Senior Net Core Developer Jobs in Toronto, ON (NOW HIRING)

Why you'll love working here:

• high-performance, people-focused culture

• our commitment that equity, diversity, and inclusion are fundamental to our work environment and business success, which helps employees feel valued and empowered to be their authentic selves

• learning and development initiatives, including workshops, Speaker Series events and access to LinkedIn Learning, that support employees' career growth

• membership in HOOPP's world class defined benefit pensionplan, which can serve as an important part of your retirement security

• competitive, 100% company-paid extended health and dental benefits for permanent employees, including coverage supporting our team's diversity and mental health (e.g., gender affirmation, fertility and drug treatment, psychological support benefits of $2,500 per year, parental leave top-up, and a health spending account).

• optional post-retirement health and dental benefits subsidized at 50%

• yoga classes, meditation workshops, nutritional consultations, and wellness seminars

• the opportunity to make a difference and help take care of those who care for us, byproviding a financially secure retirement for Ontario healthcare workers

Job Summary

The Pension Application Development Team (PAD) is seeking a Senior API Integration Engineer to support the growth of our Digital Insight Services Platform (DISP).

Reporting to the Sr. Director, Pension Application Developer, the Senior API and Integration Engineer will lead API integration design and delivery You will build services and shape integration patterns ensuring legacy and core systems remain stable and secure and enabling web and mobile experience teams to move independently through a stable DISP Orchestration API / Backend-for-Frontend layer.

You will act as a technical lead on programs and projects to help establish scalable engineering practices that improve speed, resilience, security, observability, and long-term maintainability. The Senior API and Integration Engineer will partner with Architecture, Product, Front-End Engineering, QA, Security, Infrastructure, and vendor delivery teams in supporting the growth of our DISP program. We value thoughtful innovation, secure engineering, shared ownership, and continuous learning.

What you will do:

Development and Maintenance

• Own the design and implementation of DISP Orchestration APIs using the Backend-for-Frontend pattern to support new web and mobile experiences.

• Build and evolve RESTful APIs and integration services using.NET Core, Azure Functions, and cloud-native Azure services.

• Lead complex integrations between modern digital platforms and legacy systems (e.g., Telus Health pension administration).

• Design integration layers that decouple digital channels from core systems, allowing front-end teams to move independently without over-coupling to backend constraints.

• Design secure, token-based API interactions using JWT, OAuth/OIDC patterns, managed identity, Key Vault, private endpoints, and least-privilege access controls.

• Implement resilience patterns (e.g., retries, idempotency, asynchronous workflows, messaging, caching).

• Guide API versioning, contract stability, schema evolution, backward compatibility, and deprecation practices across squads and releases.

• Create API designs that align to UX needs, frontend state requirements, error handling, performance expectations, and member experience outcomes rather than simply exposing backend system structures.

• Design and maintain integration flows where writes may trigger downstream workflows, audits, status tracking, reconciliation, and eventual consistency across systems.

• Implement caching and read-model strategies using Redis, materialized views or projections, or equivalent patterns to improve performance and reduce load on legacy platforms.

• Ensure high-quality, secure code through reviews, automated testing, and CI/CD practices.

• Lead the resolution of complex production issues across API, identity, and system boundaries

Agile and Collaboration

• Serve as a senior technical reference point for API integration decisions across our development squads.

• Co-lead program and project delivery activities for significant new Digital Integration Services Platform-DISP integration workstreams, including technical planning, sequencing, dependency management, and launch readiness.

• Influence integration standards through practical patterns, reusable templates, and clear guidance

• Communicate complex technical risks and decisions clearly to technical and non-technical partners.

• Contribute to backlog refinement, estimation, sprint planning, demos, retrospectives, and release planning with a focus on predictable delivery and long-term platform health.

• Challenge designs constructively where they increase coupling, create brittle dependencies, reduce auditability, or introduce avoidable production risk.

• Build bridges across teams and vendors to align integration approaches, resolve dependencies, support knowledge transfer, and strengthen internal engineering capability.

• Foster an inclusive, respectful team environment that supports learning and shared ownership

Development and Delivery

• Own production-critical API paths from technical design through implementation, testing, release, monitoring, support, and continuous improvement.

• Define implementation approaches for key integration features, including API design, data flow, security, and testing.

• Establish quality gates for APIs, including unit tests, integration tests, contract tests, API tests, performance tests, security tests, regression coverage, and release-readiness checks.

• Design for zero-downtime or low-disruption releases by applying backward-compatible changes, versioning discipline, feature toggles where appropriate, and clear operational runbooks.

• Proactively identify and address risks to delivery, system reliability, and user experience.

• Support incident response, production defect triage, root-cause analysis, service restoration, and permanent corrective actions for DISP integration services.

• Define practical monitoring, alerting, dashboard, and support procedures that allow teams to detect issues before they become member-impacting incidents.

• Guide teams through trade-offs between synchronous APIs, asynchronous workflows, caching, event processing, eventual consistency, backend capability, and user experience needs.

• Ensure integration designs protect core record keeping calc engine (Ariel, Insight), and other core systems from misuse, over-coupling, excessive load, duplicate writes, untracked workflow state, and inconsistent data handling.

What you will bring:

• 10+ years of software engineering experience with 6+ years of focused experience in APIs, integration engineering, backend platform engineering, or service-oriented application development.

• 3+ years designing and delivering integrations in cloud-native Azure environments with strong knowledge of Azure integration services, including Azure Functions, Azure Service Bus, Azure SQL, Redis or equivalent caching, Key Vault, managed identity, API gateway patterns, and App Insights.

• Strong experience building secure, reliable RESTful APIs in .NET, ASP.NET Core, Azure Functions, or comparable enterprise API frameworks.

• Experience with API gateways, Azure API Management, Tyk, F5/WAF patterns, throttling, rate limiting, and centralized API policy enforcement.

• Experience leading technical delivery and outcomes across complex, multi-year initiatives under ambiguity, time pressure, and cross-team dependency constraints

• Strong communication skills, with the ability to collaborate across technical and business teams.

• Ability to make architecture-aware trade-offs across speed, quality, coupling, security, resilience, auditability, cost, and long-term maintainability.

• Demonstrated proactive approach to identifying integration risks, operational gaps, data-consistency risks, security concerns, and downstream system impacts.

• Experience with CI/CD, automated testing, environment promotion, release management, code review, secure development practices, and production change controls.

• Demonstrated experience designing enterprise integration layers that decouple digital channels from core systems.

• Proven experience implementing Backend-for-Frontend, orchestration, proxy, abstraction, or anti-corruption-layer patterns at scale.

• Experience in regulated or high-trust environments (e.g., financial services, healthcare) is an asset

• Experience integrating with Telus pension admin systems (Ariel), Microsoft CRM Dynamics, calculation engines, or similar legacy enterprise platforms is an asset.