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Sam Lessin
General Partner, Slow Ventures

Building the AI-Assistant that Sam Lessin Couldn't | Will Ruben (Workmate Labs) and Sam Lessin

📅 Jun 26, 2025 Slow Ventures 19 MIN 436 VIEWS 34 SEGMENTS · 2 SPEAKERS
The “AI for X” pitch is getting tiring… The real breakthrough will happen when it actually works. Get an inside look at why building AI assistants is so challenging — from people who are building them or have tried to. Sam Lessin, who previously built Fin — an assistant service pre-AI — and Will Ruben, founder of Workmate Labs, compare notes on the state of AI assistants now versus then. Chapters: 00:00 Intro & Bullshitting About Startups Setting the stage: Facebook era, why Workmate, and what’s broken with assistants. 01:18 Why Now? The AI Timing Play “Startups are all about timing… In a yea...

Questions asked in this interview

12
  1. 0:02Like what got you really excited to do this as opposed to all the things you could do?
  2. 2:52And I guess the question I have for you on that is like, what gives you that confidence that like now is the moment that it works?
  3. 4:31How do you build that muscle?
  4. 5:55How do you have confidence that like AI doesn't get so good that like there's no company to build, right?
  5. 7:03When you think about those like compound things, how do you think about creating like the right level of interface or handoff for initially?
  6. 9:39I'm kind of curious, like, are they a competitor?
  7. 10:18So, like, what are some of the problems with Calendly today?
  8. 10:28But so, what are some of the problems with Calendly today?
  9. 11:15The other thing that... How do you do that?
  10. 12:27You hire people to shift responsibility, right?
  11. 15:22In terms of like how you design and build it, right?
  12. 16:52What's been the most surprising thing so far in building the company?
Sam Lessin 0:00 ↗
Will, Sam is Ruben. Good to see you, man.
Will Gabrick 0:02 ↗
Sam, great to see you. Thanks for having me. I appreciate you joining to talk about startups and things like that. So, look, I mean, you and I know each other from the Facebook era. You've now gone off and started your company, which I'm excited that you took the leap. You want to start by giving everyone kind of a quick overview of like what it is you're working on and kind of why I think importantly when you think about like why this one? Like what got you really excited to do this as opposed to all the things you could do?
Sam Lessin 0:27 ↗
Yeah. So, I'm working on Workmate. We're building an AI-powered executive assistant that helps you schedule your meetings, manage your calendar, prioritize your preferences. You can stop spending time scheduling and just hire a workmate. What got me excited about this was the very personal experience that I had. I know we worked together for a long time. You had an assistant named Kelly. I had several other assistants. They were lifesavers when it was working really well. But when I lost access or someone left or I switched jobs, my life would get significantly worse sometimes and my work product would get significantly worse. At the end of the day though, I felt like it was something that could be democratized with AI and with technology, kind of the same way that a private driver 20 years ago was something for the few and the rich, and now we all have access to some version of it at our fingertips all over the world. I think executive assistance will be the same. People will be better at work and have more balance in their life with AI by their side, and that will happen for them without having to hire a person that sits next to them 24/7.
Will Gabrick 1:41 ↗
So it makes sense. I mean, obviously, you know, a generation ago now I started something called Finn and we ended up doing a lot of scheduling tasks. There was a bunch of people who have tried scheduling as like an assistant service. There's also been a bunch of people who have tried just like Calendly has been very successful. Like, how do you think about like what's come before in the market for these things and kind of the nuances of, you know, yes, it's a nice vision, taking vision into like, all right, it's time to go.
Sam Lessin 2:04 ↗
Startups are all about timing and I think this is the time for this idea. I think people have tried it in the past and frankly it just didn't work. Like there was Clara and x.ai and, you know, Finn to a lesser extent because it was more for your personal life than your work life. You know, I think all of those, the technology just wasn't there to fully automate it and people have a pretty high bar for this stuff, especially if they're putting it in the middle of their important work relationships. And so I think why now, because now it will actually work and it will work in a way that feels human, feels like you're working with a human and not like you're interacting with a bot or that you're interacting with an app.
Will Gabrick 2:52 ↗
Fair enough. And I guess the question I have for you on that is like, what gives you that confidence that like now is the moment that it works? Like what, because you clearly could have done a bunch of things and clearly did your homework on this. I'm kind of curious, you know, what you think the sea change is beyond just quote-unquote AI.
Sam Lessin 3:06 ↗
I think there's two things. One is that the technology actually will be there, and that we've already seen in the year and change that we've been working on this that the technology has evolved substantially, where like the reasoning models are making it much more possible to create something that's more human-like and has the flexibility to actually accomplish a wide range of scheduling tasks and other tasks in a flexible way rather than in a pre-prescribed workflow way. And so I think the whole bucket is that like the reasoning models have changed the game even in the last six to 12 months in terms of what's possible. And a year ago I saw that accelerating but I couldn't necessarily say that it was going to get there, nor could anyone, but like the pace of progress over the last year makes me even more confident that over the next year it will get there. The second thing is people's acceptability of AI in their life and in between their important relationships has also changed dramatically. Like I think the appetite for trying new AI tools and for being cool if you're trying AI tools rather than being worried to show other people that you're trying AI tools has changed dramatically. There's a huge appetite to try things like this and everyone believes that this is an inevitability, which makes it more socially acceptable.
Will Gabrick 4:31 ↗
So I guess I get the social part. I want to dive more into the technology part. So like as an entrepreneur and founder, when you think about playing these curves where you're like, it's not there yet but I think it gets there, how do you do that? How do you get confidence and like where are you taking kind of like a leap of faith? How do you build that muscle?
Sam Lessin 4:46 ↗
I think the honest answer is that you have to take a leap of faith. Honestly, we can talk all day and, you know, in the boardroom pitching VCs, you can create some good talking points, but at the end of the day, it's a leap of faith. You get excited about a technology and you think you'll be able to do something cool and new with it. And for me, the emotional reaction was when I felt like I could create something cool and new that wasn't going to be possible, or that there was a chance and I had to try. Yeah. I contrast that with maybe like, you know, five years ago when I thought about doing something and I never got excited about what cool and new could be created because I think there was a period of time when we had done mobile and there wasn't a new technology that was going to change the world, or had a chance of changing the world, that I got excited to take that leap of faith on. And, you know, I don't totally know whether it's going to fully work and, you know, maybe we end up building something that looks more like an app-human hybrid. But we're all in trying to make it feel fully human. And I would rather fail on the big vision than succeed on something small.
Will Gabrick 5:55 ↗
How do you have confidence that like AI doesn't get so good that like there's no company to build, right? Like that you come out the other side where it's like too easy to schedule.
Sam Lessin 6:06 ↗
Yeah. Again, you have to believe that there is value in going really deep on a certain task and that the nuances of that task are important. And I think there are two things that give me the confidence. One is that people have a very high bar. So a medium degree of quality is not going to be enough for most people. This is something that has to be 95% right, human level. And two, that it's actually been hard so far. That there's a lot of nuance. Yeah. And I think three is that I think the opportunity is bigger than scheduling. Like this thing that we have in our hand, it's a phone and it wouldn't have been a phone without making phone calls. The same way that an assistant wouldn't be an assistant without helping you schedule. But I do think that the AI executive assistant will be able to do different things over time from the human executive assistant. Scheduling is the bridge.
Will Gabrick 7:03 ↗
Yeah, I buy that. I mean, that was I think one of the things we experienced with Finn is like scheduling, and when we kind of were working on similar things, again more on the personal side but some business, was that scheduling was an interesting one because it was kind of the tip of the spear. But one of the biggest problems with it is that no scheduling task is actually a scheduling task, right? Like if you think about it, it's not purely scheduling. It's scheduling plus get a dinner reservation. It's scheduling plus book a meeting room. It's scheduling plus, you know, whatever. When you think about those like compound things, how do you think about creating like the right level of interface or handoff for initially? I assume long term you do want to do all those things, but like initially you're like, that is a complete single product in an AI context.
Sam Lessin 7:45 ↗
Yeah. I think one of the reasons why we're starting with work rather than personal is I think the tail of compound scheduling tasks and the other things you have to do is way, way longer on the personal side than in the work context. Like for people who are in back-to-back meetings all day long, who are very externally facing in their role, who are interfacing about scheduling over email, the same way we coordinated this thing, many tasks are scheduling tasks only. In this virtual world, it's even more the case where most of your meetings, a high percentage of your meetings, are scheduling with a video link. Now, there's a lot of nuance involved in that too. Maybe you're scheduling with multiple members of your own team and multiple members on another team and your assistant needs to keep track, speak on behalf of everybody, or maybe you want to manage your time in a certain way and you don't want to give all your availability, or you're going to be traveling and you're in a different time zone. So there's a lot of nuance in scheduling, which to the other point gives me the confidence. I've been surprised at like, I thought we were going to have to make a ton of restaurant reservations and someone did ask us to book a car and we can't currently do that, but that's been the minority of things. And people are already fragmenting their scheduling as well. You can use Calendly for some things, you can do it yourself for other things. Even if you have a human executive assistant, it's not always appropriate to loop them in, or you may not want to always loop them in unless the other person does it first. We just have to create a product that sets the right expectations and then get better and better at those things over time. I will add though that I don't think a lot of these things are going to be hard and they're certainly a lot easier than they were five, ten years ago when you were trying. Like booking a dinner is going to be an MCP tool call in one year.
Will Gabrick 9:39 ↗
We'll see. But yes, I get the hope for sure. I get the hope. How do you think about Calendly? I'm kind of curious, like, are they a competitor? Like to me, the thing I'd be worried about is that they've shaved off so much of the kind of rote stuff. Like, you know, you think about like things that are truly like plug-the-hole sales type stuff, is like they've shaved off so much that kind of what's left is this more nuanced, harder task. In a lot of ways, there's a tough market to enter in.
Sam Lessin 10:06 ↗
Yeah. So I think we're good at the more nuance. That's why people want us over Calendly, and we're already starting to see that. That's why people want to hire a human over it. That's why you're not using Calendly.
Will Gabrick 10:18 ↗
So, like, what are some of the problems with Calendly today? I'm famous for hating on Calendly.
Sam Lessin 10:23 ↗
Yeah, I know. Just sign up for a link in the bottom of your email and you'll call on your own time.

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APA

Lessin, S. (2025, June 26). Building the AI-Assistant that Sam Lessin Couldn't | Will Ruben (Workmate Labs) and Sam Lessin [Interview transcript]. Slow Ventures. CEOInterviews.AI. https://ceointerviews.ai/interview/3030474/

MLA

Sam Lessin. "Building the AI-Assistant that Sam Lessin Couldn't | Will Ruben (Workmate Labs) and Sam Lessin." Slow Ventures, 26 Jun. 2025. Transcript, CEOInterviews.AI, https://ceointerviews.ai/interview/3030474/.

BibTeX
@misc{lessin2025_3030474,
  author       = {Sam Lessin},
  title        = {Building the AI-Assistant that Sam Lessin Couldn't | Will Ruben (Workmate Labs) and Sam Lessin},
  howpublished = {Interview transcript, Slow Ventures. CEOInterviews.AI},
  year         = {2025},
  month        = {jun},
  url          = {https://ceointerviews.ai/interview/3030474/},
  note         = {Speaker-attributed transcript with timestamps}
}