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title: Backend Development
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  icon: TbTerminal
---


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## Useful commands

These commands should be exectued from packages/twenty-server folder.
From any other folder you can run `yarn nx <command>` twenty-server.

### First time setup

```
yarn nx database:reset # setup the database with dev seeds
```

###  Starting the app

```
yarn nx start
```

### Lint

```
yarn nx lint
```

### Test

```
yarn nx test:unit
```

### Resetting the database

If you want to reset the database, you can run the following command:

```bash
yarn nx database:reset
```

:::warning

This will drop the database and re-run the migrations and seed.

Make sure to back up any data you want to keep before running this command.

:::

## Tech Stack

Twenty primarily uses NestJS for the backend. 

Prisma was the first ORM we used. But in order to allow users to create custom fields and custom objects, a lower-level made more sense as we need to have fine-grained control. The project now uses TypeORM. 

Here's what the tech stack now looks like. 


**Core**
- [NestJS](https://nestjs.com/)
- [TypeORM](https://typeorm.io/)
- [GraphQL Yoga](https://the-guild.dev/graphql/yoga-server)

**Database**
- [Postgres](https://www.postgresql.org/)

**Third-party integrations**
- [Sentry](https://sentry.io/welcome/) for tracking bugs

**Testing**
- [Jest](https://jestjs.io/)

**Tooling**
- [Yarn](https://yarnpkg.com/)
- [ESLint](https://eslint.org/)

**Development**
- [AWS EKS](https://aws.amazon.com/eks/) 