# El hadj Arroyo - FULLSTACK DEVELOPER
Source: https://hello.cv/komvoy-test-adminkomvo
Madrid

## Links
- LinkedIn | https://linkedin.com/in/elhadjarroyo
- GitHub | https://github.com/arroyostack
- X | https://twitter.com/elhadj-Komvoy
- Email
- Phone

## About
Fullstack developer with professional experience across the full<br>stack of a production vehicle rental marketplace — backend and<br>frontend, from architecture and data modelling through to real-time<br>systems, payment integrations, and deployment. Before that I spent<br>two years as a freelance developer building websites and small<br>applications for local businesses.<br>I am looking to join a strong team where I can keep growing. I take<br>ownership of what I build and pick things up quickly.

## Work
### Fullstack Developer | Komvoy
As the primary Fullstack Developer at Komvoy, I engineered and deployed critical backend and frontend systems for a production vehicle rental marketplace, delivering real-time functionality and robust integrations.
- Engineered multiple Socket.IO gateways with JWT authentication, delivering secure, live updates to users across distinct domain areas, significantly enhancing real-time user interaction and data synchronization.
- Architected and implemented a multi-channel notification system leveraging the Strategy pattern, featuring retry logic, exponential backoff, and DynamoDB persistence across WebSocket, Web Push, email, and SMS channels for reliable user communication.
- Designed and evolved a robust relational PostgreSQL schema with TypeORM, overseeing 50+ incremental migrations without data loss and implementing explicit state machines for core domain workflows, ensuring data integrity and system scalability.
- Integrated comprehensive Stripe Connect for payment and billing, managing payment intent lifecycles, secure deposit handling via state machines, SEPA recurring payments with retry logic, and idempotent webhook processing, supporting diverse invoice generation.
- Managed and deployed scalable cloud infrastructure using Docker, ECR, ECS Fargate, and CloudFormation, ensuring high availability and performance for critical services including RDS, DynamoDB, ElastiCache, S3, ALB, Lambda, and SES.
### Freelance Web Developer | Self-employed
Operated as a Freelance Web Developer, independently delivering bespoke websites and web applications for local businesses and individual clients from requirement gathering to deployment.
- Developed and launched custom websites and small web applications for diverse clients, translating complex requirements into intuitive user interfaces and functional digital solutions.
- Managed end-to-end project lifecycles, including client consultation, UI/UX design, development, and deployment, ensuring timely delivery and client satisfaction.
- Cultivated strong client relationships through effective communication and transparent project management, consistently delivering products that met specific business needs.
- Gained foundational expertise in frontend development and version control best practices, ensuring robust and maintainable codebases for all projects.

## Education
### 4Geeks Academy | FullStack Development
### London South Bank University | Music and Sound for the Media
First Class Honours (1:1)

## Languages
- Spanish
- English

## Skills
### Backend Development
- Node.js
- NestJS (modular architecture, guards, interceptors, decorators)
- TypeScript
- Use-Case / Clean Architecture
### Databases
- PostgreSQL (via TypeORM, migrations, relations, query builder, 80+ migrations)
- DynamoDB (AWS SDK v3)
- Redis (ElastiCache)
### Auth & Access
- JWT (custom strategy + refresh tokens)
- Passport.js (Google OAuth, Facebook OAuth)
- CASL (attribute-based access control)
### Real-Time Systems
- Socket.IO (rentals gateway, fleet gateway, vehicle gateway, chat gateway, notifications gateway)
### Payments
- Stripe (Connect, PaymentIntents, SEPA Direct Debit, idempotent webhooks, HMAC validation, DepositStateMachine)
### Notifications
- Nodemailer + AWS SES
- AWS SNS
- Twilio (SMS + verification)
- Web Push (VAPID service worker)
### Files & Media
- AWS S3 (upload, signed URLs)
- Cloudinary
- Sharp (image processing)
- Puppeteer + Handlebars (PDF generation)
### Frontend Development
- React 18
- TypeScript
- Vite
- TanStack Router (file-based, route guards)
- TanStack Query
- Zustand (domain-split stores)
### Forms & UI
- React Hook Form
- Zod (multi-step wizards)
- Material UI v5 (custom theme)
- Stripe Elements
- MapLibre GL JS
### I18N & Testing
- i18next (EN/ES runtime switching)
- Playwright (E2E)
- Vitest
- Jest (unit - use cases, controllers, services)
### DevOps / Cloud
- AWS ECS Fargate
- ECR
- RDS
- DynamoDB
- ElastiCache
- S3
- CloudFront
- ALB
- Lambda
- SES
- Secrets Manager
- CloudWatch
- CloudFormation
### CI/CD & DX
- Docker (multi-stage builds)
- GitHub Actions (15+ workflows)
- Husky
- Commitlint
- ESLint
- Prettier
- Semgrep (SAST)
### Patterns
- Strategy (notification channels, SMS clients, payment gateways)
- Observer (WebSocket fan-out)
- State Machine (deposit, rental transitions)
- Factory
- Clean Architecture

## Source
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