The First Mechanistic Interpretability Frontier Lab — Myra Deng & Mark Bissell of Goodfire AI

**Shawn Wang** (0:06)
So, welcome to the Latent Space Podcast. We're back in the studio with our special MechInterp co-host, Vibhu. Welcome.

**Vibhu** (0:12)
Mochi, Mochi's special co-host.

**Shawn Wang** (0:14)
And Mochi, the mechanistic interpretability doggo. We have with us Mark and Myra from Goodfire. Welcome.

**Mark Bissell** (0:21)
Thanks for having us on.

**Shawn Wang** (0:23)
Maybe we can sort of introduce Goodfire and then introduce you guys. How do you introduce Goodfire today?

**Myra Deng** (0:29)
Yeah, it's a great question. So, Goodfire, we like to say, is an AI research lab that focuses on using interpretability to understand, learn from, and design AI models. And we really believe that interpretability will unlock the new generation, next frontier of safe and powerful AI models. That's our description right now. And I'm excited to dive more into the work we're doing to make that happen.

**Shawn Wang** (0:55)
Yeah. And there's always like the official description. Is there like an unofficial one that sort of resonates more with a different audience?

**Mark Bissell** (1:02)
Well, being an AI research lab that's focused on interpretability, there's obviously a lot of people have a lot that they think about when they think of interpretability. And I think we have a pretty broad definition of what that means and the types of places that can be applied. And in particular, applying it in production scenarios, in high stakes industries, and really taking it sort of from the research world into the real world, which, you know, it's a new field so that hasn't been done all that much. And we're excited about actually seeing that sort of put into practice.

**Shawn Wang** (1:37)
Yeah. I would say it wasn't too long ago that Anthopic was still putting out toy models, a superposition, and that kind of stuff. And I wouldn't have pegged it to be this far along. When you and I talked at NeurIPS, you were talking a little bit about your production use cases and your customers. And then, not to bury the lead, today we're also announcing the fundraise. Your Series B $150 million at a 125B valuation. Congrats, you're a Unicorn.

**Mark Bissell** (2:02)
Thank you. Things move fast. We were talking to you in December and already some big updates since then.

**Shawn Wang** (2:08)
Let's dive into a bit of your backgrounds as well. Mark, you were at Palantir, working on health stuff, which is really interesting because Goodfire has some interesting health use cases. I don't know how related they are in practice.

**Mark Bissell** (2:22)
Yeah, not super related, but it was a helpful context to know what it's like just to work with health systems in that domain.

**Shawn Wang** (2:32)
Myra, you were at Two Sigma, which I was also at Two Sigma back in the day.

**Myra Deng** (2:37)
Wow, nice. Did we overlap at all?

**Shawn Wang** (2:39)
No. This is when I was briefly a software engineer before I became a developer relations person, and now you're head of product. What are your respective roles to introduce people to what all gets done in Goodfire?

**Mark Bissell** (2:51)
Yeah. Prior to Goodfire, I was at Palantir for about three years as a forward deployed engineer.
Now a hot term wasn't always that way, and as a technical lead on the healthcare team. And at Goodfire, I'm a member of the technical staff, and honestly, that I think is about as specific as I could describe myself because I've worked on a range of things, and it's a fun time to be at a team that's still reasonably small. I think when I joined one of the first like 10 employees, now we're above 40, but still it looks like there's always a mix of research and engineering and product and all of the above that needs to get done. And I think everyone across the team is pretty switch hitter in the roles they do. So I think you've seen some of the stuff that I worked on related to image models, which was sort of like a research demo. More recently, I've been working on our scientific discovery team with some of our life sciences partners, but then also building out our core platform from more of flexing some of the MLE and developer skills as well.

**Shawn Wang** (3:53)
Very generalist. And you also had a founding engineer type role.

**Myra Deng** (3:58)
Yeah, so I also started as, I still am, a member of technical staff, did a wide range of things from the very beginning, including finding our office space and all of these nitty gritty things.

**Shawn Wang** (4:10)
We both visited when you had that open house thing. It was really nice.