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# GDGoC UAM Website
[GitHub](https://github.com/GDG-UAM/website-refactor) | [Live Demo](https://gdguam.es)
**Date:** August - December 2025
**Technologies:** Node.js, Elysia.js, MongoDB, Next.js, Tailwind CSS, TypeScript, React, Redis, Gemini, OpenBadges, Framer Motion, Sentry, Better Stack, Better Auth
---
## Project Overview
The GDGoC UAM website is a full-stack platform built for the Google Developer Group on Campus at Autonomous University of Madrid. It serves as the organization's public face, administrative backbone, and event management hub. The project replaces a static landing page with a dynamic system capable of handling blog articles, event listings, certificate generation, hackathon management, team evaluations, and real-time audience interactions.
The architecture separates concerns into a Next.js frontend (App Router) and an Elysia.js backend with MongoDB. This split allows the frontend to prioritize SEO, internationalization, and progressive enhancement while the backend handles complex business logic, granular permissions, and real-time WebSocket communication. The platform supports Spanish and English natively, with content stored as locale-keyed objects rather than separate documents, eliminating synchronization headaches.
What started as a simple event site grew into a multi-domain application with admin panels, certificate templates, evaluation rubrics, and a custom markdown pipeline. The codebase is organized as a monorepo using Bun workspaces, with shared packages for permissions and type definitions.
## Technical Stack
### Backend
- **Runtime**: Bun with TypeScript
- **Framework**: Elysia.js with Eden Treaty for end-to-end type safety
- **Database**: MongoDB with native driver (no ODM), using repository pattern
- **Authentication**: Better Auth with Google OAuth 2.0, Redis-backed session cache
- **Permissions**: Custom `@gdg-uam/permissions` package with CASL-inspired ability builder
- **Real-Time**: Elysia WebSocket plugin for hackathon intermission screens
- **Email**: Resend API for transactional emails
- **Image Processing**: Sharp for BlurHash generation and image metadata extraction
- **Caching**: Redis with ioredis, prefixed keys, and automatic session invalidation
### Frontend
- **Framework**: Next.js 15 App Router with React Server Components
- **Styling**: Tailwind CSS with styled-components for component-scoped styles
- **Animations**: Framer Motion for page transitions, layout animations, and carousel effects
- **State Management**: React Context for settings, toasts, breadcrumbs, and permissions
- **Internationalization**: Paraglide with inlang project for compile-time message extraction
- **Markdown**: Custom rendering pipeline with syntax highlighting, embeds, audio players, and user mentions
- **Forms**: React Hook Form with Zod validation
- **Accessibility**: Respects motion/contrast preferences, does runtime changes without re-renders and a floating action button exposes controls to users that are not logged in
### DevOps
- **Monorepo**: Bun workspaces with Turbo for task orchestration
- **Containerization**: Multi-stage Docker builds for both frontend and backend
- **CI/CD**: GitHub Actions with Buildx, cosign image signing, and ghcr.io registry
- **Monitoring**: Sentry and Better Stack for error tracking and performance monitoring
- **Code Quality**: ESLint with TypeScript, Husky pre-commit hooks (type-check, tests, lint-staged)
## Architecture Highlights
### Repository Pattern with Native MongoDB
Rather than using Mongoose or Prisma, the backend implements a pure repository pattern over the native MongoDB driver. Each entity (articles, events, hackathons, teams, certificates) has a dedicated repository class that encapsulates collection access, index creation, and query logic. This eliminates ODM overhead and gives full control over aggregation pipelines.
Repositories are initialized lazily on first database connection and cached globally to survive hot reloads in development:
```typescript
const repositoryCache: RepositoryCache =
global.repositories ||
(global.repositories = {
userRepository: null,
articleRepository: null
// ...
});
```
Cross-repository dependencies are resolved after initialization. For example, `CertificateTemplateRepository` receives `CertificateRepository`, `HackathonRepository`, `TeamRepository`, and `UserRepository` via constructor injection, then calls `setTemplateRepository` on `HackathonRepository` and `TeamRepository` to establish bidirectional synchronization hooks.
### Granular Permission System
The `@gdg-uam/permissions` package implements a custom ability builder inspired by CASL but tailored for the project's resource hierarchy. Permissions are evaluated at three levels:
1. **Base permissions**: Every authenticated user gets read access to public resources
2. **Global role-based permissions**: `organizer` and `admin` roles bypass all checks
3. **Fine-grained permissions**: Individual and template permissions stored on the user document
Permissions use a resource string format like `admin.hackathons.{id}.teams.{teamId}.certificates.{certId}`, with field-level granularity for updates. The `AbilityBuilder` constructs MongoDB-compatible query predicates that can be passed directly to repository methods.
Session permissions are cached in Redis and invalidated automatically when roles, templates, or individual permissions change. The `updateUserSessions` function iterates over all session keys belonging to a user and refreshes the cached user object, preserving TTLs.
### Redis-Backed Session Cache
Better Auth's secondary storage is wired to Redis for production environments. The `set` hook extracts `userId` from session data and tracks which keys belong to which user via Redis sets (`user-sessions:{userId}`). This enables targeted session invalidation without flushing the entire cache.
The session cache is disabled in development to simplify debugging, and cookie caching is disabled globally due to complex JSON fields exceeding cookie size limits.
### Custom Markdown Pipeline
Articles and events are authored in Markdown but require rich media support. The backend processes markdown on save, converting `` syntax into custom `` tags with precomputed BlurHash strings, dimensions, and optional titles. On edit, the reverse transformation restores standard markdown for the admin editor.
The frontend renders `` tags with lazy loading, blur-to-sharp transitions, and responsive sizing. Additional markdown extensions include:
- **Audio players** with waveform visualizers
- **Iframe embeds** with sandboxed security
- **User mentions** that resolve to profile cards
- **Syntax highlighting** with language detection
See the [Highly Customized Markdown Editor](/projects/gdguam/website/custom-markdown) for detailed technical documentation.
### Certificate Template Engine
Certificates can be generated individually or from templates linked to hackathons and teams. The template engine resolves default values from the parent hackathon (design ID, title, signatures, dates) and team membership (recipient list). When a template is created or updated, the system automatically generates or updates individual certificate documents, deleting certificates for removed recipients.
The `CertificateRepository.findById` method uses an aggregation pipeline with `$lookup` joins against `certificatetemplates` and `hackathons`, then applies `$ifNull` chains to resolve fallback values. This allows certificates to inherit properties from templates while still permitting overrides.
### Real-Time Hackathon Intermission
Hackathon intermission screens display sponsor logos, schedules, and custom carousels to participants between sessions. The backend exposes a WebSocket endpoint at `/hackathons/:slug/intermission/ws` that subscribes clients to a topic. When an admin updates the intermission configuration via PATCH, the backend publishes the new data to all connected clients.
The intermission carousel editor in the admin panel uses a tree-based component system where each slide is a nested structure of containers, text blocks, images, QR codes, and spacers. The frontend renders this tree recursively with responsive scaling and theme-aware colors.
### Internationalization with Paraglide
The frontend uses Paraglide for compile-time internationalization. Messages are extracted from source code and stored in the `messages/` directory, with the `project.inlang` configuration defining supported locales. The `localePlugin` on the backend reads the `PARAGLIDE_LOCALE` cookie to determine the user's preferred language, returning localized content from locale-keyed database fields.
Content models store translations as `Record` maps. The backend uses `$ifNull` aggregation stages to fall back through `requestedLocale → es → first available`, ensuring content is always served even when a specific translation is missing.
### CSRF Protection
The backend implements CSRF protection via double-submit cookie pattern. A `/csrf` endpoint initializes an `XSRF-TOKEN` cookie (readable by JavaScript, `SameSite=lax`). All mutating requests must include the same token in the `x-xsrf-token` header. Internal server-to-server calls bypass validation using a shared `x-internal-secret` header.
### Admin Panel Architecture
The admin panel is a sub-application within the Next.js frontend, mounted under `/admin`. It uses a consistent layout with breadcrumbs, navigation sidebar, and form builders. Admin pages are generated dynamically from repository schemas, with reusable components for tables, forms, and field editors.
The `AdminTable` component supports sorting, pagination, search, and bulk actions. The `AdminFormBuilder` renders form fields from schema definitions, handling nested objects, arrays, and file uploads. Form submissions are validated with Zod schemas shared between frontend and backend.
## Accessibility
The site supports four accessibility modes applied via `data-*` attributes on `document.documentElement` before React hydrates:
- **Reduced motion** (disables Framer Motion and CSS transitions)
- **Dyslexic font** (switches to OpenDyslexic with increased letter and word spacing)
- **High contrast** (reads `prefers-contrast: more` as fallback)
- **Color blindness correction** (deuteranopia, protanopia, tritanopia via SVG filter matrices)
Settings persist identically for logged-in users (backend sync) and anonymous visitors (`localStorage` read by a blocking script to prevent FOUC), with a floating action button exposing the same controls to guests without requiring navigation to `/settings`.
---
## Sub-Projects in this Folder
- **Certificate System** ([/projects/gdguam/website/certificate-system.md](https://tablerus.es/projects/gdguam/website/certificate-system.md))
- **Automatic AI Translations** ([/projects/gdguam/website/ai-translations.md](https://tablerus.es/projects/gdguam/website/ai-translations.md))
- **Highly Customized Markdown Editor** ([/projects/gdguam/website/custom-markdown.md](https://tablerus.es/projects/gdguam/website/custom-markdown.md))
- **Automatic Blurhash System** ([/projects/gdguam/website/custom-markdown/auto-blurhash.md](https://tablerus.es/projects/gdguam/website/custom-markdown/auto-blurhash.md))
- **Custom Embeds** ([/projects/gdguam/website/custom-markdown/embeds.md](https://tablerus.es/projects/gdguam/website/custom-markdown/embeds.md))
- **Custom Audio Player** ([/projects/gdguam/website/custom-markdown/audio-player.md](https://tablerus.es/projects/gdguam/website/custom-markdown/audio-player.md))
- **User Mentions** ([/projects/gdguam/website/custom-markdown/user-mentions.md](https://tablerus.es/projects/gdguam/website/custom-markdown/user-mentions.md))
- **Advanced Feature Flag System** ([/projects/gdguam/website/feature-flag-system.md](https://tablerus.es/projects/gdguam/website/feature-flag-system.md))
- **Real-Time Giveaway System** ([/projects/gdguam/website/giveaway-system.md](https://tablerus.es/projects/gdguam/website/giveaway-system.md))