On commercializing nbdev

Why I decided not to commercialize nbdev.

Hamel Husain


May 30, 2023

nbdev is a software development tool based on Jupyter that feels like its from the future.

A few friends have asked me why I decided not to commercialize nbdev, especially after putting lots of work into the project, including leaving my full-time job to work on it. So I thought I would write a short post to explain my reasoning.


nbdev is an innovative software development framework for Python that embraces literate and exploratory programming. I worked on nbdev from 2020-2023 with Jeremy Howard and, later, Wasim Lorgat. I had the privilege and excitement of exploring the boundaries of developer tools and exploratory programming while working with very talented software engineers. In addition to creating a tool many people enjoyed, I enjoyed using nbdev for personal and professional projects.


While conducting product research, I interviewed many developers from different backgrounds to understand their pain points and needs. All developers I talked to struggled with one key challenge: it was difficult, if not impossible, to convince other engineers to use nbdev.

The following are the biggest reasons that prevented adoption:

  • Friction in onboarding engineers. In many companies, there are often existing Python projects, and it can be detrimental to maintain different ways of doing things when a company has already settled upon one way that it has built processes and tools around.
  • Collisions with the rest of the software development stack: it was (and still is) a pain to version control notebooks in a way that’s conducive to collaboration. For practical purposes, you cannot perform code reviews of notebooks on GitHub without purchasing a tool called ReviewNB. So instead of convincing people to use nbdev, you have to convince them to use nbdev and ReviewNB. This makes the barrier to initial adoption considerably high - as procuring software in many organizations is a non-trivial process involving security review, compliance, legal and other stakeholders.

I viewed solving the above problems as potential opportunities for commercializing nbdev.

Shifting Focus

Jeremy, Wasim, and I eventually settled on the idea of “WordPress for developers,” a hosted site allowing people to create and share nbdev projects. We thought this would be an excellent way to get people to try nbdev without installing anything. The idea was to narrow the audience to people interested in hosting projects on a platform that promoted exploration and sharing, similar to Glitch that was as easy to use and pragmatic as Wordpress.

Around the same time we began discussing hosted tools, the machine learning world experienced a tectonic shift due to the explosion of Generative AI, namely Stable Diffusion. fast.ai, the organization that created nbdev, was also changing its focus. fast.ai’s prime directive was to make deep learning accessible to as many people as possible, and generative AI was too important to ignore. Accordingly, Jeremy placed his full attention on a Stable Diffusion course.

This pivot caused some turbulence as we navigated the different priorities of nbdev, generative AI research, and making money. We eventually settled on offering consulting services for everything related to fast.ai in the form of fast.ai partners, which would allow us to bootstrap ourselves financially and embrace the larger mission of fast.ai (including generative AI and research). Eventually, I found the splintered focus across so many areas to be unproductive1 and decided to step away from everything except consulting to regain my footing.

Soon after that, ChatGPT emerged onto the scene and caused further shifts in machine learning that were orders of magnitude larger than their text-to-image predecessors. Pretty soon, all of my clients were interested in language models, and I found myself working exclusively on operationalizing them (a skill that I have cultivated by working in machine learning for 20+ years). Additionally, LLMs profoundly changed the nature of software development, especially the kind of software development that nbdev was designed to support2. These factors and those discussed earlier suggested it was a good time to step away from nbdev and focus on other things.

What I learned

I learned some important lessons during this process:

  1. Just because you love a project and find it useful, that doesn’t necessarily imply that it’s ripe for commercialization. I always struggled to gain conviction that there was a good business model for nbdev.3 Instead, I pursued this path because I was drawn to the idea of starting a business with people I really liked. Ultimately, I learned that at least one person needs strong conviction in addition to being excited about the people you are working with - not just one or the other.4 I also learned that it’s important to be honest with yourself about your (and your team’s) level of conviction and not try to force something that isn’t there.
  2. Listen to your instincts. I ignored my instincts on multiple occasions throughout this journey. As I’ve grown older, I’ve learned to make this mistake much less often, but I could have done better here.
  3. Don’t be afraid to pivot. I think we avoided unnecessary churn by steering clear of a situation that wasn’t promising. I’m much more excited about the work I’m doing now.5
  4. Own your own brand. My professional brand became increasingly tied to fast.ai and my friend Jeremy Howard. I’m grateful for the growth I’ve experienced under this mentorship – but I believe it is important to build your own distinct brand and identity. I discovered it can be challenging to build your own brand when you are working on someone else’s project6, and is something I struggled with. I’m looking forward to working on this more.

Future Directions

I suspect that I’m not completely finished with nbdev. I may revisit the project or related ideas when the time is right. I’m excited by the work Posit is doing in the areas of literate and exploratory programming, which include many of the ideas explored in nbdev. Wasim has even joined the team at Posit, so I’m excited to see what they come up with.7

Regarding what I’m working on next – I’ll have to save my thoughts on that for another post 😊.


  1. I burned out several times during this process, but I didn’t realize why at the time. Not surprisingly, trying to focus on too many things at once was the root cause.↩︎

  2. See this demo for ideas on how coding with LLMs might look like, especially with notebooks.↩︎

  3. The problem with the hosted solution is that this is not something I would want to use. I can’t picture myself trying to host code on something other than GitHub/GitLab.↩︎

  4. Without shared conviction, there is no glue holding everyone together and people can drift apart.↩︎

  5. I’ll share more about this in a future post.↩︎

  6. I don’t believe this is always the case, but it can be true depending on the dynamics of the group.↩︎

  7. We previously partnered with Posit and JJ Allaire and built nbdev on top of Quarto. I’m currently advising Posit on their product and strategy. They have additional projects on their roadmap that I cannot disclose now.↩︎