Mercado Libre: 18k engineers, 30k deploys a day, & their own fleet of planes | Sebastian Barrios

Steve Jobs called you.

One day I'm walking in the street and I get a phone and a blocked number. I was super young by the way at the time I think I was like 16. I pick up and I say, well, hi, it's Vashin. This is Steve from Apple. I need to talk to you about your app. We're not going to be able to have it on the App Store. I actually pushed back a little bit until I read all the rules of the App Store.

He told me check again because we just added a new rule.

At 19, you build an app that became the number one app in 19 countries. It absolutely exploded. I actually got contacted by a lot of different companies like multinationals, Governments saying like, well, you have the number one app. We want you to build an app for us.

You oversee something like 18,000 developers.

We do around 30,000 deployments per day. We deliver over 5 million packages per day.

You're really big on not creating a big distinction between engineering and product.

It's hard to separate where engineering stops and product begins, and we don't feel like just having a title should determine who is the owner.

Is there anything else that might be helpful for It's either about how you operate as a human, morning routine.

We were raised in a very intensely independent way. My mother mainly, the analogy that she used is that she wanted to train us like spies. She would drop us in the middle of the city, Mexico City. It would be like, you have to get back home. You have to like know public transit or ask someone for help and basically it solves problems. Just go and get things done.

Today my guest is Sebastian Barrios. Cebas, as most people know him, is currently Senior Vice President of Engineering at Roblox. He was also a long time head of product and engineering at Mercado Libre. Mercado Libre might be the biggest and most interesting company that you have never heard of, and Sebas might also be the most interesting product leader that you've never heard of. Mercado Libre is currently the most valuable company in Latin America valued at over $100 billion, which also makes them one of the 150 most valuable companies on the planet. They also have one of the largest engineering teams on the planet with over 18,000 engineers operating in 18 countries. They deploy an unprecedented 30,000 times a day. The company owns their own trucks and planes. They deliver over 5 million packages a day. At one point, eBay tried to acquire them. They ended up acquiring PayPal instead. Now they are larger than both eBay and PayPal combined. Also, just wait till you hear the stories about Sebas' early life, including how his mom trained him like a spy, why he only drinks water, no coffee or tea or juice, why he doesn't listen to music, and also why Steve Jobs personally called him when he was 17 years old, telling him that they are booting his app from the App Store and forever changing the App Store policies as a result. A huge thank you to Christopher Lazarus, Oscar Mullen, and Farhan Thawer for suggesting topics for this conversation. If you enjoyed this podcast, don't forget to subscribe and follow it in your favorite podcasting app or YouTube. Also, if you become an annual subscriber of my newsletter, you get a year free. of Bolt, Linear, Superhuman, Notion, Perplexity, Granola, and more. Check it out at Lenny's Newsletter.com and click bundle. With that, I bring you Sebastian Barrios. This episode is brought to you by Merge. Product leaders, yes, like you, cringe when they hear the word integration. They're not fun for you to scope, build, launch, or maintain, and integrations probably aren't what led you to product work in the first place. Lucky for you, the folks at Merge are obsessed with integrations. Their single API helps SaaS companies launch over 200 product integrations in weeks, not quarters. Think of Merge like Plaid, but for everything B2B SaaS. Organizations like Ramp, Jirada, and Electric use Merge to access their customers' accounting data to reconcile bill payments, file storage data to create searchable databases in their product, or HRIS data to auto provision and de-provision access for their customers' employees. And yes, if you need AI-ready data for your SaaS product, then Merge is the fastest way to get it. So, want to solve your organization's integration dilemma once and for all? Book and attend a meeting at merge.dev/lenny and receive a $50 Amazon gift card. That's merge.dev/lenny. This episode is brought to you by Vanta. When it comes to ensuring your company has top-notch security practices, things get complicated fast. Now, you can assess risk, secure the trust of your customers, and automate compliance for SOC 2, ISO 27001, HIPAA, and more with a single platform, Vanta. Vanta's market-leading trust management platform helps you continuously monitor compliance alongside reporting and tracking risk. Plus, you can save hours by completing security questionnaires with Vanta AI. Join thousands of global companies that use Vanta to automate evidence collection, unify risk management, and streamline security reviews. Get $1,000 off Vanta when you go to vanta.com/lenny. That's V-A-N-T-A.com/lenny. Sebas, thank you so much for being here and welcome to the podcast.

Super happy to be here. Thank you for hosting me.

This is the first time that you're doing a major, let's call it major podcast.

I think you can call it major podcast. You can be proud of what you've done.

I appreciate that. So let me just start with a stat that I think is going to blow a lot of people's minds. You oversee something like 18,000 developers. Is that right? Is that the right number?

That is the right number. 18,000 and climbing. I just specify that they don't report all directly to me. We can talk about how the company is structured, but yes, I lead the technology team that basically powers all of what they do.

I think essentially you guys are in the top 10 of most engineers at a company. You're above Salesforce and TikTok, Nvidia, Adobe, Uber, OpenAI.

That's right. I think you have to go into big tech or huge banks to to get a larger number.

Okay. So a lot of people listening to this have not heard of Mercado Libre. A lot of listeners are in the US, other parts of the country outside of Latin America. Give us just like a brief explanation of what does Mercado Libre do, and then give us a few more stats that will blow people's minds to the scale of this business at this point.

Happy to, happy to. So you can think of us as a completely vertically integrated e-commerce marketplace. That means buying and selling any product you can think of. And the vertically integrated part means we have our own distribution network, we have our own airplanes, we have our own trucks, we have to do all the technology and coordination behind that. But even, or in addition to that, we also have a very large FinTech operation. The two sides of the business are actually almost the same size. So we also offer accounts, we offer credit cards, we offer loans, all of that. integrated with each other into what we call an ecosystem.

Okay, and I saw a stat that you guys plan to have over 100,000 employees by the end of this year.

That's right. There's a lot of operations that need to happen for all those packages to be delivered. You asked about some fund statistics specifically with deliveries. We deliver over 5 million packages per day or items. So you visit most of Latin America. We have some very cool visualizations where if you track the routes of our trucks and delivery vans and whatnot, you sort of like paint a picture of Latin America, which is pretty fun. We obviously operate in major cities, but we have very, very large capillarity and reach all the different corners of Latin America.

Okay, a couple more stats that you didn't mention. You guys are valued over $100 billion.

It's a large company. We don't focus on the stock price that much. But yes, 100 billion, even more so now, depends on how the market's feeling and what the global news are. But yes, one of the top valued companies on the planet, we have around 100 million users, customers, sellers, people interacting in the platform. And as you mentioned, one of the larger engineering and product building teams on the planet.

Hopefully people now get the sense of like, holy shit, there's a lot to learn here. There's kind of two buckets to the way I want to approach this conversation. One is just really unique, interesting ways you all operate and how you scale a business like this, how you build product. The other is just you as a human are really interesting. And there's a lot of stories I've heard that I want to talk about, but I'm going to save that for next. Let's start with how you all operate. So I talked to a lot of people that work with you, that work at Mercado Libre. One of the themes that came up again and again is you're really big on not creating a big distinction between engineering and product. It's essentially one team for you guys. Talk about just how that works specifically, just like what does that mean and why that's so important to you.

For me and for Mercado Libre, it's hard to separate where sort of like engineering stops and product begins. We do have a small product organization. There are people in Medical Leve that have the product manager title, but the ratio is much smaller than any other tech company that you would think of. And the way we think about it is like that we're not going to determine who's going to own the product just based on the title. It's going to be based on who's the best for that role. And then it turns out that for us and the majority of the cases, it's the engineering leaders, it's the tech leads, it's the the people that can understand what's technically possible and they're also good about, okay, what are the business needs? What are the user needs? What are the users doing? How am I going to measure that? No, and combine that into a single role.

So to make this even clear, you have 18,000-ish developers. How many people have the PM title?

So I think it's less than 1,000. I think that would make 5%. worked in other companies. Maybe you have 10, 20, 30% even more other companies.

So two follow-ups here. One is just why do you think operating this way is more effective in the way in your business? And what do you need to hire engineers in a different way for them to succeed in this way where they're basically playing the PM role?

This works because you want to be as close to the problem as possible, and that probably works. being as close to the technology as possible, being as close to the users as possible. You can have it with two different people that have to interact and coordinate. And that obviously works as well. I'm not saying this is the only way to do it. Clearly, there are a lot more examples. Maybe we are actually the exception and it would be hard to replicate anywhere else. But if you're able to have that whole context in a single mind, in a single person that can then deliver that vision to the team, I think it leads to great products that users are going to love and enjoy. In terms of hiring, we do in the interview process, sort of like test for product skills, but we mainly do test for engineering skills. I think it's worth being honest about, like we have a strong bias for engineering, for being technical, for being deep into the details. There's not a lot of tolerance for being in a meeting and getting asked questions like, well, I need to check with this person to understand the details because, you know, I'm not sure what technology we're using. Like, that would not fly. So there is a bias towards the tech side of it. And then once you're inside Mercado Libre, you will probably get to know you a lot more and it'll be very clear if you have the product inclination or if you would be more comfortable just with the engineering.

What's really interesting about this is a lot of companies start with no PMs and they're like, we never need PMs. We're just gonna be engineers leading products. It's gonna be amazing. And then usually, eventually, people, these engineers realize, I don't wanna be doing all this bullshit PM work. I just wanna code. I wanna build. What am I in meetings all day writing specs? And it's interesting, you guys have scaled to a $100 billion market cap, 18,000 people on the product team, developers. and still you're working this way, it's really rare. What do you think has allowed you to operate this way at this scale that maybe other companies can't?

Yeah, I think it's also a top-down thing where a lot of the leadership is very technical. They're very into the product. They're also very into the business, into the numbers, into the details. It's amazing to be on the, C-level meetings and the kind of questions, the kind of level of attention. I know founder mode is now like a term that's there, but the company has been operating like that for a while now where discussions will even go as deep as, okay, why are we using that copy? That's way too many words. It's not clear. Hey, why is this pixel here where we could use that space for something a lot more useful? And these are literally conversations at the C-level. asking, okay, how does this work for users? When you present a feature, and here I'm going to stereotype other companies, it might not be the case, but my understanding is any time is okay, how much revenue can we get from this new feature? Or what's the metric that's going to move? For Marcos, our CEO, the first question is always, okay, how's the user going to experience this? Show me the flow, show me the user experience, are they understanding it, show me the metrics that people are actually liking what we're doing, putting the users before the revenue, obviously turns into revenue in the future, in the long term, which is what you're looking for. So again, I think the top down version of that, maintaining the culture and being able to select for the top of the top talent in the whole region, in multiple countries, I think it's what allowed that to happen. And the business, as you said, there's a lot of technology, right? You need to do the routing for all the buses, the trucks, the planes, the distribution centers, you need to routing for picking items within the distribution centers, risk, content moderation, search, robotics, all there's a really long list of really fun initiatives that we're working on. They're all very technical. turn into value for our users?

I can't help but ask, how does AI impact this way of working where engineers are doing more and more of the PM work? Is that just accelerating that further? Is there anything you can share about just how AI is changing the way you all operate?

It's a great question because you probably always hear it from the other side, like, okay, now people who are more product oriented are not going to need engineers as much. So for us, the change is accelerating, what people can do on both sides, but I don't think there's any competition. And again, we don't see a line between product and engineering as strongly as other companies. So I'm extremely happy when someone who's more product oriented comes in and can actually start developing more stuff on their own, even just demos. We can talk about the AI hype a little bit in the future, but it's definitely great to to make demos, to actually turn ideas into something that you can touch, something that you can see, designs, no, and seeing a lot more people enabled to do that, I think it's just accelerating everything we do. On the actual coding side, of course, it started as like advanced autocomplete, and now you have Agentic Frameworks and Cursor and Windsurf, OpenAI just made an acquisition. Clearly, it's sort of like a big shift in the way we develop technology. It's not at the point where it can sort of like do anything and everything and security, compliance, all the different things that go around actually turning a demo or a product into something that's going to reach the production or the market takes time. But I would say we're taking it even further. We always like to think in terms of platforms. It's one of the reasons why we've been able to scale the team so much. We have a great internal development platform that takes care of a lot of scaling, security, building, testing, compliance. So developers and teams can just focus on adding value. And we're taking the same approach with AI. We developed an internal platform called Verdi that basically abstracts away a lot of the complexities around, okay, where are you going to get the data? How is it going to be authorized? And that in itself has been evolving as the models become more capable. Now you can have more, what's called agents, agent frameworks, things taking action, taking over longer tasks. And we're seeing great results with skipping code entirely. I think it's a fun one where the prompt or what you actually want the product to do is everything. you tell a system, we came up with ways to use our existing code. So it's not like there's no code in any of what I'm talking about, but we basically can extract the functionality of every single one of our microservices, and then we can have agents build and use different parts of different services and create new features for users end-to-end with a UI. So that's something that is still experimental, obviously, but it's happening and it's just going to accelerate as the models get better. So we literally have things that are taking existing code. So it's not like code doesn't exist, but you don't have to write any new code. There's a lot of functionality that we already have on the platform, and you can combine different parts of it and turn it into a new feature or product without any intervention from any code, extra code.

That is very cool. So essentially you have all these APIs and microservices and your agents can just use what it already exists to add new features.

Exactly. And if you extend it a little more, you could even reach a point where UIs and apps are sort of like entirely generated. No, where it's like, okay, these are like all the things that you can do inside Mercado Libre. You can buy stuff, you can, get a credit card, you can move money around, and then have a completely personalized UI for a user predicting what are you going to do next, and then just having that as the main screen. Maybe you have other screens, obviously, that allow you to do everything, but it's an exciting future. I think we're going to see a lot more automated UI. Wow.

Okay. I'm going to try to resist just making every conversation about AI. So let's leave that aside and maybe we'll come back to it. But let's zoom out a little bit and I want to hear other key or very unique ways of working that you have figured out that allow you to operate this team of 18,000 developers and continue to ship great product. So if you had to pick, I don't know, two or three key ways of working, what would those be?

One big one, it's a cliche, but it's true, is the fear of failure. No, we actually empower our teams to make mistakes. Like no one's gonna get fired for.