Hi, I’m Guilherme Santiago,
a product designer based in São Paulo, Brazil.

I’ve worked on debit cards in four countries, investment products for the American market, platforms for content creators, and a payments platform that takes on legal responsibility for every transaction it processes.

These are products where mistakes cost something: money stuck in transit, a payment declined, a charge nobody understands. A good part of my work is reducing the odds of that happening.

Access my resume
Guilherme reviewing a layout on a laptop, in a blue duotone portrait.
  1. Now, at Afya,

    I work on electronic medical records at Afya. It’s the system a doctor uses across the entire workday, with the patient sitting right there, and it’s used by very different kinds of professionals. I’m at the start of this journey, still in discovery, learning how the product works today and how people work inside it. I don’t have results to show here. We’ll see what comes.

    Present

  2. Guilherme at his desk, typing, with a monitor and a laptop open in front of him.

    Just before that, building alone at PagAmerican,

    I was the first and only designer at PagAmerican, the company’s fourth hire. It’s a global payments platform that operates as a merchant of record and takes on legal responsibility for every transaction it processes. I came in to build everything from zero to one. Design system, checkout, integrations, platform flows, all of it started on a blank page. Along the way I took on seats that weren’t mine because they needed taking: I wrote product requirements, opened PRs in engineering, created working rituals the team didn’t have. That’s where I settled into being a generalist. The line between design, product, and engineering turned porous and I started working inside it, and I got on with it.

    2025

  3. Guilherme in a white cap, resting his chin on his hand at a table with a closed laptop.

    A little earlier, at Inter&Co,

    At Inter&Co I designed investment products for the American investor, with screens and flows in English and Spanish. The hard part was deciding which financial concepts needed a different explanation for someone reading in a second language and coming from a different investing culture. A term that’s obvious to a Brazilian investor isn’t obvious to an American, and the reverse holds too. It was the first time I worked for a market outside Brazil, and it forced me to test assumptions I’d never had to test: about vocabulary, about risk expectations, about what a person assumes they already know before opening the screen.

    2024

  4. Guilherme sitting on wide wooden steps with a group of colleagues.

    Before that, across four countries at Mercado Livre,

    I had the opportunity to work on the Mercado Pago app, creating end-to-end experiences for millions of users in Argentina, Mexico, Chile, and Brazil. By understanding the needs and expectations of users in a B2C environment, my main focus was designing flows by analyzing various cases and their respective impacts in depth prioritizing excellence in storytelling and minimizing product friction.

    Designing in a localized manner challenged me to understand the cultural nuances of each country. This experience taught me the importance of scalable and adaptable solutions.

    2022

  5. Guilherme seated inside the round opening of a large orange sculpture at the Hotmart office.

    In nearly 6 years at Hotmart,

    my journey spanned about 7 teams, where I was able to capitalize on knowledge and grow with the company. I worked on creating internal products that helped the company become more profitable, redesigning the information architecture of the help center—contributing to CX efficiency while reducing user pain points—and also on payment systems and designing exceptional experiences for B2B market users.

    By helping companies boost their digital businesses and achieve significant results (an experience that was fundamental in consolidating my product design foundation), I had the mission of dedicating myself to result-oriented deliveries, with a strong focus on testing and experimentation as value drivers for the customer throughout their journeys on the platform.

    I worked on projects ranging from onboarding new users to creating growth loops to increase activation and retention. Additionally, by becoming a company reference, I contributed to creating playbooks and onboarding processes for new employees, sharing knowledge about users and their journeys.

    2017

Guilherme holding up one of his paintings: a figure seen from behind, in warm browns.

And outside of all that

Over the past few years I’ve developed a genuine curiosity about painting in my free time. It came out of my appetite for decoration, for artwork, for the objects that make up the space where I live day to day, especially from working remotely for almost seven years.

I read a lot. Among books, the technical ones about design pull me in the most, mainly because it’s a field in constant change and adaptation: there are things you only improve in yourself, and in the way you work, by studying them. Beyond the technical books, I read on Medium and I’ve developed an appetite for writing about what I learn in my career, and I recognize I should do it more often. I promise to try. But I also like history books, chronicles, and Brazilian writers who write about their own obsessions and about art.

That connects to my passion for music, where my taste runs wide, from MPB to disco, which takes me dancing and to clubs and festivals all over the world. I like going out with friends, planning trips, and exploring the world beyond the Instagram explore tab. Building your own repertoire is a minimum survival requirement for any designer. Getting to know other cultures, other food, other languages takes me to a lot of places, and above all it feeds the intrinsic motivation that gets me out of bed every day: curiosity. Being curious. Working at Mercado Livre from day one in a language I didn’t command, and building fluency very fast, made me see that even more clearly. I ended up living in Argentina for a month, on my own, with no incentive from the company, to do a deep dive into the language and get to know my team, which is mostly Argentine.

The pandemic developed my abilities in the kitchen quite a bit, and with them a passion for eating well, for being healthy, for physical activity, crossfit among them. Working remotely also allowed me periodic trips to get to know countless places, balancing work and mental health in a very favorable way. And, despite all of that, having a home: cultivating my family and my recent pets, who came in the love package, my cat Gatão and my dog Lulu.