What I build, published on Stickybit.
Each card opens a Stickybit section, in that section's own colors. Every one has a demo you can play with, the measurement with its source, and a list of what could still be wrong.
AI assistants already choose where to buy by reading a store's HTML. I show what the assistant gets from yours, item by item.
TUBE, SIEVE and five more tools that compress, search and timestamp sensor data with a guarantee anyone can check.
What the quantum computer breaks, when the estimates say, and what switching costs.
A live encrypted election and 16 tests on where computing blind works, costs or stalls.
Essays with a specimen to play with, before anything becomes a product.
A tech news portal moved from PHP/Zend with an embedded ad server to Go. The gain came from no longer carrying third-party code, not from shorter code.
Visual search over ~100k watch parts. The first fix came before the algorithm: the camera only fires when the part fills the frame.
Eight directories, one Go binary each.
My own products: local guides in Brazil, Mexico and the US. I write the data pipeline, the storage, the pages and the editorial content. Each case page tells how it was built and what it measures.
Twenty-six years, the same kind of question.
The technology changed many times. The question did not: scale without breaking, cost less, and know when the number is wrong. Stickybit already existed before 2015; from then on it became my main work.
- 2000–2002
Hospital Municipal de Parobé
My first big system: hospital administration for a public hospital that served about 75% of the Azaleia factory's workers.
VB6 · SQL Server - 2000–2004
PlugIn, later UOLHost
Full hosting automation — DNS, email, web and databases. Opening a hosting account went from 24 hours to 1 minute. The first ISP e-commerce in Brazil, and an industry innovation award.
Perl · PHP · BIND · Postfix · Apache - 2004
Companhia Província
Contract synthesis for a real-estate lender: several legacy databases unified behind one web interface.
PHP · SQL Server - 2005–2015
UOLHost analytics
Log analytics for thousands of hosted sites a day: 85k lines of Perl, more than ten years in production.
Perl · batch - 2006
Hospital de Clínicas de Porto Alegre
Real-time bed control for one of Brazil's reference university hospitals.
PHP · MySQL - 2008–2015
Tevah tailoring franchise
One system from store to factory to franchisor, for seven years. The network grew from 8 to 46 stores.
Perl · PHP · MySQL · Flash - 2012–2017
Dinamize · director
Rewrote the email platform in Go, before Go 1.0: 67 systems, own MTA, DNS and queues. From 600k to 23 million emails a day (38×), with costs down 67%. Stickybit kept running in parallel.
Go · custom MTA - 2015– today
Stickybit · main work
Mailbiz Analytics and Impulse (24 e-commerce platforms, 1,000+ stores). WebContinental: a Black Friday proxy that let 14 tills share one TOTVS license (2019) and an own shipping engine in 67 days (2020). Baguete, Calibr, the directories, and the sections now on stickybit.com.br.
Go · PostgreSQL · LevelDB
Notes from the bench, with the numbers attached.
- AI · ENForcing AI Honesty Through IterationA binary verification loop that makes the assistant actually finish the task.
- AI · ENThe Future Has No ScreenVoice replacing visual interfaces — and how I already use it every day in the terminal.
- AI · 2025The AI Pushback ProblemWhen assistants refuse to help, and the growing skepticism among developers.
- AI · 2025Why AI Gave Me the Wrong AnswerThe premature-optimization trap, and how to get better answers.
- Tech · 2025Stack Overflow Has Become a MuseumWhat its decline means for developer communities.
- HiringThe Great Exclusion: AI RecruitmentHow automated hiring filters out qualified people.
- WorkFractional CTOSenior technical leadership, part-time.
- Data · 2025TabNews 2025 RetrospectiveA year of the Brazilian developer community, in data.
- Data · 2025DEV.TO 2025 Analysis1,600 articles read; AI took a third of them.
- Data · 2026E-Commerce Intelligence BrasilThe digital presence of 7.2 million businesses in 500 Brazilian cities, from Overture Maps data.
The Models Race, counted on Hacker News.
How often each model family was mentioned on Hacker News in 2025. I went through 4.78 million items from 176 thousand users. In practice: Claude was the name that grew most in the conversation — which measures attention, not quality.
Four habits, no slogan.
Measure before promising
Every number that goes on a page comes with the source, the date and a way to redo the math. Someone else's estimate shows up as an estimate, with their name on it.
Publish the correction
When one of my numbers was wrong, the page says what it was, what it is and why. It happened with vibration compression and with the scale of certified search.
Fewer parts
Go, a relational database and pages that arrive ready from the server. Every dependency is one more door to watch; the Baguete migration removed 2.3 million lines of them.
Let the client check
The checker ships with the system. Whoever receives the data, the report or the vote can verify it without having to trust me.
Tell me the problem. I'll tell you if it can be measured.
No ready-made package. First I understand what you need to prove, and to whom. If it is not a job for me, I say so in the first reply. English or Portuguese.
Porto Alegre, Brazil · UTC−3 · I reply within one business day