About Me

Hello! I'm Marlon Brandão de Sousa, a software engineer based in Curitiba, Brazil. I have worked in technology since 2004, and for much of that time on the systems that move people's money: internet banking, international remittances, and cross-border payments.

I am also a blind developer, a conference speaker, and a digital accessibility advocate. Those two halves are not separate careers. Building financial software that people trust — and that everyone can actually use — is the same problem approached from two directions, and it is the work I care most about.

If there is one thread through all of it, it is that I like being a layer down. The framework rather than the screen, the harness rather than the feature, the add-on rather than the app — the part that makes other people's work possible and rarely gets the credit. I have been working on the same question, how technology includes people, since around 2005, and I have changed tools constantly without ever changing the question. I also think mainly by explaining: if I cannot write something down for someone else, I probably do not understand it yet. And I ask for help without embarrassment — from colleagues, from an AI agent, from a stranger at a crossing — because refusing help to protect your ego makes you worse, your software worse, and the world worse.

Away from the keyboard I am a Christian and a husband, and my family comes before the rest of this page. I sing, I read, I play the trumpet, and I travel as much as I can manage — enough that my wife Atena and I spent several years makingBlindando, a podcast about tourism and having fun from the point of view of us blind people, with episodes from Havana to Machu Picchu to Stockholm. Most of what I enjoy comes back to the same thing the work does: helping people.

Professional Experience

• EBANX — Engineer Specialist (Aug 2024 – present): One of Latin America's largest fintechs, and the cross-border payments infrastructure global merchants use to sell into the region. My work has two tracks. The first is research into AI for software engineering — how agents earn a place in a production engineering organisation rather than a demo, including extensive use of Cognition AI's Devin, which took me toCognition's Champions Summit in San Francisco in June 2026 as one of twenty users invited from around the world. The second is writing the base frameworks other teams build on, so that engineering operations are something the platform provides rather than something every team reinvents.
• Remessa Online — Staff Engineer (Nov 2022 – Jul 2024): International money transfers, on the platform that moves funds across borders for individuals and businesses. Beyond the platform itself, I built enablement products for other engineering teams, and advised senior management on engineering needs and where the largest improvement opportunities actually were.
• EBANX — Senior Engineer, and Chief Engineer at Compass (Aug 2019 – Oct 2022): During an earlier spell at EBANX I led engineering at Compass, its banking operation in the Turks and Caicos Islands, licensed there as Compass Trust Ltd. I set up the entire banking system: accounts, card management, statements, the credit card authoriser, back office, customer service, and file processing. All of it in Rust, all of it on Kubernetes. At its height the Compass card served close to ten thousand people in and from the islands, many of whom did not qualify for a card from an established commercial bank.
• Itaú Unibanco — Internet Banking Platform (Mar 2011 – Jul 2019): Development and evolution of the framework behind the internet banking of Brazil's largest private bank, along with maintenance of the internet banking core system and the design of interoperability layers between systems. I also advised mobile and internet banking front-end teams on accessibility.
• Accenture — Senior Software Developer, then Analyst Programmer (2008–2011):CMMI level 5 audits on ABAP projects, turning audit findings into process improvements, and later supervising the audit team — training auditors and building the tooling the organisation's quality and engineering processes ran on.
• Rede Globo — Software Developer (2004–2008): Research and development for Brazil's largest broadcaster: prototyping and evaluating new technology against the station's internal demands, presenting the resulting projects, and helping establish a basic software development process.

Talks & Interviews

• Cognition Champions Summit — Cognition's headquarters, San Francisco, June 2026. For its first Champions Summit, Cognition brought together twenty of its top Devin users from around the world — teams already running Devin in production on migrations, internal tooling and automation — for a day of workshops on the workflows that matter most to each of them. I was one of the twenty, and I speak in thesummit video, from 1:49, about what made the day useful: sessions where the real problems with the product were discussed as openly as the solutions we had found for them.
• AI agents in production — second EBANX Engineering Meetup, Curitiba, November 2025, co-presented. On the mature and strategic use of AI agents in an engineering organisation: what we measured, why it is not another hype cycle, and a live build of a tested service in fifteen minutes. The meetup was not recorded, so the talk is written up as“AI Agents are Not Hype: They are Driving Core Business Value at EBANX”.
• “Escolhi uma plataforma para desenvolver. E agora?” — Accessibility track, TDC Florianópolis, 2018.Speaker profile.
• “Programar sem enxergar” —Hipsters Ponto Tech #82, February 2018. A conversation on whether, and how, you write software without sight.
• “Como cegos desenvolvem software: da concepção à implementação” — DevDay, Belo Horizonte, September 2017.Video on InfoQ Brasil.
• “O protagonismo dos deficientes visuais na área de tecnologia da informação” — Digital Accessibility track, TDC Porto Alegre, 2017.
• “Como deficientes visuais desenvolvem software — da concepção até uma implementação prática” — Digital Accessibility track, TDC Porto Alegre, 2017.
• podProgramar — interviewed onone of Brazil's best-known programming podcasts.
• BlindTec — nearly a decade of articles, tutorials and podcast episodes on assistive technology, in myauthor archive.

Speaking & Community

• Founder & Editor-in-Chief — BlindTec: I created and leadBlindTec, Brazil's leading portal and podcast for assistive technology, publishing technical articles, tutorials, and interviews on screen readers, software accessibility, and tech careers.
• Track Coordinator — The Developer's Conference (TDC): Coordinator of the Accessibility track at TDC São Paulo in 2018, and a speaker at TDC and DevDay across several years. The talks are listed above.
• EasyWay — second place, FIAP StartupOne: With a designer and two other engineers, I built the prototype of an indoor location system to help people find their way through complex venues such as expo centres, shopping malls, and stadiums.

Areas of Interest

In the order I currently care about them:

• AI Applied to Software Engineering: What it takes for an agent to produce software professionals can actually depend on — specifications, architecture set up front, fast feedback loops, and gates the agent can check itself against. This includes Model Context Protocol servers such as screen-readers-mcp, which let agents drive screen readers to run automated functional tests, bringing real coverage to software that has historically been checked by hand, if at all.
• Banking Development: Core banking, card authorisation, ledgers, and payments — correctness, reliability, and trust in systems where being wrong costs somebody real money.
• Rust Development: My language of choice. I am interested in the case that Rust is not only for systems work — that you can write command line tools, services, and desktop applications in it at a high level of abstraction and still get the performance, the deployment story, and the safety guarantees for free.
• Open Source Development: Building in public, mostly assistive technology: NVDA add-ons, screen reader ergonomics, and tools the accessibility community can pick up and use without asking anyone's permission.

Education

• Postgraduate MBA in Mobile & Game Development (2016–2017): FIAP
• Technologist in IT Management (2011–2013): Unisul
• Technical Diploma in Data Processing (2002–2003): Etec Lauro Gomes

Explore the Site

• Read my articles and article series on the Blog.
• Discover my open-source projects on the Projects page.
• Download the latest add-on builds on the Releases page.
• Search all content using the Search page.

Get in Touch

The best way to reach me is email: contact@marlon-sousa.com. Questions about anything I have written, corrections, or an accessibility problem you have run into — all welcome.

You will also find me on GitHub, where the issues and discussions are open. And every article here has a comment box at the bottom, if you would rather say it where other readers can see it.