Tomas Casas, Developer in Córdoba, Cordoba, Argentina
Tomas is available for hire
Hire Tomas

Tomas Casas

Verified Expert  in Engineering

PHP Developer

Córdoba, Cordoba, Argentina
Toptal Member Since
December 20, 2013

Tomas is a software engineer with a passion for problem-solving. He's had the opportunity to work with OOO and functional paradigms. For the last 15 years, Tomas has been doing web applications using PHP and JavaScript. He then focused on JavaScript for SPA and moving and redesigning a React SPA using ClojureScript. He has been a contractor for US-based companies, corporations, and startups for over 10 years.


Create React App, Webpack, Next.js, Node.js, Material UI, Docker, Kubernetes...
CSS3, HTML5, JavaScript, Reagent, Material UI, ClojureScript, React, Redux...
Walt Disney Parks and Resorts Online
HTML5, CSS3, JavaScript, PHP




Preferred Environment

GitHub, Visual Studio Code (VS Code), React, Material UI, Create React App, Webpack, Node.js, Microservices, Docker, Kubernetes

The most amazing...

...things I've developed are a SQL tokenizer to filter and sort in-memory objects and a pop-under by injecting code to a new about blank tab.

Work Experience

Senior Software Engineer

2020 - 2022
  • Collaborated with the front-end team in creating and supporting a components' library, CRA, and Next.js apps. Deployed CRA apps as static assets served from GCP storage. The Next.js app was deployed to Heroku.
  • Transitioned all FE repositories into a single mono repository for easier code reuse.
  • Designed and crafted the billing microservice for Shopify's usage-based charges using routers, handlers, and DAOs.
  • Learned a lot about the MS ecosystem with Docker images running in Kubernetes containers in GCP. Collaborated with the front-end team in creating and supporting components' library and CRA and NextJS apps.
Technologies: Create React App, Webpack, Next.js, Node.js, Material UI, Docker, Kubernetes, Google Kubernetes Engine (GKE), Docker Swarm, Docker Hub, Redis, MongoDB, PostgreSQL, Microservices, WebSockets, CSS3, HTML5, GitHub, Design Patterns, Business Requirements, Amazon Web Services (AWS), CircleCI

UI/UX Developer

2014 - 2020
  • Migrated the leading site from React and Redux to CLJS using Reagent and reframed together with Material UI.
  • Collaborated transition from Backbone to Redux and React with new features. The process started by moving away from Grunt to Webpack to deal with packaging the app and rendering HTML templates. That helped build Node.js and Express.js skills.
  • Ported a hotel meta-search site from a proprietary framework to Backbone with responsive design and helped build a proprietary state controller stack to deal with app state and browser history.
  • Supported a Google Chrome price check extension checker, Scout.
  • Assisted unit and integration tests using Mocha and Cypress.
  • Held up a component to trigger pop-unders and tab-switches on partner sites.
Technologies: CSS3, HTML5, JavaScript, Reagent, Material UI, ClojureScript, React, Redux, Immutable.js

Team Leader, Web Developer

2012 - 2013
Walt Disney Parks and Resorts Online
  • Coordinated tasks for a group of five PHP and four QA developers and supported the overall interaction of four engineers with the client.
  • Received client specifications and discussed them with client product owners and business analysts.
  • Worked on app performance using REST request parallelization and resiliency to handle the event of service degradation.
  • Worked on a calendar jQuery plugin.
  • Created other frameworks and libraries, including the Zend Framework 1.x, Guzzle, jQuery, and Mustache.
Technologies: HTML5, CSS3, JavaScript, PHP

Partner Contractor

2011 - 2011
Threevoice – FlamingoTV
  • Developed web UI and core components to enable the company to provide prepaid and postpaid VoIP services.
  • Created a client dashboard on top of Zend 1.x and Doctrine2.
  • Managed OpenSips and the Asterisk configuration through Web UI.
  • Built Java handlers implementing a radius dictionary for billing (created by another colleague).
  • Mirrored two stand-alone servers with one acting as master and the other as slave. Implemented them to switch roles in the case of unavailability events.
Technologies: PGP, Sippy Softswitch, RADIUS, OpenSIPs, Asterisk, Unix, PHP 5


2010 - 2011
The World Bank
  • Helped to adapt the wage model for the Peruvian government.
  • Helped to adapt the wage model for Antigua and Barbuda's government.
Technologies: Excel VBA, Microsoft Excel

Web Developer

2010 - 2011
  • Created a web UI to manage email marketing campaigns.
  • Created a "threaded" console daemon using a Unix fork to handle email processing (client use of PHP required).
Technologies: Unix, PHP 5

Web Developer

2010 - 2011
  • Created an application responsible for mapping real estate attributes from a client app using ZonaProp web services DTD.
Technologies: PHP 5

Web Developer, Technology Integrator, Partner

2009 - 2010
  • Created a solid state PBX built on top of the NanoBSD OS with MySQL for data and LightTPD as web server.
  • Developed the PHP 5.2 user interface to manage users, groups, IVRs, and terminations.
  • Added a remote deployment of new releases and license management.
  • Created a C++ extension for SEMS to enable prepaid calling cards.
Technologies: C++, Asterisk, lighttpd, MySQL, PHP 5, FreeBSD

Contractor, Business Analyst, Developer

2006 - 2010
Lockheed Martin Aircraft Argentina SA
  • Resumed efforts pursuing short-term manufacturing plans based on resource availability.
  • Created proofs of concept with ASP.NET and C# to leverage product configuration and midterm planning.
Technologies: ADABAS, Visual Basic 6 (VB6), C#, ASP.NET


2008 - 2008
The World Bank
  • Helped in the adaptation of the wage model for Paraguay's Government.
Technologies: Excel VBA, Microsoft Excel

Business Analyst

2005 - 2006
Vates SA
  • Worked to mock a prospective new product for the company.
  • Prepared proposals for the public sector, including local and nonlocal biddings.
  • Prepared use case analysis for a Transantiago (Chile) project working for Siemens Itron. Helped with Java business rules coding.
Technologies: CSS, HTML, JavaScript, Java, Use Cases, Rational Unified Process (RUP)

Junior Professional Associate

2002 - 2004
The World Bank
  • Handled IT support for LCSHD.
  • Collaborated with the “ITC for State Strengthening” terms of reference and project structure.
  • Provided statistical analysis infrastructure through terminal services.
Technologies: Terminal Servers, Windows Server, Windows

Business Analyst, Systems Analyst

2002 - 2002
Harriague y Asociados
  • Helped with manufacturing system analysis and design.
Technologies: Use Cases, UML, Rational Unified Process (RUP)

Contractor, PM, Business Analyst, Developer

2000 - 2002
Lockheed Martin Argentina SA
  • Prepared and won a bidding offer for a manufacturing system.
  • Negotiated requirements and project boundaries and integration to existing apps with client.
  • Analyzed and developed with a team of two other developers to create a platform to handle product configuration and an MRP level 2.
Technologies: ADABAS, Visual Basic 6 (VB6)


1998 - 2002
  • Built several projects related to product configuration and BOM.
  • Created a distance learning platform proof of concept for my university.
  • Developed a site for client invoice orders (Richetta SA - Sonepar Distribution).
Technologies: IIS, Microsoft SQL Server, IRC, Microsoft Access, Visual Basic 6 (VB6)


Help building a SPA for hotel metasearch. Started as a full in-house dev in ES5 and then evolved to be Backbone based, then React/Redux, to now be in the process of becoming CLJS (Reagent and re-frame) as the BE is CLJ.

Tech stack: CLJS, Reagent, Reframe, React, Redux, Clojure, Datomic

Walt Disney Parks and Resorts Online
A WDPRO (Disney World and Disneyland) UX site built using PHP, PHPUnit, Zend Framework 1.x, jQuery, HTML5, CSS3, Java (Selenium functional tests), and a RESTFul service layer. I worked as technical leader and web developer. This site handles park schedules, park tickets, resort booking, and personal itinerary and plans.

Flamingo VoIP Telephony Platform

This is a private site for FlamingoTV created using PHP 5.3, Unix, Asterisk, OpenSips, Radius, Sippy, Java, PGP. It features a full VoIP telephony platform integrated with two main custom developments, account management and a dashboard of calls and voicemails handled in a PHP web app, handling for prepaid card batch generation, media service usage, and CDR batch generation. I implemented accounting using a Java Radius client on the B2B (developed by another engineer from the team).

Bandin and Alfa Real State Franchise Property Ads

A private project I created as part of Modelos Digitales online services portfolio. It includes batch process Bandin and Alfa XML assets and pubishes them into the web service API ( The web UI is built to handle all franchise attributes and maps them into ZonaProp valid attributes and values. It also features a nice web UI, single or bulk publishing, and un-publishing as well. Email Marketing Campaigns

A private application that I created using PHP 5.3, Doctrine 2, Zend Framework 1.x, MySQL DB, and FreeBSD deploy ambient. It includes a batch processing daemon programmed in PHP and implemented using Unix fork. The web UI enabled clients to create their own campaigns. Filters were created based on a command chain using fall-through logic to to avoid saturation of email boxes.

Siemens Itron - Transantiago
I was a business analyst for a transactional switch implementing ISO 8583 protocol to authorize pre-paid cards for metro or bus transportation systems. I also collaborated as a Java developer on business logic implementation.

SIP/IPS - Integrated Production System

A Win32 App built with VB6 and an Adabas D database for persistence. The data was managed with AutoBASE. The platform was refactored and upgraded to support business logic on top of generic configurable forms. I was PM, business analyst, and VB6 developer, and managed product configuration and manufacturing planning from the BOM and based on resource availability. I also managed the inventory with traceability. After a few years, I added extended functionality for short-term production programming as well as a subset of features on ASP.NET with C# for a prospective new intranet app.
2005 - 2006

Master's Degree in Supply Chain Management and Technology

Universitat Ramon Lull - La Salle - Barcelona, Spain

1994 - 2000

Systems Engineer Degree in Systems Engineering

Instituto Universitario Aeronautico - Cordoba, Argentina

1992 - 1993

Coursework in Electronics Engineering

Universidad Nacional de Cordoba - Cordoba, Argentina


Doctrine 2, React, React Redux, Preact, Backbone.js, Underscore.js, jQuery, Sinon.JS, Chai, REST APIs, RADIUS, Node.js, jQuery UI, SyncJS, Mustache, Immutable.js


Microsoft Access, Adobe Photoshop, Apache, GitHub Pages, Eclipse IDE, Git, Perforce, MySQL Workbench, Asterisk, Atom, Reagent, JavaScript Debugging, WebdriverIO, Microsoft Excel, GitHub, Adobe Illustrator, Apache Tomcat, Mocha, Mercurial, Apache Ant, CorelDRAW, CVS, IBM Rational Rose, Inkscape, lighttpd, Subversion (SVN), Sublime Text 2, MongoDB Atlas, Create React App, Webpack, Google Kubernetes Engine (GKE), Docker Swarm, Docker Hub, CircleCI


Redux, Zend Framework, Rational Unified Process (RUP), NHibernate, Hibernate, Compass, ClojureScript, Cypress, OpenSIPs, Symfony 2, Bootstrap, Guzzle, CodeIgniter, ASP.NET, Slim, Yii, Material UI, Re-frame, Next.js


Visual Basic 6 (VB6), SQL, JavaScript, VB.NET, JavaScript 6, JavaScript 5, PHP 5, Visual FoxPro, Visual Basic for Applications (VBA), HTML5, CSS, HTML, PHP, CSS3, Excel VBA, UML, C#, JADE, Java, BASIC, C++, Pascal, Sass


Object-oriented Programming (OOP), RESTful Development, Agile Software Development, Prototype-based OOP, Unit Testing, REST, Procedural Programming, Functional Programming, Continuous Integration (CI), OLAP, Scrum, Behavior-driven Development (BDD), Dependency Injection, Inversion of Control, Microservices, Design Patterns


MySQL, Microsoft SQL Server, ADABAS, SQLite, PostgreSQL, Redis, MongoDB


NetBeans, Windows, Unix, Windows Server, MacOS, Visual Studio Code (VS Code), Ubuntu, iOS, FreeBSD, Oracle, Docker, Kubernetes, Amazon Web Services (AWS)


Web Development, Enterprise Architecture, Integration Testing, Front-end Development, Use Cases, Terminal Servers, Sippy Softswitch, PGP, IRC, IIS, Prototyping, VoIP, Unix Shell Scripting, WebSockets, Business Requirements, Systems Engineering

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.


Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring