Backend Developer

Electronic Medical Record

Multi-tenant clinic & hospital SaaS

2024 — 2026·5 engineers

clinics on one platform

0k+

patient records

faster record retrieval

0.0%

uptime

Overview

A multi-tenant SaaS platform for clinic and hospital management covering patient registration, queue management, consultations, medical records, billing, and secure document storage — serving 12 clinics on shared infrastructure with strict tenant isolation.

Challenges

Enforcing tenant isolation for sensitive medical data across every API and background job.
Medical record search slowing down as records grew past tens of thousands.
Handling large medical documents without bloating the transactional database.

Solutions

Designed multi-tenant RBAC for doctors, nurses, clinic admins, and staff with tenant-scoped guards on every route and worker.
Redesigned PostgreSQL schemas, indexes, and query patterns for record search and retrieval paths.
Moved documents to MinIO object storage with signed access flows, keeping only metadata in PostgreSQL; RabbitMQ workers handle long-running tasks.

Results

Record search and retrieval ~40% faster after schema and index redesign.
12 clinics and 50k+ patient records with zero cross-tenant data incidents.
99.9% uptime with blocking work moved off the request path.

Architecture

Tech stack

NestJS
PostgreSQL
Redis
RabbitMQ
MinIO
RBAC
Docker
AWS

Process

01
Domain modeling
2 weeks
Mapped clinic workflows, tenants, roles, and record lifecycles.
02
Backend development
18 months
APIs, RBAC, storage integration, background workers.
03
Hardening
Continuous
Tenancy edge cases, performance passes, audit reviews.

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