Senior Application Developer jobs in Caledon, ON

Location: Onsite Department: Engineering Reports To: Engineering Manager

About the Role

We're looking for a Senior Software Engineer to join our engineering team and take ownership of the backend systems powering our platform. You'll work closely with our existing frontend team, product, and leadership to design, build, and scale services that are reliable, secure, and ready to grow with the business. This is a senior-level, high-ownership role for someone who can operate independently, make sound architectural calls, and mentor other developers along the way.

While this role leans backend-heavy, you'll be comfortable moving across the stack when needed — our frontend is covered, but we value engineers who understand the full picture.

What You'll Do:

• Design, build, and maintain backend services and APIs that power our core platform, with a focus on reliability, performance, and maintainability
• Own and evolve our data layer — schema design, query optimization, and data integrity across relational databases
• Architect systems for scale: think through concurrency, caching, queuing, and failure modes before they become problems
• Collaborate with frontend engineers to define clean API contracts and ensure smooth integration between services and UI
• Deploy, monitor, and maintain services in a cloud environment (AWS or equivalent), including CI/CD pipelines and infrastructure-as-code where applicable
• Write clear technical documentation — specs, architecture decisions, API docs — that the rest of the team (and future hires) can actually use
• Participate in code review, set technical standards, and mentor junior/intermediate developers
• Work cross-functionally with product and leadership to translate business requirements into technical roadmaps
• Troubleshoot and resolve production issues, with an eye toward root cause rather than quick patches
• Contribute to technical decision-making around tooling, architecture, and process as the team and product scale

What We're Looking For:

• 7+ years of professional software engineering experience, with a strong track record in backend development
• Deep expertise in at least one modern backend language (Go, Node.js/TypeScript, Python, or similar) — Go experience is a strong plus
• Solid experience designing and consuming RESTful APIs understanding of API security and versioning best practices
• Well versed in using AI platforms to code (i.e. Claude Code, Codex, Cursor)
• Strong database fundamentals — schema design, indexing, query performance, both SQL and NoSQL exposure
• Hands-on experience with cloud infrastructure (AWS preferred) — EC2, Lambda, RDS, S3, or equivalent services
• Comfortable working with containerization and CI/CD pipelines (Docker, GitHub Actions, CircleCI or similar)
• Experience designing systems for scale and reliability — caching strategies, async processing, rate limiting, observability/monitoring
• Working knowledge of frontend frameworks (React/Next.js or React Native) — you don't need to live here, but you should be able to read the room
• Proven ability to work independently, own a problem end-to-end, and make pragmatic architectural decisions with limited oversight
• Strong written communication skills — comfortable producing specs, documentation, and roadmap material
• Experience mentoring other engineers or acting as a technical lead on a small team

Nice to Have:

• Experience with IoT, device communication protocols, or hardware-integrated systems
• Familiarity with EV charging infrastructure or protocols such as OCPP/OCPI
• Experience working in an early-stage or startup environment where you're wearing multiple hats
• Exposure to building internal tooling, admin dashboards, or CMS-style platforms

Pay: $105,000.00-$125,000.00 per year

Benefits:

• Casual dress
• Dental care
• Employee assistance program
• Flexible schedule
• On-site parking
• Paid time off
• Vision care

Work Location: In person