The engineering problemBring drafting workflows to iOS/Android.
A music-generation product needed web, mobile, AI orchestration, domain logic, and release controls to evolve without each client inventing its own contracts or failure behavior.
Component responsibilityWhat this part of the system owns
Owns the native mobile flow, device state, shared transport, and mobile verification surface.
This is a real multi-surface product architecture: independently deployable clients and API services share typed contracts and domain packages, with explicit quality and performance gates.
- Primary platform
- Mobile
- Interface
- Expo React Native
- System relationship
- Chord Draft / aJam
- Priority
- Flagship
Operating flowHow inputs become controlled outputs
Inputs- User music intent and session state
- Typed generation requests
- Catalog and knowledge context
System behavior- Validate shared request contracts
- Orchestrate generation and domain tools through the API
- Return explicit success or failure states to web and mobile clients
Outputs- Structured jam results
- Interactive web and mobile sessions
- Operational health and performance signals
Why the solution is shaped this way
Keep web and mobile clients separated from the agent API by HTTP.
Why: Clear deployment boundaries let clients evolve independently while sharing one service contract.
Tradeoff: Contract changes require coordinated schema versioning and compatibility checks.
Put shared schemas and domain behavior in packages rather than sibling applications.
Why: One implementation of request shapes and music-domain rules reduces client drift.
Tradeoff: Package ownership and dependency direction must remain disciplined.
Fail explicitly in live AI mode instead of silently substituting demo output.
Why: Users and operators can distinguish provider failure from a genuine generated result.
Tradeoff: Availability is lower than a silent fallback, but product behavior is more trustworthy.
How the solution is structured and verified
Solution shape
- Next.js web application
- Hono/Node agent API
- Expo React Native client
- Shared contracts, domain tools, HTTP client, knowledge, and runtime configuration packages
Framework and package signals
- Next.js
- Node.js with Hono
- Expo / React Native
- TypeScript
- Zod contracts
- LangGraph and OpenAI orchestration
- Supabase
- Upstash Redis
- OpenTelemetry
Executable surfaces
- Browser product
- Mobile application
- HTTP API
- Local evaluation and benchmark commands
Verification
- Package and application unit tests
- API smoke, evaluation, benchmark, model-routing, and performance guardrail commands
- Playwright route, critical-flow, visual, release, and post-deployment suites
- Mobile verification and shared-contract tests
What Thomas built
Thomas designed and implemented the coordinated product system, including its application boundaries, shared packages, delivery rules, and verification surfaces.
Technical compositionTechnologies, logic, and connected outputs
TypeScriptJavaScriptNext.jsNode.jsExpo React NativeLangGraphOpenAITurbopnpmMobile
Algorithms and domain rules
- Mobile interaction and synchronization
Integrations and data
- OpenAI
- web/mobile clients
- telemetry
- Environment/provider dependent
Outputs and runtime
- Expo React Native
- Mobile Application
- Vercel
- Railway
- EAS
Libraries and architecture
- Expo React Native
- Next.js
- Node.js
- LangGraph
- OpenAI
- Turbo
- pnpm
- TypeScript
- Playwright
- OpenAI/LangGraph ecosystem
What an evaluator can inspect
Confidence: High. This portfolio distinguishes delivered applications, supporting components, tests, libraries, utilities, and repository containers.
The implementation summary was derived from reviewed solution files, project or package manifests, architecture documentation, and test surfaces. Private locators, source code, secrets, and proprietary rules are not published.
- Repository overview and production ownership (readme)
- Workspace and application manifests (manifest)
- Architecture decision record (architecture)
- System architecture and generation-flow documentation (architecture)
- Unit, browser, evaluation, benchmark, and performance gates (tests)
- Private source locations, customer data, proprietary rules, and raw implementation material are withheld.
Portfolio source review
The public record summarizes application purpose and composition. Private paths, source, customer data, proprietary rules, and restricted artifacts are not published.
