Truell: Cursor post-trains top open-source and closed-source foundation models
Michael Truell · The rise of Cursor: The $300M ARR AI tool that engineers can’t stop using | Michael Truell · May 1, 2025 · at 38:04
Michael Truell is the co-founder and CEO of Cursor (Anysphere). He explains Cursor's strategy for building custom AI models by post-training existing foundational models rather than training from scratch.
0:00 / 0:34exact quote · 34.7s
▶ Watch the full episode on YouTube → 720p mp4 · rendered on demand · StarZero watermark
“Starting from the very best you know pre-trained models that exist out there. Often open source ones, you know, sometimes in collaboration with these big model providers that, that don't share their weights out into the world because the thing we care about less is, you know, the ability to read line by line, you know, the, you know, the matrix of weights that then, you know, go to give you a certain output, and it's, you know, we just care about the ability to kind of, to train these things, to post train them. And so by and large, yes, open source models, you know, sometimes working with the closed source providers too, to tune things.”
quote is from the automated transcript, cleaned for reading: filler sounds and stutters are removed, nothing is rephrased. names can be misheard (the analysis reads context, assessments check outside sources). how →
More from Michael Truell
Truell: Long-term demand for software engineers will increase despite AI
“I think long into the future, yes, there will actually be more demand for engineers.”
Truell: Future coding will use terse pseudocode instead of raw code
“And so a world, you know, kind of after, You know, after code I think it looks like a world where you have a representation of the logic of your software that does look more like English, right? You have kind of written down, you can imagine in doctrine form, …”
Truell: Engineers will rely less on carefulness and more on taste
“I think we will get to a place where you will be able to be less careful as a software engineer, which right now is an incredibly, incredibly important skill. And yeah, we'll move a little bit from carefulness a little bit more towards taste.”
Truell: 'Vibe coding' breaks down when developers cannot understand scaling codebases
“By not understanding the details under the hood right now, you then very quickly get to a place where you're kind of limited. At a certain point where you create something that's big enough that you can't change.”
Truell: AI coding tools must control the full IDE, not just plugins
“The extensibility that existing coding environments have is so, so, so limited. So if you think that the UI is going to change a lot, if you think that the form factor program is going to change a lot, you necessarily need to have control over the entire appli…”
Truell: Cursor's most successful developers use AI conservatively for scoped tasks
“So the customers we've seen have most success with AI, I think are still fairly conservative about some of the ways in which they use this stuff. And so I do think today that the most successful customers really lean on Things like you know, our next edit pred…”