---
title: "Expert path"
description: "8 lessons for developers and agencies: Éclair CMS architecture, testing, templates, Nginx, performance, WordPress migration, security and production."
url: "https://eclair.academy/en/paths/expert"
lang: "en"
author: "Thierry Gustin"
published: "2026-11-02"
updated: "2026-11-02"
---

# Expert path

> **Key takeaways** — The Expert path is for developers and agencies deploying Éclair CMS. In 8 lessons, you understand its database-free architecture, develop and test locally, customize the templates, host it on Nginx, migrate WordPress sites and scale up production.

## Deploy Éclair at scale

Eight technical lessons for developers and agencies: understand Éclair from the inside, host it anywhere, migrate existing sites and deliver client sites with no plugin maintenance.

[Start lesson 1](https://eclair.academy/en/paths/expert/architecture)

This path is for developers, integrators and web agencies. It assumes you're comfortable with PHP, the command line and a web server. Every command and class name mentioned exists in the Éclair 1.8 code.

## What you'll be able to do

### 🛠 Master the code

Read the life of a request, flat-file storage and the main classes, then test locally.

### 🚀 Deploy anywhere

Configure Nginx, a VPS, a proxy, a CDN or a Docker container, while keeping 100 out of 100.

### 👥 Scale up

Migrate existing sites, maintain a fleet of sites and organize agency production.

## The 8 lessons for developers and agencies

1. [Éclair's architecture](https://eclair.academy/en/paths/expert/architecture) The front controller, the static cache served without loading the application, and storage in data/.
2. [Local development and testing](https://eclair.academy/en/paths/expert/local-development) PHP's built-in server, automated tests, the distribution archive and debug mode.
3. [Customize the theme templates](https://eclair.academy/en/paths/expert/theme-customization) The files in app/theme, their variables, security constraints and this academy's example.
4. [Nginx, VPS, proxy and CDN](https://eclair.academy/en/paths/expert/nginx-vps) The official Nginx configuration, PHP-FPM, Cloudflare and a Docker example to adapt.
5. [Performance: staying at 100 out of 100](https://eclair.academy/en/paths/expert/performance) What Éclair already optimizes, how to measure and what not to add.
6. [Migrate from WordPress or Wix](https://eclair.academy/en/paths/expert/migrate-wordpress) The URL inventory, content transfer, 301 redirects and the switchover.
7. [Advanced security and maintenance](https://eclair.academy/en/paths/expert/advanced-security) The security review, updates, access recovery and off-site backups.
8. [Scaling Éclair in an agency](https://eclair.academy/en/paths/expert/agencies) Production process, client accounts, maintenance plans and the MIT license.

> **Before you start** — Having followed the [Beginner path](https://eclair.academy/en/paths/beginner) helps you connect the admin with the code. Éclair's commented sources are public on [GitHub](https://github.com/Jacckisback/eclair-cms): keep them open next to the lessons.

## Why does Éclair appeal to agencies?

An Éclair site has no database to back up and no plugins to update every week. It weighs under 1 MB, deploys by copying a folder and moves to a new address by changing one URL in the settings. For an agency, that means a fleet of fast, secure sites whose maintenance comes down to the essentials.

## Questions about the Expert path

### Can I modify Éclair's code freely?

Yes. Éclair is under the MIT license: you can modify and redistribute it, including for commercial use, as long as you keep the copyright notice. The [Customize the theme templates](https://eclair.academy/en/paths/expert/theme-customization) lesson explains how to do it without losing your changes when you update.

### Does Éclair work without Apache?

Yes. On Nginx, you just need to reproduce the rules of the .htaccess file. The complete configuration is in the [Nginx, VPS, proxy and CDN](https://eclair.academy/en/paths/expert/nginx-vps) lesson.

### How do I update a fleet of Éclair sites?

For each site, replace the app and assets folders, keep data and media, then clear the cache. The [Advanced security and maintenance](https://eclair.academy/en/paths/expert/advanced-security) lesson details the procedure and the backups to plan.