Senior Backend Developer

Senior Software Engineer – NX, NestJS, TypeScript/Node.js, Kafka & MongoDB Toronto, ON - Hybrid (4 Days WFO) Experience: 8+ years in software engineering| with strong hands-on experience in TypeScript/Node.js| NestJS| and NX monorepo delivery Role Summary We are hiring a senior engineer to help deliver the AVA Modernization program| moving a legacy platform to a cloud-native architecture using NX monorepo| NestJS services| event-driven integration| and MongoDB/Snowflake data patterns. This is a hands-on role with architecture influence across BFF| microservices| ingestors| and workers. Key Responsibilities • Build and scale services within a single NX monorepo using shared libraries and dependency-aware CI/CD. • Develop and evolve a NestJS BFF Gateway for multiple frontends| including JWT validation and OBO token exchange with Azure Entra ID. • Implement internal NestJS microservices with clear domain ownership and independent deployment. • Build ingestion services that consume external events| transform payloads| persist operational data| and publish internal domain events. • Develop async workers that process internal events for side effects (notifications| indexing| jobs) without tight service coupling. • Contribute to data-layer design: • MongoDB for operational/current-state reads • Snowflake for analytical/reporting workloads • Create and maintain shared libs/ contracts (DTOs| event payloads| auth utilities| API clients| validation rules). • Ensure strong testing| observability| performance| and production reliability standards. Required Qualifications • 5-10 years of backend engineering experience. • Strong hands-on expertise with NestJS (modules| DI| guards| interceptors| pipes| validation| Swagger/OpenAPI). • Practical experience with NX monorepos (shared libs| dependency graph| affected builds/tests). • Advanced TypeScript/Node.js skills and API/event contract design. • Experience with event-driven systems (Kafka or equivalent)| including retries| idempotency| and schema/version evolution. • Experience building BFF/API orchestration layers across multiple upstream services. • Solid MongoDB experience for low-latency operational workloads. • Strong communication and collaboration skills in cross-functional delivery teams. Preferred Qualifications • Ability to navigate and analyze C# and/or Java codebases at a working level a significant portion of source-of-truth analysis will involve reading and interpreting existing legacy code in these languages to understand current business logic and inform how it should be reshaped to fit the new architecture. • Experience with Azure Entra ID and OAuth/OBO flows. • Exposure to GraphQL supergraph integrations from BFF layers. • Snowflake or similar analytical platform experience. • Experience migrating legacy services to containerized/cloud-native architectures. • Kubernetes/OpenShift delivery exposure.