Performance & Rendering Engineer - Penpot by Kaleidos

About Kaleidos and Penpot

Kaleidos is the company behind Penpot, the first open source design platform built for design and code teams to work together. We're a horizontal organization, with no traditional hierarchy, and our values are grounded in free software principles, along with honesty, feminism, work-life balance, transparency, generosity, and joy in what we do. At Kaleidos we have a real commitment to diversity in all its forms. Our team is made up of more than 50% women, and we'd love to find new teammates who share our values, who we can keep learning from and keep building Penpot with.Kaleidos is the company behind Penpot, the first open source design platform built for design and code teams to work together. We're a horizontal organization, with no traditional hierarchy, and our values are grounded in free software principles, along with honesty, feminism, work-life balance, transparency, generosity, and joy in what we do. At Kaleidos we have a real commitment to diversity in all its forms. Our team is made up of more than 50% women, and we'd love to find new teammates who share our values, who we can keep learning from and keep building Penpot with.

What will your work be like?

At Penpot we build the design tool that brings together people who design and people who code, within a free, collaborative software environment. We're constantly adding new features that the community and our users ask for, and our challenge is to make all of them as stable and efficient as possible.

You'll be part of a small team working in Rust on Penpot's rendering engine (built with WASM, Rust, and Skia), on the text editor, and on ongoing performance improvements. Your work will be focused on fixing bugs, improving performance, and building new features for that engine. Performance is the main focus: help us make Penpot run smoothly in the browser, with response times as fast as possible.

You'll also have some points of contact with the frontend, mainly when it comes to passing data between Clojure and the engine. That's why you need to feel comfortable with web programming and with the fundamentals of functional programming.

We're looking for someone with senior, solid, consolidated experience, to work within a horizontal team with no manager figure: autonomy and shared decision-making are part of the role.

At Penpot we build the design tool that brings together people who design and people who code, within a free, collaborative software environment. We're constantly adding new features that the community and our users ask for, and our challenge is to make all of them as stable and efficient as possible.

You'll be part of a small team working in Rust on Penpot's rendering engine (built with WASM, Rust, and Skia), on the text editor, and on ongoing performance improvements. Your work will be focused on fixing bugs, improving performance, and building new features for that engine. Performance is the main focus: help us make Penpot run smoothly in the browser, with response times as fast as possible.

You'll also have some points of contact with the frontend, mainly when it comes to passing data between Clojure and the engine. That's why you need to feel comfortable with web programming and with the fundamentals of functional programming.

We're looking for someone with senior, solid, consolidated experience, to work within a horizontal team with no manager figure: autonomy and shared decision-making are part of the role.

What do we need

We believe that education can be acquired in many ways, not just through a degree. That's why we don't require specific formal education, but we do expect you to have senior experience in the following areas:

• Rendering engines. Here you'll find WASM, Rust, and Skia (so it's great if you have experience building game engines, graphics libraries, rasterization, GPU pipelines...). You don't need to be an expert in these specific technologies or in graphics APIs, but you should have definetely worked with them before, and feel comfortable getting better at them.
• Hands-on experience with frontend technologies, with a good command of JavaScript, browser APIs, HTML, and CSS.
• Regular use of LLMs (Claude, Cursor, ChatGPT, OpenCode...) as part of your way of working, among other things to make it easier for you to interact with and integrate into Penpot's Clojure core. We've brought AI into our development processes and we have open discussions and workstreams focused on finding the best way to use AI, taking into account many different aspects (technological possibilities, digital sovereignty / open source, ethics...).
• Comfortable working in Linux environments.
• Languages: high level of spoken and written English and Spanish. We need you to be able to read and write technical documentation and speak functionally in English, since it's the first language for some kaleiders. It's also necessary that you know Spanish (spoken and written), since many team meetings are …