Job Title: Sr. Software Developer - Full Stack
Location: Toronto, ON
Work Mode: Hybrid (Onsite as needed basis)
Duration: 6 months contract
Description:
The Agency requires 2 Senior Full Stack Developers to support the Enterprise Pub/Sub Applications Team. The resources will update The Agency applications and associated workflows to integrate with the Agency Enterprise Pub/Sub service, which is based heavily on FHIR Subscription and SubscriptionTopic. The work will replace scheduled polling with subscription-driven event processing where appropriate so applications can respond when clinical information, referrals, reports, status changes, or other relevant events become available. The roles spans FHIR event architecture, backend, serverless integration, interface, and user-interface development. The resource will define and implement FHIR Subscription and SubscriptionTopic behaviour; build Java and Node.js services, AWS Lambda functions, and queue-based event-processing components; develop React applications that use SMART on FHIR; and configure NextGen Connect (Mirth) channels for HL7 v2 workflows. The work includes subscription lifecycle management, filtering, notification handling, application and workflow changes, testing, monitoring, and transition of existing polling processes.
Required Skills:
- Strong hands-on experience with FHIR Subscription and SubscriptionTopic, including topic definitions, resource triggers, filter criteria, subscription status and lifecycle, notification Bundles, delivery channels, heartbeat notifications, and event retrieval.
- Senior-level experience developing Java and Node.js services, REST APIs, FHIR integrations, event publishers and consumers, and production application logic.
- Strong experience implementing FHIR Subscription and SubscriptionTopic workflows with AWS Lambda and asynchronous queues, including notification Bundle handling, retries, dead-letter handling, idempotency, concurrency, duplicate-event handling, and replay.
- Strong React development experience building production applications that use SMART on FHIR launch, authorization, context, scopes, and FHIR API integration patterns.
- Hands-on experience with NextGen Connect (Mirth), HL7 v2 integration, and Ontario digital health standards and provincial services, including the Hospital Report Manager (HRM) Standard, Provider Registry, Client Registry, and eReferral, covering message transformation, validation, routing, acknowledgements, error handling, conformance testing, and production support.
Responsibilities:
- Assess polling-based integrations and workflows, identify the clinical or application events that should trigger notifications, and map each workflow to the appropriate FHIR SubscriptionTopic and Subscription behaviour.
- Define, implement, and maintain SubscriptionTopic resources, including supported resource triggers, event definitions, filter parameters, notification shapes, and conformance requirements.
- Implement Subscription creation, validation, activation, status management, renewal, deactivation, delivery configuration, heartbeat handling, event retrieval, and subscriber lifecycle controls.
- Design, develop, test, and support Java and Node.js services that publish events, manage subscriptions, consume notification Bundles, call FHIR APIs, and route resulting actions to application workflows.
- Develop and maintain AWS Lambda functions and queue-based integrations for asynchronous event processing, validation, enrichment, workflow coordination, and downstream application updates.
- Implement reliable processing controls for idempotency, duplicate detection, retries, dead-letter handling, controlled concurrency, ordering where required, reconciliation, replay, and recovery.
- Develop and support React applications that use SMART on FHIR to present subscription-related workflows, launch within supported contexts, obtain authorized FHIR access, and interact with FHIR resources and application APIs.
- Develop and maintain NextGen Connect (Mirth) channels that receive, transform, validate, route, and acknowledge HL7 v2 messages and connect those workflows to FHIR resources, application services, and Enterprise Pub/Sub events.
- Validate Subscription, SubscriptionTopic, notification Bundle, and related FHIR resource instances against the applicable FHIR definitions, The Agency profiles, terminology, and business rules.
- Implement event correlation, structured logging, metrics, alerts, audit records, subscription health monitoring, and operational dashboards so teams can trace processing across publishers, Enterprise Pub/Sub, subscribers, and downstream applications.
- Create and maintain unit, integration, contract, conformance, interface, regression, end-to-end, performance, and failure-recovery tests covering FHIR subscription workflows, backend services, serverless processing, HL7 v2, and React components.
- Apply secure configuration, authentication, authorization, least-privilege access, privacy-aware logging, and appropriate handling of personal health information, and prepare technical designs, mappings, runbooks, and knowledge-transfer materials with project stakeholders.
Desired Skills:
- Experience implementing the FHIR R5 Subscription model or the R5 subscription backport for earlier FHIR releases, including SubscriptionTopic, rest-hook or websocket delivery, status notifications, heartbeat notifications, and event retrieval.
- Experience with AWS messaging, integration, and observability services such as Amazon SQS, Amazon SNS, Amazon EventBridge, Amazon API Gateway, and Amazon CloudWatch.
- Experience with infrastructure as code, automated build and deployment pipelines, containerized workloads, configuration management, and automated security scanning.
- Experience defining versioned FHIR profiles, event schemas, interface contracts, compatibility rules, correlation identifiers, and governance practices for shared enterprise integrations.
- Experience using NextGen Connect (Mirth) to integrate with Ontario digital health standards and provincial services, including the Hospital Report Manager (HRM) Standard, Provider Registry, Client Registry, and eReferral, with hands-on responsibility for HL7 v2 transformation, validation, routing, acknowledgements, conformance testing, and production support.
Required Competencies:
- Advanced FHIR Subscription and SubscriptionTopic experience, including resource triggers, filter criteria, lifecycle and status management, notification Bundles, delivery channels, heartbeat notifications, event retrieval, validation, and conformance testing.
- FHIR Subscription and SubscriptionTopic implementation experience for event-driven clinical workflows, including topic and event design, subscription filters and lifecycle management, notification Bundle processing, asynchronous queue processing, idempotency, retries, dead-letter handling, duplicate-event handling, observability, replay, and production troubleshooting using Java, Node.js, and AWS Lambda.
- React and SMART on FHIR experience, including launch and authorization flows, scopes, context handling, FHIR API integration, accessible user-interface development, automated testing, and secure handling of clinical information.
- NextGen Connect (Mirth), HL7 v2, and Ontario digital health standards experience, including the Hospital Report Manager (HRM) Standard, Provider Registry, Client Registry, and eReferral, covering message transformation, validation, routing, acknowledgements, error handling, interface and conformance testing, production support, and integration with FHIR, Java, Node.js, or serverless components.
Rated Criteria:
- Advanced FHIR Subscription and SubscriptionTopic experience, including resource triggers, filters, lifecycle and status management, notification Bundles, delivery channels, heartbeat notifications, event retrieval, validation, and conformance testing. 25 Points
- Demonstrated FHIR Subscription and SubscriptionTopic implementation experience using Java, Node.js, AWS Lambda, and asynchronous queues, including topic and event design, subscription filters and lifecycle management, notification Bundle processing, idempotency, retries, dead-letter handling, duplicate-event handling, replay, observability, and production troubleshooting. 25 Points
- React and SMART on FHIR experience, including launch and authorization flows, scopes, context handling, FHIR API integration, accessible user-interface development, and testing. 25 Points
- NextGen Connect (Mirth) and HL7 v2 integration experience, including transformation, validation, routing, acknowledgements, error handling, interface testing, and integration with Ontario digital health standards and provincial services such as the Hospital Report Manager (HRM) Standard, Provider Registry, Client Registry, and eReferral. 25 Points
Total: 100 Points
