@loopback/docs/site/Best-practices-with-Loopback-4.md

Documentation for LoopBack 4

---
lang: en
title: 'Best practices with Loopback 4'
keywords: LoopBack 4.0, LoopBack 4
tags:
sidebar: lb4_sidebar
permalink: /doc/en/lb4/Best-practices-with-Loopback-4.html
summary:
---

{% include important.html content=" The API-first approach for building LoopBack
applications is not yet fully supported. Therefore, some of the sections in this
page are outdated and may not work out of the box. They will be revisited after
our MVP release.
" %}

LoopBack 4 is more than just a framework: It’s an ecosystem that encourages
developers to follow best practices through predefined standards. This section
will walk through some important guidelines by building an example API for a
catalog of products.

Our best practice follows an "API first" and test-driven development approach:

1. **Defining the API**: There are two possible approaches to take in this
   section
   - [**Defining the API using code-first approach**](./Defining-the-API-using-code-first-approach.md):
     This section guides you through setting up a skeleton of your application
     so that its full OpenAPI specification can be automatically generated.
   - [**Defining the API using design-first approach**](./Defining-the-API-using-design-first-approach.md):
     This section guides you through constructing your API first before any
     internal logic is added. **_Not fully supported_**
     - [**Testing the API**](./Testing-the-API.md): This section describes the
       process of writing smoke test for your API and its spec. **_Not fully
       supported_**
2. [**Defining your testing strategy**](./Defining-your-testing-strategy.md):
   This section discusses the advantages and the process of building a strong
   testing suite.
3. [**Implementing features**](./Implementing-features.md): This section
   demonstrates how the tests for each feature of your application should be
   written, and how to write the logic to make these tests pass. In the
   example, the tests for the controller, model, repository, data source, and
   sequence are written and then implemented.
4. [**Preparing the API for consumption**](./Preparing-the-API-for-consumption.md):
   This section shows how the endpoints can be physically tested using the
   Swagger UI.