Lesli 5.1 — The Official Release

Today I am releasing Lesli 5.1 as the first official stable release of the framework.

This is not just a version release. It is the result of a long process of rebuilding, cleaning, removing old proprietary code, and shaping Lesli into something I finally feel proud to share publicly.

For me, this release means something simple: Lesli is finally ready to begin its real life as an open source framework.

What is Lesli?

Lesli is a Ruby on Rails framework for building business software.

It is designed for systems that need more structure than a typical Rails app usually has after a few years of growth. Things like internal platforms, SaaS products, administration tools, support systems, CRM-style modules, audit features, and other business capabilities that usually grow over time and become harder to maintain.

At its core, Lesli is built around a modular approach using Rails engines, shared conventions, and reusable modules.

The goal is not to be clever. The goal is to help developers build software that can grow without becoming a mess.

Lesli is not an admin panel. It is not a starter kit. And it is not a collection of disconnected gems.

It is my attempt to build a serious foundation for long-term business software in Rails.

Why I Have Worked on Lesli for So Long

Because I care a lot about software that stays useful over time — and because I like software design and architecture :D

I have worked on business systems for many years, and one thing becomes obvious very quickly: most software does not fail because the first version was impossible to build. It fails because, after some time, it becomes too hard to change, too hard to extend, and too expensive to maintain.

That problem stayed with me for a long time.

I did not want Lesli to be just another framework announcement, or another project that looks good from the outside but was never shaped by real use. I wanted it to come from real work, real mistakes, real migrations, real clients, and real systems.

That is why this has taken so long — two years of hard work to make this release possible.

A big part of that work was technical. During this stage, I migrated the frontend from a SPA built with Vue to a Hotwire-based approach that fits much better with the kind of Rails framework I want Lesli to be.

That migration was not small. It meant rethinking how the framework should feel for developers, simplifying parts of the architecture, and aligning the frontend with the Rails-first philosophy that now defines Lesli much more clearly.

At the same time, since 2024, I have also been doing the work of removing proprietary code and separating everything that should not belong in an open source release. That process was not glamorous. It was slow, sometimes repetitive, and emotionally heavy, because it meant revisiting many years of previous work and deciding what Lesli should become from this point on.

This release matters to me because it closes that chapter.

A Short History of Lesli

Lesli did not start as an open source Rails framework.

The idea goes back to 2014. At that time, Lesli was private software built with PHP, created to provide useful and affordable tools for small businesses in Guatemala. The goal was practical from the beginning: help companies that needed software to manage their operations, but did not have access to expensive enterprise systems or complex infrastructure.

The earliest version was built for very simple environments, sometimes with nothing more than a website running on shared hosting with PHP and MySQL. Lesli started there, with limited conditions and very real needs.

Over time, the software grew. It became a more complete standalone system, and later I rebuilt major parts of it with different technologies while trying to make it more modular, more flexible, and more adaptable to custom requirements.

Then in 2019, I was introduced to Ruby on Rails. That changed everything.

I fell in love with Rails very quickly. I saw in it the clarity, productivity, and balance that I had been looking for. So I made a decision that, at the time, felt a little crazy: I dropped a lot of previous work and started migrating the core of Lesli to Rails.

In 2020, I started working with investors with the idea of using Lesli to build internal software systems across multiple companies — administration, HR, marketing, sales, and other business processes.

That stage did not go as I expected. But it was still important, because during that time I was able to shape the first real version of Lesli as a framework instead of only a product.

Then in 2024, after stepping away from that stage, I made a much more personal decision: I decided to continue building Lesli on my own and turn it into open source software.

Since then, I have been working on removing proprietary code, cleaning boundaries, restructuring the framework, and preparing a version that I could release honestly and confidently.

So when I say that Lesli 5.1 matters to me, it is because this release is not the beginning of an idea. It is the result of more than a decade of evolution.

Why Give Lesli a Chance?

Because Lesli comes from a very real problem.

It was not created to follow a trend. It was not created to impress people with abstract architecture. It was created because business software keeps growing, and when it grows without structure, developers pay the price later.

I think Lesli is worth exploring if you care about things like:

Lesli is especially for developers who like Rails, but want a stronger structure for bigger systems.

It keeps the spirit of Rails, but pushes the architecture toward modularity, isolation, and long-term maintainability.

And beyond the technical part, I think there is another reason to give it a chance: this framework was built with patience. It was shaped over many years, not over a weekend.

What This Release Means

Lesli 5.1 is the first official stable release.

For the project, this means the framework has reached the point where I feel comfortable inviting developers to explore it, test it, build with it, and follow its growth.

For me personally, this release means the end of two very difficult years of removing proprietary code, migrating the frontend from Vue SPA architecture to Hotwire, and turning the framework into something clean and coherent enough to release publicly.

So this version is important because it marks a transition.

From private history to public framework. From unfinished cleanup to a stable base. From something I carried for many years to something I can finally share properly.

What Lesli Includes

Lesli already includes the base structure and a growing ecosystem of modules for common business software needs.

That includes things such as:

The framework is meant to grow as an ecosystem, where modules can stay organized and isolated instead of turning the whole application into a single block of mixed responsibilities.

How to Try Lesli

If you want to explore Lesli quickly, there are a few easy ways to do it.

Live demo

You can open the online demo and see the framework running directly in the browser: https://demo.lesli.dev.

Local demo with Rails template

You can also generate a demo app locally:

rails new LesliDemo -m https://www.lesli.dev/rails/template-dev.rb

Local demo with Docker

Or run a local demo using Docker:

git clone https://github.com/LesliTech/lesli-docker-demo.git
cd lesli-docker-demo
docker compose up --build

Thank you to everyone who takes the time to read about it, test it, question it, or support it. There is still a lot to improve, a lot to document, and a lot to build.

I have been carrying this project for a long time. It means a lot to finally say this clearly:

Lesli 5.1 is officially released.


Explore Lesli