Frontend, SEO, CRO, Martech

Interfaces that make sense.

I'm Wesley Luiz Carvalho, a Front-End developer. I build fast, accessible digital products, from code to SEO, to turn good ideas into experiences that convert.

Let's talk View works

ABOUT

The person behind the code.

I've been a front-end developer for over 5 years and I build complete digital products: from code to performance, from accessibility to SEO, from measurement to experimentation, always turning ideas into fast interfaces and real results.

I've been through the full cycle of digital products at Santander Brazil: from publishing campaigns via CMS to building pages and layouts, and running experimentation: more than 60 experiments and personalizations with Adobe Target and Oracle Maxymiser, with a success rate close to 64%.

Working closely with design, product and business made me want to understand not only how things are built, but why they exist. Today I combine technical depth, accessibility and performance (with Lighthouse above 90) to continuously improve the user experience.

  • HTML
  • CSS
  • JavaScript
  • TypeScript
  • React
  • Next.js
  • Tailwind
  • On-Page SEO
  • GTM
  • GA4
  • AI
  • Azure AI-900

My experience

Front-End with a focus on CRO, performance and Martech: from campaigns and portals to experiments that deliver results.

EDUCATION

  • Bachelor's Degree in Computer Science

    Universidade Paulista (UNIP), 2016 – 2021 | São Paulo, Brazil

  1. Front-End Developer / CRO

    –

    Math Group, assigned to Santander Financeira | São Paulo, Brazil

    • Planned and implemented more than 60 digital experiments and personalizations using Oracle Maxymiser and Adobe Target, reaching a success rate close to 64%.
    • Strategic CTA repositioning on an insurance product, resulting in a nearly 48% increase in the conversion rate.
    • Optimized the vehicle financing journey, increasing by about 5% the number of users who advance to the offer.

  2. Front-End Developer

    –

    Math Group, assigned to Santander Brazil, Digital Business | São Paulo, Brazil

    • Developed campaign pages, web stories, and new layouts for the Santander Brazil homepage, including the Blog Dark Mode, the Santander Select page, and the Divide o Pix page.
    • Built responsive, cross-browser compatible interfaces with HTML, CSS, JavaScript, Bootstrap, and React.
    • Continuous performance, accessibility, and SEO optimizations, improving loading efficiency and organic visibility of pages.

  3. Support Analyst

    –

    Math Group, assigned to Santander Brazil | São Paulo, Brazil

    • Updated and swapped campaigns on the Santander Brazil institutional website and mobile app, following technical specifications for images, formats, and copy.
    • Published and managed content via Oracle CMS, ensuring technical compliance and visual consistency across pages.
    • Ensured quality and consistency of digital campaigns across all channels, within established deadlines.

  4. IT Intern (Web Development)

    –

    Itaú Unibanco | São Paulo, Brazil

    • Technical support for corporate intranet portal users and web page development with HTML, CSS, and PHP back-end.
    • Queried and manipulated data in SQL Server, and analyzed and handled tickets through the Maximo (IBM) system.
    • Took part in process improvement projects using Kaizen and Six Sigma methodologies, within an agile Scrum squad using JIRA.

03 / How I can help

Services

01

Front-End

Fast, accessible, and scalable interfaces built with HTML, CSS, JavaScript, Next.js, TypeScript, and Tailwind CSS.

02

Martech & SEO

Measurement architecture, GTM, GA4, and on-page SEO directly connected to business outcomes.

03

Conversion & Data

I analyze user behavior to uncover real growth opportunities, not just vanity metrics.

04 / Selected Works

What I have built

Santander Select page

Santander Brazil · 2021 – 2024

Santander Select institutional page, with a carousel and SEO metadata implemented to improve organic traffic.

  • HTML5
  • CSS
  • JavaScript
  • Bootstrap
  • Slick
  • GTM
  • SEO

Santander Blog Dark Mode

Santander Brazil · 2021 – 2024

Dark mode for the Santander Blog built without any framework, using only plain JavaScript and CSS.

  • JavaScript
  • CSS

Santander Webstories

Santander Brazil · 2021 – 2024

Santander Web Stories built with the Google AMP framework.

  • Google AMP

Agência Byte (View site)

Corporate website

Corporate website for Byte Ag, a digital marketing and technology agency. A static project with no build step and no backend dependencies.

  • HTML
  • CSS
  • JavaScript

EMPL (View site)

Corporate website

Website for Eletro Mecânica Presidente (Osasco, Brazil, since 1983), which repairs and rewinds electric motors, water pumps and power tools.

  • Corporate website

Luann Batuira, photographer (View site)

Portfolio

Portfolio for architecture photographer Luann Batuira, as a static, fast, SEO-ready site of their own, replacing the version hosted on Canva.

  • Static site
  • SEO

LUMINA Moisturizer (View site)

Study project

Fictional product page for the LUMINA Moisturizer, created to study SEO, AEO (Answer Engine Optimization) and an LLM-ready structure.

  • SEO
  • AEO
  • LLM-Ready

05 / Next step

Have a challenge?
Let's build it.

If you need a better interface, data that truly explains user journeys, or a technical partner to bring ideas to life, reach out.

© 2026 Wesley Luiz Carvalho. All rights reserved.

Built for the web.