Web development · Application security
This page isn't an example of my work: it is my work. Load it, look at all of it, and if you like how it works, that's exactly what I build for your business.
Evidence
Six things this very page does, and yours would do the same. These aren't promises: they're its real numbers, measured on every release. If one gets worse, it shows up worse.
29.1 KB An average page weighs 2,000–3,000 KB. This one weighs 29.1.
0 KB There are no scripts to download and wait for. The text is there from the first moment.
84 KB That's my photo. The original was 722 KB — nine times heavier, to look the same.
18:1 The text contrast. The international standard asks for 7:1 at its highest level.
2 Languages, each with its own address. The previous site hid the English where search engines couldn't see it.
0 Scripts allowed. The security policy blocks every one of them, and it's verifiable.
Want to check? Press F12 and look at the Network tab. Or run Lighthouse on it.
Services
One person accountable for the whole cycle. No designer blaming the developer, developer blaming the host, and nobody answering for the result.
They leave before seeing what you sell, and you never find out they were there. I build in static HTML served directly, so the first screen shows up with nothing delaying it. That matters more than it sounds when a good share of your visitors arrive on a phone with limited data.
The expensive failure isn't being attacked: it's one client seeing another one's information. I enforce isolation in the database rather than only in the code, so a query that forgets to filter returns nothing instead of returning what it shouldn't.
Reviewing it at the end means finding the problem when fixing it costs ten times more. Headers, content policy and tested authentication go in from day one, not as a farewell audit.
Plenty of projects die finished and unreleased. I close with the site live, working, and with a way to know whether it's doing anything for you. A site nobody measures is a site nobody learns from.
Portfolio
I built one from scratch; the other I migrated without losing a single indexed URL. Open them, read their source, run whatever tools you like on them.
8 pages · structured data with pricing · static HTML
My agency's commercial site. Public pricing, one page per service with its own search intent, and structured data that lets Google show the figure in the result itself. Zero JavaScript shipped to the browser.
55 indexed URLs · 41 intact · 11 redirected · 3 retired
Migration of a jiu-jitsu academy from WordPress to static HTML without losing a single indexed URL, checked against the published site. Six were neither declared in the sitemap nor found by the crawler: they surfaced when the inventory was cross-checked against Search Console, and two would have become 404s.
Method
Eight phases, each leaving something verifiable behind. That's what separates knowing several things from improvising at all of them.
What problem needs solving, and how we'll know it was solved.
What the best in the field do. You don't reinvent what's already solved.
Colour and type system with calculated contrast ratios, not estimates.
Test first, code after. The test defines what should happen.
Automated, plus a security review.
Speed, accessibility and search visibility, with numbers.
Reproducible deployment, not "it worked on my machine".
What got measured gets fixed. Then measured again.
About
I'm Rómulo Felizola. I worked as a backend developer at Aion Team (Barcelona, remote) from December 2023 to February 2025: production applications, databases, API integration and fixing real vulnerabilities — input validation, access control, authentication.
Today I run JS Brand Lab, where we build complete digital presence for businesses. This page is the proof of concept for what we sell: if I can't build mine well, I shouldn't be building yours.
I live in Venezuela and work remotely with clients in Spain, the United States and Latin America.
Spanish native · Portuguese C1 · English B2 · Italian B1
Contact
If what you've seen here is what your business needs, that's where the packages live — public prices, delivery times, and what they don't include. And if you'd rather talk to me first, before looking at prices, just write.