Today we’re thrilled to announce that Lux Capital is leading the $5 million seed round of Reflex, joined by friends at Abstract Ventures, Box Group, Y Combinator, Picus Capital and Outset Capital as well as notable angel investors including Qasar Younis, CEO of Applied Intuition, Jack Altman, CEO of Lattice, and Paul Copplestone, CEO of Supabase.

Web apps are everywhere — powering most interactions on the Internet, internal enterprise tools and the latest AI services. Despite their ubiquity, they aren’t straightforward to build – most sophisticated web apps require both frontend and backend expertise like mastering JavaScript and React. The rise of low-code and no-code frameworks have made web development more accessible, but also enforce new limitations and graduation risks.

Simultaneously, we’ve seen a trend toward developers becoming more specialized as they learn specific coding languages according to use case — an engineer with a strong grasp of Python who knows how to train large language models in PyTorch, for example, may have little to no experience building a web app in JavaScript.

Enter Reflex (fka Pynecone): a platform to build web apps in pure Python, empowering developers to build their whole web app seamlessly (both frontend and backend) providing the flexibility of a traditional web framework with the simplicity of one language and one framework for the full stack. Reflex allows Python developers to become full-stack engineers without learning a new toolchain like JavaScript plus React and Next.js.

Reflex is easy to use - developers can deploy it with a single Python command. It’s also intuitive to learn and highly flexible with 61 modular, pre-made UI components (e.g. embeddable texts, buttons, graphs). Reflex integrates seamlessly with existing databases and libraries and is fully customizable, scaling to support a simple web app to a complex multi-page internal tooling system.

Since Reflex’s launch in December 2022 as an open-source project, its community has grown to 5,000 monthly developers making 15,000 Reflex apps, with 61 contributors to their GitHub project, and over 1,400 members in their Discord. The community includes a broad range of skill levels and use cases, from software engineers building internal apps at Fortune 500 companies to startups building their main customer-facing apps across a wide range of industries from biology to manufacturing and quant trading.  

A gallery of Reflex apps is viewable on the website including LLM applications like their DALL-E app and internal infrastructure like authentication with Firebase. Reflex was also previously featured on HackerNews and on GPT-4’s developer livestream. What Vercel did for the Next.js and React communities, we believe Reflex will do for the Python community.

Reflex co-founders Nikhil Rao and Alek Petuskey met at Berkeley – Nikhil was an early engineer at Drive.ai then Apple where he built internal AI applications while Alek was an ML engineer at Ancestry.com and researcher at both the Bender Lab at UCSF and NASA. We were struck by their combination of technical rigor and strong sense of hustle, grit and ambition. Characteristic of Lux founders, they are solving a meaningful challenge they faced themselves, answering the question “what sucks?” in web development and going a step beyond to reinvent the application development experience.

We’ve been especially impressed by their execution velocity: in a matter of months they were able to not only launch an incredible product but also grow an impressive community, hire top engineers and build out a sophisticated long-term product roadmap. Stay tuned for their hosting service beta to quickly deploy, scale, and share apps.

Most excitingly, Reflex is hiring! Sign up for the product today on their website and join their Discord to learn more.

~ Grace Isford and Brandon Reeves