Marcelo Mazza, Developer in Buenos Aires, Argentina
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Marcelo Mazza

Verified Expert  in Engineering

UX Designer and Developer

Buenos Aires, Argentina
Toptal Member Since
April 18, 2015

Marcelo has been working for more than 14 years in top Internet companies, from large eCommerce sites, startups, and unicorns, as a user experience (UX) designer, developer, and team manager. He has solid knowledge of conversion rate optimization, mobile, UX, usability, design, front-end development, and WordPress, in addition to excellent interpersonal skills. Marcelo has proven experience in project management, strong organizational skills, and business knowledge.

A/B Testing, WordPress, Figma, Sketch, Git, HTML, CSS, Sass, JavaScript, GitHub... (via Toptal)
Git, CoffeeScript, Grunt, Less, Sass, HTML, Ruby on Rails (RoR), AngularJS...
UpgradedPoints (via Toptal)
Git, jQuery, Grunt, Sass, HTML, PHP, WordPress, HTML5, User Experience (UX)...




Preferred Environment

Chrome, Git, Terminal, Sublime Text, UI Design, Figma, Sketch

The most amazing...

...thing I've designed is the first version of a mobile app for the #1 eCommerce travel website of Latin America, with millions of customers.

Work Experience

A/B Testing, Business, CRO, Dev, and UX Consultant (via Toptal)

2018 - 2024
  • Joined the business. When I started, Alan was using HubSpot and Volusion. He was afraid of changes. After time and confidence, we moved the whole site to WordPress; this was a great move that allowed the site to scale better and assured a future platform for the business.
  • Created, along with the team, a great 3D widget in Three.js that still lives on
  • Switched—when the client needed—to a project manager position to allow him to work alongside the team and make it more productive.
Technologies: A/B Testing, WordPress, Figma, Sketch, Git, HTML, CSS, Sass, JavaScript, GitHub, Trello, Sublime Text, Terminal, WooCommerce, WP Engine, User Experience (UX), Web UI Design, Conversion Rate Optimization (CRO), Usability, Responsive Web Design (RWD)

Head of UX and Web Design, Developer

2015 - 2021 (via Toptal)
  • Defined a visual identity and brought a cohesive experience between the different apps.
  • Organized a spaghetti-style SASS and LESS codebase, defining structure and applying BEM principles.
  • Gathered data and brainstormed ideas for new developments and features.
  • Collaborated with the developers providing design support and CSS mentorship.
  • Worked alongside the CEO and CTO in the development of new features and definitions of the roadmap.
Technologies: Git, CoffeeScript, Grunt, Less, Sass, HTML, Ruby on Rails (RoR), AngularJS, Bootstrap, HTML5, JavaScript, User Experience (UX), UI Design, Front-end, Hubot, Responsive, Back-end, Usability, Responsive Web Design (RWD)

WordPress UX and CRO Designer/Developer

2015 - 2021
UpgradedPoints (via Toptal)
  • Created a new platform for a travel rewards site, starting with wireframes and design and moving on to WordPress implementation.
  • Set up a staging server with WPEngine and deployed the structure with Git.
  • Created a specific theme and plugin for the site, including different custom post types for the content, with different taxonomies and metaboxes.
  • Created specific WordPress plugins for the site, for custom functions.
Technologies: Git, jQuery, Grunt, Sass, HTML, PHP, WordPress, HTML5, User Experience (UX), UI Design, Front-end, JavaScript, MySQL, FTP, Responsive, Back-end, Usability, Responsive Web Design (RWD)

UX/CRO Designer and Developer | Mobile Team Lead

2013 - 2015
  • Designed, researched, and conducted A/B testing of new features.
  • Designed for mobile web and optimized features for EMK and PPC campaigns.
  • Created wireframes, conducted A/B testing, designed web features, and developed front-ends.
  • Analyzed data and came up with creative solutions.
  • Gathered business metrics and defined the impact of improvements.
Technologies: Git, Sketch 3, jQuery, CSS, HTML, User Experience (UX), UI Design, Front-end, Responsive, Usability, Responsive Web Design (RWD)

User Experience Manager

2011 - 2014
  • Set up a large team of 20+ interdisciplinary members with a diverse professional profile: Graphic and web design, usability, psychology, web development, systems engineering, and marketing and advertising.
  • Planned and designed usability testing and front-end development of every feature of
  • Designed interactions for all the mobile apps of (iPad, iPhone, Android, Windows Phone, Blackberry, etc).
  • Encouraged daily interactions between designers and developers to build a final product of quality and excellence.
  • Answered to and consulted with more than 20 internal clients, including the CEO, product owners, functional analysts, back-end developers, and customer service representatives.
  • Gathered functional and business requirements and converted them into interaction models.
  • Guarded the consistency and visual style of
  • Worked directly with front-end developers to assure the quality of the HTML and CSS of the site.
Technologies: Adobe Photoshop, Git, Sass, CSS, HTML, Fireworks, User Experience (UX), UI Design, Responsive, Usability, Responsive Web Design (RWD)

UX/Web Designer and Front-end Developer

2010 - 2011
  • Led the design and handled maintenance of the site.
  • Generated designs for new products along with stakeholders (PMs and C-team).
  • Redesigned existing sections of the website and brought consistency and a visual language.
  • Hand-coded CSS and HTML (standards era). At that time, the team still used Dreamweaver.
  • Introduced jQuery to the development team, and we implemented the company's first front-end development library of that type.
Technologies: Subversion (SVN), Fireworks, FreeMarker, jQuery, CSS, HTML, UI Design, Front-end

Lead Interaction Designer

2010 - 2011
  • Unified the look and feel of all the different existent products (Hotels, Flights, Travel Packages, Car Rental).
  • Defined the aesthetics and a visual identity for the website.
  • Designed the first versions of the mobile apps of the company.
  • Interacted with all the internal clients to get them to agree on a common design ground.
  • Introduced new technologies, workflows, and methodologies. Was ordered to create the UX team.
Technologies: Adobe Photoshop, Git, Sass, CSS, HTML, Fireworks, UI Design, Responsive

Web Marketing Designer

2008 - 2010
  • Designed and coded the marketing department's HTML newsletters.
  • Designed and coded landing pages focused on conversion rates for different marketing campaigns.
  • Animated banners and designed graphics for the website using Macromedia Flash.
Technologies: Subversion (SVN), CSS, HTML, Adobe Photoshop, Fireworks, UI Design

Contributor of WordPress 4.2 "Powell"
I contributed to the team of "Press This," a feature that was revamped for WordPress 4.2, by chatting, designing, and collaborating with the features.

I hope to do more open source work in the future. Dashboard Redesign

Akimbo Financial is an Austin, Texas-based startup is an Austin, Texas-based startup. First, responsive web design techniques were applied to the registration process and then to the overhaul of the dashboard. Then, it was integrated with the Zend framework, and SASS was used for the stylesheets and implementation of icon fonts.

Front-end Developer, Akimbo Financial, Inc.
Akimbo Financial is an Austin, Texas-based startup. I applied responsive web design techniques to the registration process first and then to the overhaul of the dashboard. For the Integration with the Zend framework, I used SASS for the stylesheets and implemented icon fonts.


jQuery, Modernizr, jQuery UI


Sublime Text 3, Adobe Photoshop, Adobe Illustrator, Git, Fireworks, Adobe Fireworks, Sketch, Sublime Text, Terminal, Sketch 3, FreeMarker, Subversion (SVN), Grunt, Figma, GitHub, Trello


Bootstrap, Bootstrap 3, ZURB Foundation, Chrome, AngularJS, Ruby on Rails (RoR)


UI Design, Responsive, Responsive Web Design (RWD), Agile Software Development, BEM, SMACSS, Conversion Rate Optimization (CRO), Search Engine Optimization (SEO), Web UI Design


Sass, JavaScript, CSS, HTML, SCSS, HTML5, CSS3, Less, CoffeeScript, PHP


WordPress, WooCommerce


MySQL, WP Engine


Front-end, User Experience (UX), Usability, Performance Optimization, eCommerce, Hubot, FTP, Back-end, A/B Testing

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