Real-Time Emergency Dispatch · In production
NeoSaver
Production backend for an ambulance dispatch platform with real-time driver discovery, fare negotiation, GPS tracking and OTP-verified trips, plus an admin dashboard in development. The code is private.
My role: Backend Developer at NeoSaver (Bangladesh). Designed and built the backend from the ground up, and now building the admin dashboard.
Patient and driver apps, admin dashboard
AWS
EC2, Docker
Caddy
HTTPS reverse proxy
Spring Boot service
REST API, STOMP messaging, JWT and RBAC
PostgreSQL
RDS, Flyway migrations
Redis
ElastiCache for Valkey: cache, sessions, rate limiting
S3
File storage
Overview
NeoSaver connects patients in Bangladesh with nearby ambulance drivers. A patient chooses the ambulance type and equipment they need, sees the nearest available drivers and agrees a fare with one of them before the ride starts.
Drivers work on commission: the platform's share of each completed trip is recorded against the driver, and payment collectors settle those dues in cash. Admins oversee rides, drivers and payments, with an audit trail of every ride.
Key Features
- Nearest available drivers, filtered by ambulance type and equipment, with rating, distance and ETA
- Live fare negotiation, with up to three offers from each side before the ride is confirmed
- Pickup code to start the trip and a payment code to complete it
- Live driver location and ride status for the patient during the trip
- Emergency booking as a guest, so a first ride needs no sign-up
What I Built
- Modular Spring Boot architecture, designed and built from the ground up.
- STOMP over WebSockets for live bidding, trip-state sync, GPS tracking and notifications, plus Firebase push.
- PostgreSQL data model with versioned Flyway migrations.
- JWT with role-based access control, OTP verification and Redis for caching, sessions and rate limiting.
- Driver commissions, wallets and FIFO payment settlement.
- Runs on AWS (EC2, VPC, RDS, ElastiCache, S3, ECR) behind Caddy, with the whole account built in Terraform.
- CI/CD with GitHub Actions: tests on every push, then a deploy through SSM that rolls back automatically if the health check fails.
- Tests with JUnit, Mockito and Testcontainers, running repository tests against a real PostgreSQL.
- Next.js admin dashboard in development: sign-in for admins, super admins and payment collectors and live notifications over STOMP are in place.
Built With
- Java 21
- Spring Boot
- PostgreSQL
- Redis
- WebSockets
- AWS
- Terraform
- Docker
- GitHub Actions
- Spring Security
- Flyway
- Next.js