Digital Twin
A public product and focused backend engineering contribution connecting decision-ready views with profile, plan, notification, wearable-data, and recommendation workflows.
The product, the pressure, and the response.
Overview
The case study covers implemented software responsibilities only. It does not claim clinical outcomes, diagnostic capability, or medical advice, and it does not publish private implementation or operating details.
Context
The product needed a backend that could coordinate request-response APIs with scheduled and background work while keeping profile, plan, notification, and wearable-data responsibilities understandable.
Solution
Node.js and Express services use PostgreSQL for application data, with Redis and BullMQ supporting background jobs. Service boundaries cover profiles, diet and exercise plans, notifications, Fitbit processing, and meal and exercise recommendation workflows.
Leading backend contributor
Backend services for profiles, diet and exercise plans, notifications, Fitbit workers, and meal and exercise recommendation workflows.
Profile services
Create and maintain application profile data used by the product workflows.
Diet and exercise plans
Support plan creation and retrieval through dedicated backend services.
Notification workflows
Coordinate scheduled and event-driven notifications outside the main user request path.
Fitbit workers
Process wearable-data synchronization through background jobs.
Recommendation services
Provide meal and exercise recommendation workflows as application features, not medical advice.
Built in reviewable steps.
- 01
Define service boundaries
Separate profiles, plans, notifications, wearable processing, and recommendations into maintainable backend responsibilities.
- 02
Build the API layer
Use Node.js and Express to expose the application workflows and coordinate PostgreSQL persistence.
- 03
Move background work off-request
Use BullMQ and Redis for jobs such as Fitbit synchronization and notification processing.
- 04
Constrain the public account
Describe the verified engineering contribution without publishing private code or making medical claims.