Founder File / Developer Tools
Nikhil Rao
He taught Python to speak fluent web - so the people who can train a neural net can finally ship the front end too.
He taught Python to speak fluent web - so the people who can train a neural net can finally ship the front end too.
Write Python. Get a website. Not a notebook with a chart bolted on - a real web app, front end and back end, login screens and routing and all. That is the trick Nikhil Rao sells, and the strange part is that it works. You write a button in Python and somewhere underneath, Reflex compiles a FastAPI backend and a React frontend you never have to look at.
Rao is the cofounder and CEO of Reflex, the open-source framework that started life as "Pynecone" before growing into something companies now trust with their internal tooling. The pitch is almost suspiciously simple: stay in one language, ship the whole stack. No graduating to JavaScript when the toy gets serious. No rewrite when the prototype becomes the product.
The reach is the part that surprises people. Reflex isn't a weekend hobby kit. By the company's own count it powers internal tools across roughly 30% of the Fortune 500, has crossed a million apps built, and sits above 28,000 stars on GitHub. For a tool that asks you to write zero React, that is a lot of React quietly running in the background.
We're trying to eliminate that graduation risk. You can get started easily, but you're never gonna hit a type of website we can't handle.
The idea didn't arrive in a garage. It arrived in a meeting. At Apple, Rao worked on internal AI applications surrounded by engineers who could do extraordinary things with Python and machine learning - and then stall completely when someone asked for a user interface. Senior people would simply decline the UI work. Not because it was beneath them. Because the jump to JavaScript, React, and the rest of the front-end stack was a second career they hadn't signed up for.
That gap is the whole company. Python had quietly eaten data science, infrastructure, scripting, machine learning - nearly everything. Everything except the one place a user actually clicks. Rao's observation was that the smartest people in the building were locked out of the front end by an accident of tooling, not a lack of talent.
So in 2022 he teamed up with Alek Petuskey - an ML engineer he'd roomed with at Berkeley - and started building the bridge. They shipped the first open-source release in December 2022, posted to Hacker News in early January 2023, and rode the response into Y Combinator's Winter 2023 batch.
Rao met Alek Petuskey at UC Berkeley, where the two were roommates for a couple of years. Petuskey came from ML work at Ancestry.com, with research stops at a UCSF lab and NASA. The company they built together first went by the name Pynecone before rebranding to Reflex.
The rename signaled the ambition: a framework simple enough to learn on reflex, robust enough to never make you switch tools when the project gets serious.
You never write a line of JavaScript. You write Python components, Python state, Python event handlers. Reflex does the translating, then hands you something a browser understands.
The clever bit is that the abstraction doesn't trap you. When you need a custom React component, Reflex lets you wrap it - so the escape hatch is built in rather than bolted on.
We're building a web framework to build web apps in pure Python - front end and back end - without having to learn any new languages or frameworks.TechCrunch, 2023
Python is used in so many areas, but there's really one place that it's not used traditionally. And that's front end development.Talk Python To Me #483
You can get started easily, but you're never gonna hit a type of website we can't handle.TechCrunch, 2023
The early roadmap was modest and concrete: launch a hosting service, smooth out onboarding with templates and components, push the open-source framework toward feature parity with the front-end giants. Useful, unglamorous, the kind of work that makes a tool sticky.
The later ambition is bolder. Reflex has been moving toward an AI app builder - "Reflex Build" - that turns a prompt into a working production app, and toward positioning itself as the platform for mission-critical enterprise software. In December 2025 the company shipped Reflex Build On-Prem, dropping the whole AI builder inside air-gapped enterprise environments where the cloud isn't an option.
Underneath every release is the same wager Rao made at Apple: that the barrier between Python developers and the web was never about ability. It was about tooling. Remove the tooling tax, and a very large group of capable people gets a door that used to be locked.
Most web work is a relay race between specialists. A back-end engineer hands off to a front-end engineer, who hands off to whoever owns deployment. Every handoff is a place for context to leak and momentum to die. Reflex's argument is that for a huge category of software - internal tools, dashboards, data apps, the unglamorous machinery that runs companies - you don't need the relay at all. One person who knows Python can carry the baton the whole way.
That matters because of where Python already lives. It is the default language of data science, machine learning, scripting, and infrastructure. The people who write it are not hobbyists - they are some of the most technical employees in a company. Rao's insight was that this enormous, capable population had been treated as second-class citizens of the web, allowed to compute anything but render nothing. Reflex flips that. The same engineer who builds the model can now build the interface that ships it.
The skeptic's question is obvious: doesn't the abstraction break the moment you need something custom? Rao's answer is the escape hatch. Reflex lets developers wrap arbitrary React components, so the framework never becomes a ceiling. You start in pure Python, and on the rare day you need to drop lower, the door is already there.
A framework asks you to write code. A builder writes it for you. The arc of Reflex from 2023 to 2026 tracks that shift. The open-source library came first - the thing developers install and type into. Then came the hosting layer, the templates, the components, all the connective tissue that turns a library into a product.
By 2025 the company had reached for something more ambitious: Reflex Build, an AI app builder that takes a plain-language prompt and returns a working production app. It is the logical extreme of the original mission. If the goal was always to lower the barrier to building for the web, the lowest possible barrier is describing what you want in a sentence.
The enterprise instinct showed up next. In December 2025, Reflex shipped Build On-Prem - the same AI builder, packaged for air-gapped and on-premises environments where regulated industries keep their most sensitive systems. It is a telling move for a company that started as a Hacker News post: the open-source crowd built the credibility, and the enterprise is where the framework is being asked to prove it can carry mission-critical weight.
The video edition of Talk Python To Me, episode #483, featuring Nikhil Rao. The clearest walkthrough of how the framework thinks.
"From Idea to Working Web App Using Only Python with Reflex." The founder's-eye view of building in the open.