Senior Full Stack Software Developer

Job Summary:

The Senior Full Stack Software Developer will support the Enterprise Pub/Sub Applications Team by developing and enhancing applications that integrate with the Agency s Enterprise Pub/Sub service based on FHIR Subscription and SubscriptionTopic. This role involves designing event-driven clinical workflows, replacing polling with subscription-driven event processing, and developing backend, serverless, interface, and user-interface components using Java, Node.js, AWS Lambda, React, and NextGen Connect (Mirth) for HL7 v2 integration.

Responsibilities:

• Assess polling-based integrations and map workflows to appropriate FHIR SubscriptionTopic and Subscription behaviors.
• Define, implement, and maintain SubscriptionTopic resources including triggers, filters, notification shapes, and conformance requirements.
• Manage subscription lifecycle including creation, validation, activation, status management, renewal, and deactivation.
• Design, develop, test, and support Java and Node.js services for event publishing, subscription management, notification consumption, and workflow routing.
• Develop AWS Lambda functions and queue-based integrations for asynchronous event processing and downstream updates.
• Implement reliable processing controls such as idempotency, retries, dead-letter handling, concurrency control, and replay mechanisms.
• Develop React applications utilizing SMART on FHIR for subscription-related workflows and secure FHIR API integration.
• Develop and maintain NextGen Connect (Mirth) channels for HL7 v2 message processing and integration with FHIR and Enterprise Pub/Sub events.
• Validate FHIR resources against definitions, profiles, terminology, and business rules.
• Implement observability features including logging, metrics, alerts, dashboards, and subscription health monitoring.
• Create comprehensive testing suites covering unit, integration, contract, conformance, regression, and performance tests.
• Ensure secure configuration, authentication, authorization, privacy-aware logging, and proper handling of personal health information.
• Prepare technical documentation, runbooks, and knowledge-transfer materials for project stakeholders.

Required Skills:

• Advanced expertise in FHIR Subscription and SubscriptionTopic including resource triggers, filters, lifecycle and status management, notification Bundles, delivery channels, heartbeat notifications, event retrieval, validation, and conformance testing.
• Senior-level development experience with Java and Node.js for REST APIs, FHIR integrations, event-driven workflows, and production application logic.
• Proficient in AWS Lambda and asynchronous queue processing with robust handling of retries, dead-letter queues, idempotency, concurrency, and event replay.
• Strong React development skills with SMART on FHIR launch, authorization, context, scopes, and FHIR API integration.
• Hands-on experience with NextGen Connect (Mirth), HL7 v2 integration, and Ontario digital health standards including Hospital Report Manager (HRM), Provider Registry, Client Registry, and eReferral.

Desired Skills:

• Experience with FHIR R5 Subscription model or backports for earlier FHIR versions, including rest-hook or websocket delivery.
• Familiarity with AWS messaging and observability services such as Amazon SQS, SNS, EventBridge, API Gateway, and CloudWatch.
• Knowledge of infrastructure as code, automated build and deployment pipelines, containerization, configuration management, and automated security scanning.
• Experience defining versioned FHIR profiles, event schemas, interface contracts, compatibility rules, and governance practices for enterprise integrations.
• Advanced skills in HL7 v2 message transformation, validation, routing, acknowledgements, error handling, conformance testing, and production support.

Rated Criteria:

• Advanced FHIR Subscription and SubscriptionTopic expertise - 25 Points
• Implementation experience with Java, Node.js, AWS Lambda, and asynchronous queues - 25 Points
• React and SMART on FHIR development skills - 25 Points
• NextGen Connect (Mirth) and HL7 v2 integration experience with Ontario digital health standards - 25 Points

Total: 100 Points Deliverables:

• FHIR SubscriptionTopic definitions and documentation of event triggers, filters, notification content, delivery expectations, and conformance rules.
• Subscription lifecycle management components including creation, validation, activation, renewal, deactivation, and heartbeat handling.
• Updated applications and workflows integrating Enterprise Pub/Sub event-driven processing replacing polling-based processes.
• Production-ready Java and Node.js services, APIs, event publishers, consumers, adapters, and integration components.
• AWS Lambda functions and queue-based processing components for validation, enrichment, retries, dead-letter handling, and replay.
• React components implementing SMART on FHIR launch, authorization, context, scopes, and FHIR API interactions.
• NextGen Connect (Mirth) channels for HL7 v2 ingestion, transformation, validation, routing, acknowledgements, and error management.
• FHIR profiles, validation rules, event and interface mappings, contract and conformance tests, integration and end-to-end test evidence.
• Structured logs, metrics, alerts, dashboards, subscription health monitoring, audit records, reconciliation controls, incident diagnostics, and runbooks.
• Technical designs, API and interface specifications, workflow documentation, security notes, deployment instructions, demonstrations, release-support materials, and knowledge-transfer artifacts.

Must Haves:

• Advanced FHIR Subscription and SubscriptionTopic expertise including lifecycle and status management, notification Bundles, and conformance testing.
• Proven implementation experience with Java, Node.js, AWS Lambda, asynchronous queues, and robust event processing controls.
• Strong React and SMART on FHIR experience for secure and accessible user interfaces.
• Extensive NextGen Connect (Mirth) and HL7 v2 integration skills aligned with Ontario digital health standards and provincial services.

Public Sector Experience:

Must have