CROSS-PLATFORM PRODUCT · TRADING EDUCATION · 2026—
FLOW
One product, four surfaces, one set of rules.
01 / Context
The problem
A learner who buys a course on the web expects it on their phone a second later. The moment access rules are written twice, the two surfaces start disagreeing about what someone paid for.
02 / Response
The product response
A monorepo where web, mobile and admin are separate applications over one API, one schema and one entitlement engine. Courses, subscriptions, one-time purchases and trading signals all resolve access through the same server-side rules.
03 / Contribution
My role
Architecture and full-stack implementation across the API, the web and admin applications, and the native mobile client. The repository is private.
04 / Architecture
How the pieces connect
- 01Next.js web and admin surfaces
- 02Expo iOS and Android client
- 03NestJS API and entitlement engine
- 04Prisma + PostgreSQL data layer
05 / Execution
The engineering challenge
Keeping one definition of what a user is entitled to while three clients, two purchase models and a payment provider all ask the question differently — and enforcing the answer on the server, never in the interface.
06 / Result
Outcomes & perspective
In development. Course delivery, subscriptions, one-time purchases and the admin control centre are implemented and covered by integration tests against a real PostgreSQL database. The product has not launched.
07 / Reflection
A lesson from the work
Shared business logic is what makes a cross-platform product one product. The moment mobile reimplements a rule, there are two products that merely look alike.
08 / Evidence
Evidence & scope
Source: private monorepo README, package manifests and application structure, inspected September 2026. Development status is taken from the project’s own release documentation.