David Guerreiro

WordPress & JS Developer

Hi! I'm David Guerreiro, a professional WordPress Developer, enthusiastic JavaScripter and amateur Game Designer and Developer. I have always enjoyed playing and experimenting with technology, user interfaces and game mechanics, so I decided to do what I love for working too!


WordPress Development

I have been building sites using WP as my main CMS for more than 3 years. When I have to approach a new theme development, I take advantage of using the WordPress Theme Architecture at its fullest, allowing me to develop modular, robust and escalable websites with the confidence of having a solid base behind. Using WTA also allows my themes to be fully compatible with most, if not all, the plugins out in the market.

I am also a Progressive Enhancement maniac, so unobtrusive JavaScript and Performance matters to me.

  • The techie stuff:
  • Custom Theme Development
  • Custom Plugin Development
  • High OOP PHP knowledge, both oriented to WP and vanilla PHP7
  • High knowledge of WP architecture
  • Experience working with most of the popular plugins : ACF, WooComerce, Yoast SEO, Tribe Events and more
  • Experience with Gutenberg, React and Redux
  • Experience with WP Rest API
  • Ability to integrate external API services into your theme / plugin
  • Development with performance in mind
  • Ability to take advantage of server cache techniques to reduce the number of queries

Some projects I have worked on


Fully flexible website for a fintech company based in Barcelona, Spain. Flexible layouts were used to allow them to create a wide variety of landing pages. Kantox internal API was also integrated using a REST API wrapper that I developed using JS, PHP and the Curl library.

Aula de Fotografia Subterranea

Spanish website that I made time ago when I worked as a freelance in Spain. I took ownership of the whole process, from discovery and design to built and deployment. The result is a fully working Blog site which uses WordPress template architecture at it fullest.

WP Post Authors

WordPress plugin that I made by myself to avoid having to re-assign authors to posts after migrating high content sites. The plugin is simple: you choose which author's posts you want to migrate, and then you choose to whom you want to re-assign. With this plugin I put in practice a concept I love: 'Funcional Animation'.


Massive videogames streaming website made with WP which has a membership system to allows users to watch paid content. Payment systems were integrated into the website. The client also requested a custom funcionality to upload and manage monthly streaming schedule, which I developed creating a whole new section in the dashboard with PHP.


Although my main professional focus relies in WordPress and PHP, in recent years I have embraced that dark side of the web that some people call "JavaScript". Jokes aside, I started learning JS in deep due to its flexibility and dynamism when approaching development. I felt fascinated by fact that the same language allowed me to develop almost any piece of software, from very simple websites to complex single page apps and even videogames.

At the moment I am expanding my knowledge by learning in deep JS frameworks like React.js. At the same time, I am also experimeting with videogame development in the web, being Galbalith, a fully RPG made with JS ES5 working natively on the web, one of the most complex and ambitious projects I have ever worked on.

Some more techie stuff:

  • In-deep knowledge of the language: scopes, closure, 'this' mechanism, Objects Prototype Linkage, type conversion, etc
  • Ability to work with both Vanilla ES5 and ES6+
  • Experience with libraries like jQuery
  • Experience working with React and Redux

JS Projects


Galbalith is the name of a fully RPG game which will work natively on the web. It will translate the game mechanics and gameplay from old 90s classic RPGs like Final Fantasy and Chrono Trigger. Technically the code is written using OOP Vanilla ES5. Pixie.js is used as a base to load, draw and manipulate graphics on the screen.

RSP - Prototype

This is the prototype of a little interactive game where the player has to defeat three oponents in a row in a rock-paper-scissors game. The final version will be fully developed with Vanilla ES6 classes (current version uses ES5 object prototype linking approach) and will use simple machine learning techniques to increase the difficulty of some of the oponents.

HTML5 Platform Game

One of my first game development projects using JS. Following a course published by Mozilla I created a simple platform game which works natively in the web browser. It uses Phaser.js to handle all the game physics and graphics manipulation. This game can't be played on mobile as touch screen controls were never implemented on the demo version.

Tic Tac Toe Game

A simple tic tac toe game that I develop using React.js. The game has some unique features to enhance the UX, such us allowing the player to go back to previous game states, or seeing a full history of old previous plays. Using React, I could isolate each component based on their funcionality. Currently, the game is being rebuilt with a new interface and the posibility to play against the CPU.

Other Skills

  • High detail to UX and UI.
  • High detail when replicating a design using Front End technologies.
  • Agency experience. Ability to work in high pace enviroments with tight deadlines.
  • Experience with Google, Facebook, Twitter, Instagram and Linkedin APIs.
  • Experience using GIT.
  • DB systems and MySQL knowledge. Able to map custom databases and convert them into a fully working DB for WordPress.
  • System administration experience. Ability to do full site migrations.