Overview
Komvoy is a vehicle rental marketplace connecting fleet owners and individual renters. I was the primary developer on both the NestJS backend and the React client, working under the guidance of a more senior technical lead.
Key Achievements
Real-time Systems
- Multiple Socket.IO gateways with JWT authentication on connection
- Delivering live updates to the correct users by room across several distinct domain areas
Notification System
- Fully architected multi-channel notification system built around the Strategy pattern
- Four channel strategies run simultaneously: WebSocket, Web Push, email, and SMS
- Notification persistence handled by a dedicated storage module with DynamoDB
User Profile and Verification
- Phone number verification via a provider factory (Twilio Verify / AWS SNS)
- Transactional emails via Nodemailer/SES with i18n-aware templates in EN/ES
Domain Workflow and Data Modelling
- Relational PostgreSQL schema with TypeORM covering users, vehicles, fleets, rentals, invoices, and more
- 80+ incremental migrations without data loss
- Core domain workflows progress through explicit state machines
Document Generation Pipeline
- Modular section registry, Handlebars templating, and Puppeteer PDF rendering
- Supports multiple document modes with conditionally included sections
Payment and Billing
- Full Stripe integration: Connect onboarding, PaymentIntents, security deposits, SEPA Direct Debit
- Idempotent webhook processing with HMAC-SHA256 verification
- Invoice generation with VAT calculation and fiscal numbering
Authorization
- CASL-based attribute access control with fine-grained permissions across 15+ resource types
- Enforced via NestJS guards on the backend and route guards on the frontend
Complex Frontend Forms
- Multi-step wizard interfaces built with React Hook Form and Zod
- Vehicle creation, fleet bulk operations, and rental management interfaces
- Real-time state driven by WebSocket events
Deployment and Cloud Infrastructure
- Docker multi-stage builds, ECR image pushes, ECS Fargate redeployments
- Infrastructure: RDS PostgreSQL, DynamoDB, ElastiCache/Redis, S3, ALB, Lambda, SES