Here is the POC of a monorepo built with nestjs and prisma used to expose several apps, relying on several databases.
You will need the following to use this POC :
| Item | Description | Documentation |
|---|---|---|
 nodejs |
Duh! | https://nodejs.org/en/ |
 Docker |
we will use docker to launch a postgres instance | https://www.docker.com/get-started |
 bun |
We will use bun as the package manager for this project | https://bun.sh/docs |
You may need to give execution permission to the entry point script file, that is responsible for creating our three databases:
chmod +x docker/pg-init-scripts/create-multiple-db.shLet's then use docker compose :
bun dockerbun dev:db# Hiking app (port 5001)
bun dev hiking-app
# Projects app (port 5002)
bun dev projects-appNow we can access the swaggers of our apps using the following urls:
bun run build| Database | Description |
|---|---|
| 🚀 Hiking app | This kiking app allows users to check and join hiking groups planning to do a walk on some trail. This app owns a database but also uses the Users database. |
| 🚀 Projects app | This projects app allows users to check contributions made to repositories. This app owns a database and also uses the Users database. |
| Database | Description |
|---|---|
| 🧩 Boostraper | The code necessary to create an app is defined there and shared between apps. |
| 🧩 Databases | The base prisma services are defined on this shared module. |
| 🧩 Decorators | Decorators used in all our apps. |
| 🧩 Filters | Filters used in all our apps. |
| 🧩 Pipes | Pipes used in all our apps. |
| 🧩 Rxjs | Rxjs helpers. |
| 🧩 Tests | Test related code. |
We have three databases:
| Database | Description |
|---|---|
| 👨 Users | Contains our users (duh). This database will serve as the single base of truth for everything user related in our apps. |
| 🏔️ Hiking | Database dedicated to the hiking backend service. |
| 🧳 Projects | Database dedicated to the projects backend service. |
Let's take a look at the schema:
