Backend Developer (.NET)

Appnovation Technologies · Vancouver

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As a Senior Software Engineer - Backend, you will build the .NET services that carry the core business logic of a modern operational SaaS platform for K-12 education. The platform automates administrative processes for school divisions, so the backend work is workflow-heavy and integration-heavy: you will develop REST APIs consumed by a Next.js frontend, implement durable multi-step business processes as Temporal workflows, build worker services for asynchronous and scheduled processing, and write the integration services that publish and consume events across system boundaries.

You will work as part of a dedicated, cross-functional scrum team that operates as an embedded extension of the client's engineering organization. The team includes business analysis and QA capability and owns assigned product services end-to-end - from refinement through development, testing, documentation, and release readiness. You will work directly in the client's repositories, follow their established architecture and engineering standards, and deliver in small, reviewable increments.

The data layer spans a PostgreSQL transactional model and a ClickHouse analytics store, with authorization enforced through Keycloak and OpenFGA - a real requirement in a multi-tenant product where an administrator in one school division must never see another's data. The platform is moving from pilot deployments toward general availability, so this is a role for a senior engineer who cares about correctness in distributed systems - idempotency, retries, and what happens when the third call fails - and who is ready to own significant slices of the platform with minimal supervision.

Key Responsibilities:

• Developing and maintaining .NET Core REST APIs, including versioning, validation, error semantics, and Swagger/OpenAPI documentation
• Building worker services for background, scheduled, and queue-driven asynchronous processing
• Writing integration services that publish and consume events over pub/sub, against clearly defined message contracts
• Modelling and querying relational data in PostgreSQL using Entity Framework Core, including migrations and query performance tuning
• Building and maintaining API calls into ClickHouse
• Enforcing authorization in application code against OpenFGA policies, and integrating with Keycloak for OAuth 2.0 / OpenID Connect authentication and SSO
• Producing technical analysis and implementation plans for significant changes, and delivering work in small, reviewable merge requests
• Writing unit, integration, and API tests, and contributing to the Playwright end-to-end suite where backend behaviour is under test
• Participating in code review, responding to CodeRabbit findings, and keeping GitLab CI/CD pipelines green
• Instrumenting services with logging, metrics, and tracing to support production diagnosis
• Participating in refinement, planning, review, and retrospective as a member of a self-directed scrum team, and raising missing business decisions early
• Taking ownership of feature areas end to end, from technical design through release and support
• Maintaining technical implementation and API documentation as part of the definition of done, not after it
• Resolving defects and supporting post-release stabilization of recently delivered functionality
• Mentoring less experienced engineers through code review and pairing

What we are looking for

Must-Have:

• At least 5-7 years of professional backend development experience with C# and .NET in production environments
• Strong command of .NET Core, ASP.NET Core Web API, and Entity Framework Core
• Demonstrated experience building RESTful APIs consumed by real frontend or third-party clients
• Solid relational data modelling and SQL skills in PostgreSQL or an equivalent RDBMS, including query performance tuning
• Practical experience with asynchronous processing - background workers, message queues, or scheduled jobs
• Working understanding of async/await in .NET and the failure modes that come with it
• Understanding of event-driven and pub/sub patterns, including at-least-once delivery and idempotent consumers
• Experience integrating with an identity provider using OAuth 2.0 and OpenID Connect
• Comfortable working inside an existing codebase and an established set of engineering standards, rather than setting your own
• Disciplined approach to automated testing across unit, integration, and API layers
• Understanding of what makes automated tests durable - avoiding hard-coded waits, brittle selectors, shared test state, and environment-specific assumptions
• Comfortable working in a Git-based workflow with CI/CD and peer code review
• Must be located in Vancouver, British Columbia, Canada

Technologies

• Languages/Frameworks: C#, .NET Core, ASP.NET Core, Entity Framework Core
• APIs: REST, OpenAPI/Swagger, API versioning
• Workflow and Async: Temporal workflows, worker services, asynchronous processing, event-driven pub/sub, integration services
• Databases: PostgreSQL, ClickHouse, EF Core migrations, query optimization
• Identity and Authorization: Keycloak, OpenFGA, OAuth 2.0, OpenID Connect, role- and policy-based authorization
• Testing: xUnit/NUnit, Moq, Testcontainers, unit, integration and API testing, Playwright end-to-end testing
• Build/Deploy/Tooling: GitLab, GitLab CI/CD, CodeRabbit automated code review, Docker, Jira, Confluence

Nice-to-Have:

• Exposure to ClickHouse or another columnar/OLAP store for reporting workloads
• Familiarity with fine-grained authorization models (OpenFGA, Zanzibar-style ReBAC)
• Hands-on Temporal experience, including workflow versioning and testing strategies
• Working knowledge of TypeScript and React, enough to trace an issue across the stack
• Experience with distributed tracing and structured observability (OpenTelemetry)
• Familiarity with Domain-Driven Design and CQRS patterns
• SaaS product delivery experience, particularly through a pilot-to-GA transition
• Experience with Canadian public-sector or education data privacy requirements (PIPEDA, provincial FIPPA), including data residency considerations
• Experience in a consulting or client-facing delivery environment

Who you are

• You are a careful engineer who thinks about failure modes before writing the happy path, and who leaves code easier to change than you found it.
• You ask questions early, communicate clearly when something is off track, and take testing seriously rather than treating it as a step after the work.
• You treat a feature as incomplete until it is tested, documented, and supportable - finishing the code is the middle of the job, not the end.

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