Senior Software Developer, Build Platform

📋 Job Overview

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.

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🏢 About Wealthsimple

At Wealthsimple, the Build Platform team is on a mission to make developing great software fast, intuitive, and enjoyable. We believe engineers should focus on building incredible features for our clients, not fighting their environment. Our job is to clear the path. We do this by treating our platform as a product. Our internal developers are our customers, and their success is our primary measure of impact.

🎯 The Role

As a Developer on our team, you won't just be building tools; you'll be shaping the entire developer journey at Wealthsimple. From their first day onboarding to their thousandth code submission, you'll be making the experience seamless. You will support a diverse engineering organization that uses Ruby, Python, Kotlin, and TypeScript to build the future of finance. Your work will directly empower hundreds of developers to ship high-quality, secure code to millions of users with confidence and speed.

The most interesting problem on our plate right now is AI. When agents write a large share of the code, the bottleneck stops being how fast you can produce a change and starts being how fast you can trust one. That makes verification the constraint on the whole company: reproducible environments, test signal you can believe, and feedback loops tight enough that an agent catches its own mistakes before a human ever sees them. Building that layer is the team's biggest bet, and this role sits at the centre of it.

✅ Key Responsibilities

• Build the substrate for agentic development. You'll roll out containerized development environments across hundreds of services so that engineers and coding agents alike get reproducible, isolated, fast environments to work in. This eliminates "works on my machine" and it is the foundation everything AI-native depends on.
• Build the verification layer for AI-native development. As agents generate more of our code, proving a change is safe becomes the constraint on how fast the whole company ships. You'll build the systems that give agents and developers a trustworthy answer in seconds rather than hours.
• Make test signal fast, deterministic, and actionable. Flakiness a human can shrug off is fatal to an agent iterating unattended. You'll attack flake detection, test selection, and failure output that is legible enough to act on without a person interpreting it.
• Modernize the core libraries and CLI that underpin our microservices architecture, automating developer machine setup and replacing legacy tools with safer, auditable alternatives. Well-shaped tooling is what makes humans and agents both effective.
• Solve the hard testing problems underneath all of it. You'll build robust backend mocking solutions, and enable isolated testing of asynchronous, event-driven workflows in ephemeral environments.
• Define and measure operational excellence at scale. You'll help build automated scorecards that give every team clear, actionable insight into the health of their services, covering everything from dependency management to monitoring and scalability.

📌 Required Qualifications

• 7+ years of experience in software development as part of a team, preferably a platform-oriented team.
• 7+ years experience with any of the following: Ruby, Python, Typescript, Kotlin.
• Experience designing, building, and maintaining internal libraries, frameworks, or tooling used by other engineering teams.
• Hands-on experience with AI-assisted development. You've used coding agents on real production work, you know where they break down, and you have opinions about what makes them effective.
• A builder's instinct for AI tooling. You've built with LLMs rather than only used them, and you've thought hard about how to evaluate whether what they produce is actually correct.
• Curiosity and a deep interest in a fast, reliable, streamlined developer experience. You're driven to understand your users, eliminate complexity, and build elegant solutions to their pain points, and you keep a close eye on where the industry is heading.
• A collaborative spirit and a passion for mentorship. You believe in making your colleagues successful and enjoy coaching other developers.
• A data-informed approach to decision-making. You are comfortable using metrics to identify opportunities and measure the impact of your work.

🎁 Benefits

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 while still receiving your salary

Base salary range: For this role, candidates located in Canada can expect a base salary range, described in the posting. Actual compensation is determined based on skills, experience, and role level. Exceptional candidates may be considered above the top of the range, and pay can increase quickly for those who make a big impact in the role.

Total compensation: In addition to base salary, permanent employees receive equity compensation. We use clear job levels and market-based salary bands to ensure compensation is fair and consistent across the company.