Formulary - Medicine Substitution Platform

Overview

Formulary is a backend-driven healthcare platform that enables users to search medicines, discover equivalent substitutes, and compare prices to identify cost-effective alternatives.

The system is designed as a read-heavy, high-performance API, optimized using caching and efficient database querying.

Problem

Patients often pay higher prices for branded medicines due to lack of visibility into cheaper substitutes with identical compositions.

Solution

Formulary provides:

• Fast medicine search
• Substitute discovery using composition-based mapping
• Price comparison across equivalent medicines
• Admin-controlled data management with bulk uploads

Tech Stack

• Frontend: React, TailwindCSS
• Backend: Node.js, Express
• Database: PostgreSQL
• Caching: Redis
• Containerization : Docker, Docker Compose
• CI/CD : GitHub Actions

Performance Improvements (Redis Caching)

To handle a read-heavy load, we implemented a robust Redis caching layer on our search and substitute APIs.

Endpoint	Before (DB)	After (Cache)	Improvement
Search	~80–200 ms	~7–12 ms	~85% faster
Substitutes	~120 ms	~10–20 ms	~80% faster

Before Redis (Direct DB Queries)

After Redis (Cache Hits)

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Installation & Setup

1. Clone the repository

git clone https://github.com/CodeByAshuu/formulary.git
cd formulary

2. Setup the Backend

cd server
npm install

• Create a .env file in the server directory with your Postgres and Redis credentials.

PORT=5000
DB_USER=postgres
DB_PASSWORD=password
DB_NAME=formulary_db
DB_HOST=localhost
DB_PORT=5432
REDIS_URL=redis://localhost:6379
JWT_SECRET= your_secret_key
ADMIN_PASSWORD=admin
ADMIN_EMAIL=admin@example.com

• Seed the database (if applicable) and start the server:

npm run dev

3. Setup the Frontend

cd ../client
npm install
npm run dev

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How to use Redis (Two Ways)

The application utilizes Redis to cache API responses. You can run Redis locally either by installing it directly or by using Docker.

Method 1: Using Docker (Recommended)

Running Redis via Docker ensures a clean environment without system-level installations.

1. Ensure Docker is installed and running on your machine.
2. Run the following command to start a Redis container:

   docker run -d --name formulary-redis -p 6379:6379 redis

3. The server will automatically connect to redis://localhost:6379.
4. Open Redis CLI inside container

   docker exec -it formulary-redis redis-cli

5. Clear Cache (everything)

    FLUSHALL

Method 2: Native Redis Server (Windows/Mac/Linux)

1. Windows: Install using WSL (Windows Subsystem for Linux) and run:

   sudo apt-get install redis-server
   sudo service redis-server start

   Alternatively, download the pre-compiled Windows port of Redis from GitHub.
2. Mac: Use Homebrew:

   brew install redis
   brew services start redis

3. Linux: Use your package manager (e.g., APT):

   sudo apt install redis-server
   sudo systemctl start redis-server

Once running locally, the application will automatically connect to the default port 6379.

Key Features

• High-performance search with indexing
• Redis caching with TTL and invalidation
• Bulk CSV upload for medicines
• Automatic substitute linking using composition
• Secure admin APIs with JWT authentication
• Containerized deployment

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CI/CD

• CI pipeline:

  • Linting + dependency install
  • PostgreSQL + Redis service containers
  • Backend smoke test

• CD pipeline:

  • Docker image build
  • Push to GitHub Container Registry (GHCR)

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Future Improvements

• Fuzzy search (typo tolerance)
• Advanced filtering (price range, manufacturer)
• Rate limiting
• Observability (logs, metrics)

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Author

Sagar Sahu