mutation testing, code coverage improvements, and CI gates.

Benefits

• 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

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed