Francisco Gutiérrez Sarazá, Developer in Batumi, Adjara, Georgia

Francisco Gutiérrez Sarazá

Software Developer

Batumi, Adjara, Georgia
Toptal Member Since
February 7, 2020

Francisco started developing more than 20 years ago, working primarily as a full-stack developer. About five years back, he chose to focus on front-end development. He is a JavaScript evangelist comfortable with Node.js. Francisco shines in creating UX solutions and loves learning new technologies, expanding his capabilities, and sharing his knowledge and experience with colleagues.

Francisco is available for hire
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Colgate-Palmolive - Main
React, NX Monorepo, Mock Service Worker (MSW), Cypress, MUI (Material UI)...
React, Node.js, Progressive Web Applications (PWA), Mocha, Sinon.JS, Gherkin...
React, Redux, Cypress, Create React App, React Router, CSS3 Animation...


Batumi, Adjara, Georgia



Preferred Environment

Git, Node.js, NPM, Bash, Unix, Visual Studio Code (VS Code), Windows Subsystem for Linux (WSL)

The most amazing...

...thing I've done was to mentor developers to continue coding despite difficulties and to remain enthusiastic about what they can achieve.

Work Experience

2022 - 2023

Full-stack Developer

Colgate-Palmolive - Main
  • Built the entire front-end architecture from scratch using Nx, resulting in a robust and scalable TypeScript/React application with multiple libraries.
  • Created extensive documentation for the working environment and development process, facilitating smooth onboarding and collaboration among team members.
  • Developed a 3D interactive jaw map using Three.js, allowing for the seamless rendering of 3D images and enhancing the user experience.
  • Built a Node.js microservice using Puppeteer for PDF rendering, ensuring seamless integration between the front-end and back-end systems.
  • Utilized "Mock Service Worker" to emulate the back end, enabling independent front-end development and smooth integration with the back end, effectively preventing bottlenecks in the development process.
  • Automated generation of types, fetchers, and example data using the OpenAPI definition from Django, safeguarding against compile-time type errors in the front end when back-end changes occur.
Technologies: React, NX Monorepo, Mock Service Worker (MSW), Cypress, MUI (Material UI), Three.js, Puppeteer, Microservices, Okta, Gigya, OpenAPI, TypeScript, CSS3 Animation, JavaScript, HTML, Front-end, Front-end Architecture, Full-stack
2022 - 2022

Full-stack Technical Lead

  • Led a team to turn a legacy windows app into a PWA (after studying other solutions, such as React Native for Windows). The main target was to share a "Mural" with a big screen device (as Surface Hub mainly) without introducing sign-in data.
  • Developed the back end in Express.js for the custom endpoint. Also achieved with proper Gherkin tests.
  • Refactored the front end with POC and removed legacy libraries such as React Router/Redux, helping Mural to deliver more with less effort.
  • Developed the front-end unit (Mocha, Sinon.JS, and React Testing Library) and integration tests (Mocha, Sinon.JS, and Gherkin).
Technologies: React, Node.js, Progressive Web Applications (PWA), Mocha, Sinon.JS, Gherkin, React Native, Express.js, CSS3 Animation, JavaScript, HTML, Front-end, Front-end Architecture, Full-stack
2021 - 2022

Front-end Tech Lead

  • Shrank the JavaScript bundle from 10 MB to 5 MB using code-splitting, lazy loading, removing dead code, updating, and removing obsolete libraries.
  • Created integration tests from the ground (more than 15) using Mock Service Worker and Cypress. Included them in the CI using GitHub Actions.
  • Removed all the useless URL redirections and created descriptive and idempotent ones.
  • Eased multi-environment (Windows, Linux, and Mac) development for my workmates.
  • Implemented self-formatting Git hooks using Husky, Prettier, and ESLint. Also cleared 500 console errors/warnings in existing code, obfuscating the introduced errors.
  • Mentored back-end developers and junior coders to improve their skills in the front end in areas like modern JavaScript, Cypress test creations, and readable code.
  • Created a code style guide for the front-end development and the main documents in the repository to set up the environment, run all the scripts, and develop integration tests.
Technologies: React, Redux, Cypress, Create React App, React Router, CSS3 Animation, JavaScript, HTML, Front-end, Full-stack
2021 - 2021

Front-end Tech Lead

  • Developed the documentation site using Next.js, with support for markdown with Mermaid code and OpenAPI documentation supported with ReDoc.
  • Built a completely static site using Next.js with a static sitemap generator and WebP images stored in Cloudflare via Wrangler.
  • Delivered these two sites within a three-month timespan as the team was learning Next.js, TypeScript, Tailwind, and all the particular requirements from the company.
Technologies: Next.js, React, SQL Server Reporting Services (SSRS), Cloudflare, OpenAPI, CSS3 Animation, JavaScript, HTML, Front-end, Full-stack
2019 - 2021

Front-end Team Leader

Gaming Innovation Group
  • Refactored an existing casino in Preact to React and made a complete map of resources to make it easy to onboard their developers, improving the SEO.
  • Used Vue, Vuex, and web components to create state-of-the-art new brand casinos.
  • Refactored another online casino with Vue and web components.
Technologies: Web Components, Vuex, React, Vue, Preact, Pixel Perfect, CSS3 Animation, JavaScript, HTML, Front-end
2018 - 2019

Front-end Team Leader

William Hill
  • Promoted and created a monorepository toolchain using Lerna.
  • Developed performance tests for components using Puppeteer and headless Chrome.
  • Integrated a selector-sharing system for the entire app, that can be used by UIs and QAs for testing.
Technologies: Redux, Lerna, React, Storybook, Puppeteer, CSS3 Animation, JavaScript, HTML, Front-end
2017 - 2018

Senior Front-end Developer

Addison Global
  • Developed native apps in Android and iOS using React Native.
  • Shared my knowledge about good patterns using styled components.
  • Used Redux, sagas, the NativeBase library, and overall Lerna mono repository administration.
Technologies: iOS, Android, Styled-components, React Native, Storybook, CSS3 Animation, JavaScript, HTML, Front-end
2017 - 2017

Senior Front-end Developer

Rindus (Douglas SL)
  • Served as the front-end technical lead in Spain for Rindus and Douglas.
  • Created three practice communities to teach the benefits of Redux and sagas.
  • Refactored the front-end UI's old patterns related to CSS.
Technologies: Sass, Sagas, Redux, React, Pixel Perfect, CSS3 Animation, JavaScript, HTML, Front-end
2016 - 2017

Senior Front-end Lead

Ingenia SA (Swissquote)
  • Took charge of the front-end responsibilities turning a Flash/Flex application into a microservice HTML5 based one.
  • Mentored two junior front-end developers on React and TypeScript.
  • Developed a modular component system using (back then) new technologies like Webpack, PostCSS, TypeScript, React and Redux.
Technologies: Redux, PostCSS, BEM, React, TypeScript, CSS3 Animation, JavaScript, HTML, Front-end
2016 - 2016

Remote Senior Front-end Developer

  • Created a few components using the best patterns in CSS with BEM.
  • Implemented a ducks module pattern for Redux, storing the reducer aside with the actions.
  • Properly used sagas for asynchronous actions and to avoid rerendering.
Technologies: Sagas, Redux, JavaScript, React, CSS3 Animation, HTML, Front-end
2013 - 2016

Senior Full-stack Web Developer

CLC World Resorts & Hotels
  • Developed complete WordPress sites with custom themes/add-ons.
  • Transformed a top sales presentation tool from Flash to HTML5 using Angular, Reveal.js, and so on.
  • Built a few small landing pages using Laravel in PHP for mailing purposes.
Technologies: WordPress, CSS, PHP, HTML5, JavaScript, SQL, CSS3 Animation, Front-end
2011 - 2012

Full-stack Developer

Atlas Informática SL
  • Developed Atlas' complete sub-brand sites based on Joomla sites with custom templates and multiple languages: and
  • Managed and created a plugin to export to Excel catalogs on the main application (Magento).
  • Synced a new brand "Versus Gaming" catalog with an Amazon shop.
Technologies: Microsoft SQL Server, PHP, Magento, Joomla, SQL, CSS3 Animation, JavaScript, Front-end
2006 - 2011

IT and Full-stack Developer

Asociación de Editores Andaluces (AEA)
  • Converted a static single-page website into a multiple-language supported site,, using Joomla custom components.
  • Built the site and provided the full support for more than 70 editorials.
  • Installed new computers, printers, and a Linux operating system, saving the organization the cost of paying for licenses.
Technologies: Hardware, Joomla, PHP, SQL, CSS3 Animation, JavaScript, Front-end
2010 - 2010

Front-end UI Developer

  • Launched a new eBook shop for the most important phone provider in the country.
  • Created jQuery plugins to fit the requirements from the client (Ajax functions included).
  • Implemented CSS3 new properties used with media queries and HTML5 new tags and accessibility in the whole site.
Technologies: CSS3, HTML5, jQuery, CSS3 Animation, JavaScript, Front-end


The Bait Bot
Created this tool to use with my friend to make a podcast called Asynchronous Debates.

It registers the voice message duration and author (with alias) and generates different types of information.

• Duration script with a pie chart along with participation data.
• Script with every member intervention and a subtitle SRT generator.
• Ability to delete and reorder messages.

I also built a website in React to download all the media files in one zip (it is client-generated, so no processing is required for this). The bot uses Firebase functions and Firebase. I also wrote a Medium article about how to do this:

I wanted to create custom keyboards to delete the messages and use web assembly to generate a single file in the client.

My sandbox to test and master new libraries and create a list of videos from multiple services. The site has undergone several iterations and improvements.

1st version: jQuery and Laravel
2nd version: Laravel and Angular 1.5
3rd version: Angular 2.0
4th version: Angular 2.0 without a back end in React
5th version: React, Redux, and Sagas
6th version: No npm vanilla JavaScript with Lit web components and PWA

• Custom pub/sub store
• Custom router
• Service workers
• Cache to work offline
• IndexDB for local storage
• Serverless firebase functions
• Web components with LitElements

Cra JSON Sass Package
I created this small package to import JSON to be used into a Create React app application without any ejections. The main target was to use this for selectors so you can safely map them for QA, SCSS, and JavaScript components.

I developed this WordPress site with a custom template for SlingFast (a dirtbike company). I advised the company to sell their products on Amazon instead of a custom shop because it's difficult for a new brand to generate confidence.

From 2007 to 2016, I worked as a freelancer in conjunction with Juan Luis Molina (a designer) to make sites and videos. We developed state-of-the-art sites using eCommerce, Joomla, WordPress, PrestaShop, and so on while never using templates.



JavaScript, TypeScript, JavaScript 6, CSS, Sass, HTML5, HTML, PHP, Bash, CSS3, Gherkin, SQL, Python 3, Python


Tailwind CSS, Next.js, MUI (Material UI), Redux, React Native, AngularJS, Cypress, Vanilla JS, Express.js, Electron, Django


React, Node.js, Preact, Vue, jQuery, Vue 2, Vuex, OpenAPI, React Router, LitElement, Sinon.JS, Puppeteer, Three.js, Gigya


Unit Testing, Agile, Agile Software Development, Automated Testing, BEM, Microservices


Pixel Perfect, Front-end, Web Applications, Full-stack, Technical Leadership, Leadership, CSS3 Animation, Storybook, User Experience (UX), User Interface (UI), Mobile Apps, Cloud, Architecture, Software Design, Startups, Front-end Architecture, CI/CD Pipelines, OAuth, Single Sign-on (SSO), Sagas, Styled-components, Web Components, Hardware, Cloudflare, Telegram Bots, PWA, Progressive Web Applications (PWA), Windows Subsystem for Linux (WSL), APIs, NX Monorepo, Mock Service Worker (MSW), Okta, Amazon RDS


Git, PWABuilder, NPM, PostCSS, Lerna, Create React App, Mocha, Amazon CloudFront CDN


Firebase, WordPress, Joomla, Visual Studio Code (VS Code), Unix, Android, iOS, Magento, Google Cloud Platform (GCP), Amazon Web Services (AWS), Amazon EC2, AWS Elastic Beanstalk


MySQL, Microsoft SQL Server, SQL Server Reporting Services (SSRS), Google Cloud, Amazon S3 (AWS S3)


2014 - 2016

Higher National Diploma (HND) in Web App Development

IES Aguadulce - Almería, Spain

2004 - 2006

Higher National Diploma (HND) in Media Production

IES Angel de Saavedra - Córdoba, Spain



Python TOTAL - Programador Avanzado en 16 días (Advanced Programmer in 16 Days)



AWS Curso Básico para desarrolladores web. (AWS Basic Course for Web Developers)