back
MELLRO
EXTENDED version
About the company
Mellro built a three-sided rental marketplace connecting owners, tenants, and brokers in Brazil. A payment-guarantee structure cut repossession from over a year to about a week and opened renting to people the old guarantees excluded. Venture-backed.
—
Tags
Owners kept properties empty out of fear. We rebuilt the guarantee, and cut repossession to about a week, against the year-plus an eviction takes.
I joined Mellro as Lead Product Designer, leading product and design, and I was there before there was a team. What started as a founder's idea became a three-sided rental marketplace with more than R$140M in contracts under guarantee, and I structured the product that made that possible: the features, the processes, and how the company thought about building. When I came in there was no backlog, no MVP, no flows. Just an intuition and the will to build. This is the long version, with the full context, the mechanics of each part, and how the pieces worked as one system.
The short version of the problem: renting in Brazil was stuck because a standard eviction took a year or more, so owners kept properties empty out of fear, tenants were excluded by guarantors and deposits, and brokers drowned in fragmented tools. The fix was changing the legal and financial structure underneath the whole transaction.
Context and problem
Renting in Brazil was defensive by design, and everyone in the chain paid for it.
The root was the law. A standard eviction under Brazil's Tenancy Law took twelve to eighteen months, sometimes longer. That single fact shaped every behavior around it. We saw it directly and often: whenever we brought on a client that already managed a rental portfolio, the same story came up, owners who had left a property sitting empty on purpose, because a bad tenant could mean a year of lost rent and no way to remove them. They preferred an empty apartment to a risky one. The market had organized itself around avoiding a worst case instead of enabling a normal one.
The three sides of the market each felt it differently. Owners faced months of vacancy or the risk of a year-long eviction, so many simply left properties empty. Tenants were shut out by the guarantees meant to protect owners: a guarantor who owned property in the same city, or three to six months of deposit upfront, which pushed qualified families with stable income into the informal market, renting without a contract or legal protection. And brokers juggled listings, contracts, and guarantees across five to seven systems that didn't talk to each other, took the blame when something broke, and lost commissions and clients over it.
There was a quieter problem underneath, and it turned out to be the important one. Many brokers didn't work with rentals at all. Not only because the tooling was bad, though it was, but because managing a rental portfolio was genuinely hard and thankless: the ongoing administration, the risk, the friction between owner, tenant, and broker. Sales was cleaner and paid faster, so brokers avoided rentals. If Mellro wanted reach, it couldn't just digitize the existing process. It had to remove the reasons brokers stayed away in the first place.
How I got to the product
The founder's original idea was a Tinder-style match between brokers and tenants: swipe, connect, done. I tested it through discovery, running interviews with brokers, owners, and tenants, going to industry events to understand how the market actually thought, and building and validating against real deals rather than assumptions. Discovery, it turned out, wasn't the problem. Matching a tenant to a property was the easy part. Everything after was where deals died: guarantees, contracts, payments, risk, and the long administrative tail that made brokers avoid rentals altogether.
That reframed the question for me. The real barrier to growing this market wasn't discovery and wasn't only tooling. It was the accumulated complexity that made a rental portfolio not worth a broker's time, and a chunk of that complexity lived in how the relationship between broker, owner, and tenant worked in the eyes of the law. The legal structure was one of the main things keeping brokers out, and it was the same thing making owners keep their properties empty.
The founder had the legal hypothesis, a way to restructure the product so the law worked differently. A hypothesis isn't a product, though, and turning it into one was the work I owned. My contribution was two things: understanding why the legal complexity mattered so much, that it was a root cause of both broker avoidance and owner fear rather than a compliance detail, and then building the product that made it real, structuring the features, the flows, and the way the company thought about product from the ground up. Structuring the legal core itself was cross-team work with the founder and a legal consultancy. Making it into something the three sides of the market could actually use was mine.
WHAT I BUILT
I led product and design, and for the early stretch I was the only product person there, structuring the foundation before there was a team to share it with. Later a designer joined, working alongside and reporting to me, and we often built side by side. The system came together as three moves, one for each side of the market, plus the operational layer that let it scale.
The legal reframing, made usable (owners)
Instead of operating as a rental guarantee under the Tenancy Law, we structured the product as a payment guarantee under different legislation. That distinction is the whole foundation. As a payment guarantee rather than a rental one, we operated under a different regime than a Tenancy Law eviction, which is what let us cut repossession from the twelve to eighteen months a standard eviction takes down to about a week.
For the owner, that changed everything downstream. We could take on the default risk ourselves with a sustainable model, pay the owner whether or not the tenant paid, and drop the guarantor and large deposit requirements entirely. The owner who used to leave a property empty out of fear now had a guarantee that removed the fear. My work here was turning a legal structure into a product a normal owner could understand and trust in a few screens, hiding the legal machinery behind a simple promise: you get paid, on time, regardless.
Modern risk analysis (tenants)
Traditional guarantees excluded anyone without a guarantor or three months of deposit, which meant excluding a lot of people who could clearly afford the rent. We replaced that with an analysis that weighed broader signals: credit history, income stability, income-to-rent ratio, and, crucially, informal income.
That last signal mattered most, because in Brazil a huge share of stable earners are informal, and the old model treated them as invisible. By reading informal income, we approved renters that guarantors and deposits would have turned away, with a transparent reason whenever the answer was no. The approval rate landed around 90%, an internal KPI I tracked, and every approval was a family that got a formal contract instead of the informal market.
Full assumption, zero fee (brokers)
This is the piece that addressed the real reason brokers avoided rentals. They paid nothing to use the platform; our revenue came from the guarantees themselves, so brokers kept 100% of their commissions. More important, we absorbed the work that made rental portfolios miserable to manage and used to fall on the broker: the payment guarantee to the owner, collection, legal support, and standardized contracts generated automatically.
That removed the administrative tail that kept brokers in sales and out of rentals. They could finally build a rental portfolio without it becoming a second job, and without being the one blamed when a payment slipped. Underneath it, I designed a universal registration: a single source of truth where a property is entered once and replicates to listing portals, payment splits, commission config, inspections, and digital contracts. Brokers used to re-enter the same property across five to seven systems; now it was one. Registration dropped from around two hours to about fifteen minutes, and an independent broker suddenly operated at the efficiency of a large agency.
The operational layer
A guarantee business only works if operations scale without headcount scaling with it, so I set that as a principle early. We built an admin platform that gave each internal team, CS, Finance, Legal, and Risk, the ability to act on data directly, without going through engineering for every change. Receivables anticipation, which let brokers draw working capital against future commissions through a R$65M credit line, lived here too; that piece sat more with the designer working alongside me, and I helped structure it. The result was an operation that went from dozens to thousands of contracts without the team growing at the same rate.
What I got wrong
The first version was built around a chat screen. We wanted the conversation to happen inside the tool on purpose, since an in-app record gave us stronger legal footing if a contract was ever disputed. Users didn't cooperate. They moved to WhatsApp, the way everyone in Brazil eventually does. We gave up the legal advantage we'd designed for and redistributed the whole navigation around how people actually behaved. The lesson stuck with me: a real business reason to want a behavior, even a good one like legal protection, doesn't make users adopt it. When I structure a product now, I design for how people already act, and find another way to get what the business needs.
Results
Independent brokers who had spent fifteen years only in sales built rental portfolios for the first time, because the work that used to make rentals not worth it was gone. Families with stable but informal income, the ones the old guarantees rendered invisible, rented formally, with a contract and legal protection. And owners who used to leave properties empty had a reason to put them back on the market.
By the numbers, the platform reached more than R$140M in contracts under guarantee, with an approval rate around 90%, registration cut from about two hours to fifteen minutes, and a R$65M credit line backing receivables. The company raised R$6.5M along the way. The market noticed too: traditional agencies started coming to simplify their own operations, and the press nicknamed us "the XP for real estate brokers," after the brokerage that made investing accessible to ordinary Brazilians. Flattering, and closer to the point than the label we'd given ourselves.
When I moved on, I trained the product team that succeeded me, so the work continued without depending on me.
What I learned
Systemic problems don't yield to one layer of solution. If we had only built a cleaner interface, we would have failed, because the thing keeping this market small was the accumulated legal, financial, and operational complexity that made rentals not worth a broker's time and made owners afraid to rent at all. What unlocked it was seeing that the real barrier was structural, then making a legal reframing, an automated operation, and a financial model work as a single system. The job was to find where the real wall stood, and much of it was invisible, before drawing anything. I was the one who had to turn that understanding into a working product, most of the time as the only product person in the room, and that is the part I am proudest of: not the idea, but the building.
FACT SHEET
Role: Lead Product Designer, leading product and design. First product hire, structured the product foundation from before there was a team.
Period: 2020 to 2024
Context: Three-sided rental marketplace, Brazil. Venture-backed; raised R$6.5M.
Scope: Led product and design from zero. Field discovery, MVP and roadmap, the payment-guarantee product, risk analysis, universal registration, admin platform for internal teams. Structured the product process and trained the product team that succeeded me.
Team: Solo product person early on; later a designer working alongside and reporting to me. Worked directly with the founder and a legal consultancy on the legal core.
Ways of working: Remote, documentation-driven, cross-team with legal and engineering.
Domains and keywords: fintech, marketplace, three-sided marketplace, payment guarantee, risk analysis, receivables, product leadership, zero to one, design systems.
Outcomes: R$140M+ in contracts under guarantee; repossession ~1 week versus 12-18 months for a standard eviction; approval rate ~90%; registration ~2h to ~15min; R$65M receivables credit line; R$6.5M raised; trained the succeeding product team.
