Stark Bank's API-banking bet: Bezos-backed in 2022, R$600B moved by 2025

An API-first digital bank for mid-size and large Brazilian companies: corporate accounts, Pix, payments, payroll, corporate debit and credit cards and accounts payable/receivable automation, plus Stark Infra, a unit selling its banking technology to third parties.

Medium and large Brazilian companies would run corporate banking through APIs with programmable control - payments, cards, payroll and approvals - not branches.

Bootstrapped with nearly R$1M from founder's previous startup, then $500K from angels and a $2M seed

Rafael Stark, an ITA-trained engineer who had built Android apps and founded Hummingbird after returning to Brazil in 2014, started Stark Bank in August 2018 with money from that earlier company. His trigger was a developer's gap: he was used to integrating Google Maps and Twitter APIs, yet found no bank in Brazil offered one - and he called the incumbent payments system archaic. He piloted an API for transfers and, by 2019, was handling nearly every transactional part of banking through APIs.

Stark Bank obtained a direct credit corporation (SCD) licence in October 2020 - which the company called a first for a seed-stage fintech - and raised a $13M Series A in December 2021 led by Lachy Groom, with founders of Coinbase, Dropbox, Flexport, Figma, Rappi, dLocal, Wildlife and Slack participating. Four months later, in April 2022, Ribbit Capital led a $45M Series B joined by Bezos Expeditions - the Amazon founder's first investment in Brazil - plus SEA Capital, K5 Global and founders of Airbnb and Kavak, leaving Stark Bank with $58M in cash. It served more than 300 'new economy' clients such as Loft, Buser, Daki, Cora and Bitso, had already broken even, and was moving into corporate credit.

The model kept compounding: Stark Bank said in February 2024 that it processed R$155B (about $27B) in payments during 2023 - a threefold jump - while net income more than doubled to R$71.5M, and by March 2025 it served roughly 800 clients, including 52 crypto-focused firms. It transacted about R$600B in 2025 and set a R$1T target for 2026, counting Ambev and iFood among clients. As of April 2026 it was still scaling: a full Brazilian bank licence filed in December 2023 remained pending, a licence abroad was sought for 2027 operations, and an IPO in the United States was planned on a five-to-ten-year horizon.

The wedge matched a real underserved job: Brazilian developers and finance teams had no API to automate payments, refunds and payroll, so early customers pulled the product roadmap themselves.

It aimed at companies, not consumers, betting that control features - approval rules, per-category spending limits, audit trails - would beat convenience in B2B banking.

Profitability came before the big rounds: breaking even early let Stark Bank scale on its own numbers and attract investors like Bezos Expeditions without a forced growth narrative.

The central bank's open-finance and Pix mandates turned regulation into tailwind: API-native infrastructure became the compliant way to plug into Brazil's real-time payments system.

Sell the integration your customers already want: Stark turned one developer's API pain into payroll and cards, then followed client requests into a full bank while staying profitable before scaling.

As of April 8, 2026, Stark Bank is a profitable, privately held corporate digital bank in Brazil that transacted about R$600B in 2025 and targets R$1T in 2026. Its roughly 800 corporate clients include Ambev and iFood. Founder Rafael Stark told CNN Brasil that its full Brazilian bank licence (filed December 2023) is still pending, that it applied abroad to start operations in 2027, and that it is capitalized enough to skip further funding rounds; a US IPO is envisioned in five to ten years.