https://github.com/DieGomezR/sr-fullstack-challenge/pull/new/feature/logistics-notification-hub

[DieGomezR]

Summary

This PR implements the challenge as a small real-time logistics notification system.

The solution includes:

• a Next.js app with App Router
• a separate Bun service for notifications and WebSocket fanout
• SQLite persistence
• a real-time dashboard for operations
• Docker Compose to run the full stack

What I built

API

• POST /api/notifications
• GET /api/notifications
• GET /api/channels

The API validates input, returns consistent responses, and forwards notification creation to the Bun hub.

Bun notification hub

The Bun service is responsible for:

• storing notifications in SQLite
• serving filtered notification queries
• managing WebSocket subscriptions by channel
• broadcasting new notifications to subscribed clients
• exposing a /health endpoint

Frontend

The UI is a single-page dashboard that:

• connects to the WebSocket server
• shows connection state
• displays notifications in real time
• supports filtering by channel and priority
• allows creating notifications from the UI

I started with a simpler dashboard and then refactored it into smaller panels before doing the final visual pass.

Architecture / decisions

I kept the Next.js API and the Bun hub as separate responsibilities.

Next.js handles:

• the user-facing app
• the public API routes
• request validation and response formatting

The Bun service handles:

• persistence
• real-time fanout
• subscription management

I chose SQLite because it fits the scope of the challenge well and keeps the project easy to run locally.

I also kept the communication between Next.js and the Bun service simple through internal HTTP calls instead of introducing a queue or pub/sub layer for this time box.

Frontend notes

The dashboard was redesigned with shadcn/ui components and a HextaUI-inspired layout after the functional version was working.

I also split the dashboard into smaller components to improve readability and separation of concerns, since the initial implementation was growing too large.

Docker / Bun note

The challenge requires Bun, so the solution keeps Bun in the runtime path for both:

• the notification hub
• the Next.js app execution flow

For the app scripts I used:

• bun --bun next dev --webpack
• bun --bun next build --webpack
• bun --bun next start

I switched the Next.js build path away from the Turbopack path because Bun was hitting unsupported worker_threads options in this environment.

I also removed the dependency on Google Fonts at build time so Docker builds do not fail when external font fetches are blocked.

Validation

I validated the project locally with:

• npm run lint
• npm run typecheck
• next build --webpack

Trade-offs

A few things I would improve with more time:

• add auth / access control for an internal tool
• add integration or E2E tests
• add better observability around WebSocket lifecycle and failures
• add a queue or pub/sub layer if this needed to scale beyond a single hub instance

AI usage

I used Codex/ChatGPT in parts of the implementation, refactoring, and review process.