David Marín

A set of websites based on WordPress and WooCommerce, including one main eCommerce site with millions of orders and thousands of active users. Working on this project for more than seven years, I've been the lead developer for these sites.

I started the project cleaning and optimizing lots of legacy code that made the page slow, setting the usage of good practices. We achieved the speed targets.

I also developed multiple custom features to comply with marketing team requirements and multiple patches and improvements for WordPress core and several existing WordPress and WooCommerce plugins.

I developed several custom reports, implemented using low-level complex SQL queries.

I implemented an automated test suite with Selenium to track the working conditions of the site.

I debugged and supported a variety of hosting problems, successfully identifying several bottlenecks in the code.

I led the effort to carry out the needed adaptations to migrate the sites from PHP 5 to PHP 7 and then to PHP 8.1

I adapted the whole set of customizations to use the new WooCommerce HPOS database schema (High-Performance Order Storage).

I successfully migrated the site among several hosting platforms with minimum downtime.

I developed the shipping subsystem for this marketplace site based on CraftCMS, developing a plugin to allow the calculation of shipping prices and estimated time lengths using the external Shippit API services.

I also developed the back end for vendors for this site so that they can keep track of orders and past orders. They can also manage the corresponding shipments, sending the corresponding e-mail messages to final customers.

The design and implementation of the website for this periodical bulletin, using WordPress, IssueM, and other plugins. Using a responsive theme, the site was designed from scratch using Twig and Timber, and a specific theme template was implemented for sending overviews of just-released issues using email marketing tools.

I developed a Linux audit and monitoring system for a startup based on a pre-loaded library and PAM module that captured all the executed commands and their generated output and sent them to an API for later consumption.

I developed a whole eCommerce website using WordPress and WooCommerce with other plugins.

I built a new theme translating Photoshop mockups into the corresponding HTML, CSS, and JavaScript routines.

A new report generation system for Canal de Isabel II, Madrid, Spain's main public water supplier.

Back end: C#, ASP.NET, MVC Framework, NHibernate, and Microsoft Excel.

Front end: Single-sage Application using React and Bootstrap.

I was the main designer and developer of this modular web system that provides all needed features for supporting infrastructure operation and exploitation: event and incident management, fleet management, stock control, preventive and corrective maintenance, and shift management and works management. Different modules can be installed based on the requirements of each project.

I acted as the main designer and developer of this web-based report system for SICE's ITS solution. This solution provides several reports related to traffic management that are shown on the web or can be exported to Excel or PDF formats.

A web page for an NGO using WordPress with several plugins and WooCommerce for the online shop.
To keep some information, I made adaptations and customizations of a purchased theme and several custom post types.

I was the project leader and main developer.

GnoMint is a tool for easily creating and managing certification authorities. It provides fancy visualization of all the information pertaining to a CA, such as x509 certificates, CSRs, and CRLs. GnoMint is currently capable of managing a CA that emits certificates that can authenticate people or machines in VPNs (IPSec or other protocols), secure HTTP communications with SSL/TLS, authenticate and cipher HTTP communications through Web-client certificates, and sign or crypt email messages. It's programmed in C using GTK+, SQLite, and GnuTLS libraries.

The project was created as the final-year project of my master's degree in computer science engineering.

A website based on WordPress software. The website was mainly based on pictures of designs made by the studio. The base template was totally transformed, so the main page showed a very different grid-based layout for the main page.

The design and full implementation of a calculation engine programmed in Java for DamData: Ofiteco's specialized dam auscultation SCADA. The formulas are expressed in a formula definition language that is defined formally through lexical and syntax grammar. These formulas are compiled into grammar trees through compiler classes generated using ANTLR. The formulas are invoked by the SCADA and allow different calculations using current and historical data.

In the context of the construction of Madrid Calle-30 tunnels (a 47 km urban tunnel network) and the development of its control system, I was responsible for analyzing, designing, and developing the ventilation algorithms for activating and controlling the different fans and ventilation-related equipment in the tunnels, following the guidelines marked by experts in the field.

I also worked on improving the scalability and robustness of SICE's RCUs (Linux-embedded systems based on x86 architecture) so that they could manage and control more than 9,000 analog and digital inputs and outputs.

The system allows employees to start different procedures (asking for vacation, notifying of changes in a family situation, taxes, etc.) that involve several steps of bureaucracy. In every step, the assigned group of people is notified about the pending actions, allowing them to interact with the application.

I used PHP and MySQL in the server and PDF and FDF for the forms.

Amidst the development of an institutional website for the different museums in the province of Huesca (Spain), I developed a routing engine for calculating optimal routes for visiting the different selected museums. Based on the traveler's algorithm, the different routes were pre-calculated to ensure a fast response to the user.