Principal Software Engineer (Backend)

Location: Toronto, Ontario

Our client is a fast-growing Canadian fintech building modern, customer-facing financial products at the intersection of technology and personal finance. AI is treated as a practical, everyday enabler across their engineering teams, and they are looking for builders excited to fold those tools into how they work and what they ship. This is a collaborative, mission-driven environment where engineers are given real ownership and room to grow.
We are searching for a hands-on Principal Software Engineer to set the technical direction for backend development across the platform. You will lead the architecture and build of next-generation services and APIs, with a primary emphasis on distributed systems and server-side engineering. Beyond the code, you will mentor a skilled team, push innovation forward, and ensure every service is fast, resilient, and secure. The right person is a strategic thinker who genuinely enjoys solving hard problems around scale, data, and reliability.
What you will do:
- Set the vision: Own the long-term technical roadmap for backend systems, tied to business priorities and industry direction.
- Architect and build: Drive the design and development of complex, high-performance services and APIs, making the key calls on languages, frameworks, data stores, and patterns for scalability and maintainability.
- Lead and mentor: Serve as a technical anchor for the team, coaching intermediate and senior engineers, modeling technical excellence, and contributing hands-on code.
- Optimize for scale and real-time data: Resolve performance and throughput bottlenecks, and design resilient approaches for high-frequency, real-time data processing so trading and live experiences stay fast and reliable.
- Raise the bar on quality: Define and uphold backend standards across code quality, service design, observability, testing, CI/CD, and security.
- Explore what is next: Lead research, prototyping, and adoption of emerging backend technologies to keep the platform modern and competitive.
- Champion AI in engineering: Drive thoughtful adoption of AI tools to lift developer productivity and enhance product capabilities, and help spread good AI practices across squads.
- Collaborate across the org: Partner with product, architecture, front-end, and fellow engineering leaders to shape the roadmap and ensure smooth integration.
- Solve the hardest problems: Take on the toughest backend challenges including distributed systems, data consistency, fault tolerance, and performance at scale.
Compensation: Competitive base salary plus an annual incentive/bonus program, comprehensive health and benefits, paid vacation/personal/sick days, and a hybrid working model (minimum 3 days in office).

Must Have Skills:
8+ years of professional software engineering experience with a heavy backend focus and a track record of shipping large-scale, production-grade systems.
Expert, hands-on command of one or more server-side languages (e.g., Java, Go, C#, Python, or Node.js) and a deep grasp of building scalable, distributed services.
Strong, practical experience designing RESTful APIs plus solid command of relational and NoSQL data stores and data modeling.
Demonstrated success designing, building, and scaling complex, high-traffic backend systems, with command of microservices, system design, and storage patterns.
Proven backend performance work (profiling, query optimization, caching, throughput tuning) and understanding of real-time streaming and messaging technologies such as Kafka, WebSockets, or similar.
Experience leading or mentoring technically, guiding discussions, influencing peers, and making pragmatic long-term decisions.
Excellent communication skills and a strong sense of ownership and accountability.

Nice to Have Skills:
Familiarity with cloud platforms (AWS, GCP, or Azure), containerization, and orchestration (Docker, Kubernetes).
Experience with event-driven or gRPC API design.
Exposure to fintech, trading, or other low-latency, high-reliability domains.
Hands-on experience adopting AI tooling to improve developer productivity.