Guilherme is available for hire

Guilherme Giannoulakis

Verified Expert in Engineering

Full-stack Developer

Chiang Mai, Thailand

Toptal member since June 18, 2021

Expertise

Front-end Full-stack CMS Web Scraping Data Scraping Serverless JavaScript HTML5 CSS PHP jQuery MySQL Laravel Vue Microservices Tech Freelancing

Bio

Guilherme is a full-stack developer specializing in optimized interfaces. He has worked on over 200 websites, eCommerce solutions, and web applications. He has guided and developed solutions for startups, from idea to execution, created a custom CMS for a private university with multiple access levels and dynamic features, and developed a subscription-based training platform where hundreds of users seamlessly migrated from the old platform, reducing transaction fees by 50%.

Portfolio

Xendit Incorporated

MongoDB, PostgreSQL, Node.js, TypeScript, APIs, React, Microservices...

Self-employed

React, JavaScript, Vue, Laravel, Full-stack, Databases, Linux, Git, Vercel...

Bravo Interativa

HTML5, CSS, JavaScript, Vue, Content Management Systems (CMS), WordPress...

Experience

Front-end - 14 years JavaScript - 14 years CSS - 13 years Content Management Systems (CMS) - 10 years Node.js - 4 years Express.js - 3 years React - 3 years Next.js - 2 years

Availability

Part-time

Preferred Environment

Visual Studio Code (VS Code), Front-end, APIs, Content Management Systems (CMS), Automation

The most amazing...

...tool I've developed was a website builder for marketing agencies, making them more efficient and increasing revenue by bringing in more customers.

Work Experience

Senior Software Engineer

2021 - PRESENT

Xendit Incorporated

Automated manual processes by researching, planning, proposing, and implementing solutions for a payment infrastructure platform.
Integrated different services and created dashboards, allowing internal teams more autonomy and productivity.
Helped close gaps in revenue by investigating different scenarios across multiple products and business logic.

Technologies: MongoDB, PostgreSQL, Node.js, TypeScript, APIs, React, Microservices, User Interface (UI), Datadog, Databricks, Scrum, Unit Testing, Automation

IT Conusltant

2016 - 2021

Self-employed

Developed process automation with bots and API integrations, reducing the friction for new customers.
Optimized websites for performance and SEO, using technologies such as static site generation and edge caching.
Guided and developed solutions for startups, from idea to execution.

Technologies: React, JavaScript, Vue, Laravel, Full-stack, Databases, Linux, Git, Vercel, Amazon Web Services (AWS), Systems Analysis, IT Project Management, Node.js, HTML5, CSS, Content Management Systems (CMS), WordPress, PHP, CMS, Front-end, Serverless, Express.js, Redis, Cypress, React Native, Next.js, jQuery, Puppeteer, MySQL, Firebase, APIs, Payment Gateways, Automation, TypeScript, Microservices, Web Scraping, Scraping, Docker, ECMAScript (ES6), GitHub, Python, HTML, User Interface (UI), Tailwind CSS, Data Scraping, WebSockets, AWS Lambda

CTO

2012 - 2016

Bravo Interativa

Developed custom software to support client acquisition and content management.
Developed hundreds of websites, coding detailed designs to responsive websites.
Started this company with a partner, surmounting many challenges as a business, dealing with a variety of clients and requests.

Technologies: HTML5, CSS, JavaScript, Vue, Content Management Systems (CMS), WordPress, Laravel, PHP, IT Project Management, Linux, Git, Systems Analysis, Full-stack, Databases, CodeIgniter, CMS, Front-end, jQuery, MySQL, APIs, Payment Gateways, Automation, GitHub, eCommerce, HTML, User Interface (UI)

Web Developer

2011 - 2012

Falara Gestão de Marcas

Worked closely with designers to create great front-end experiences for marketing campaigns.
Improved the team's web capacity, providing in-house solutions for clients.
Developed a 3D product personalization tool with Blender and Python scripts.

Technologies: Content Management Systems (CMS), JavaScript, HTML5, CSS, PHP, Python, ECMAScript (ES6), eCommerce, APIs, MySQL, jQuery, PostgreSQL, Front-end, CMS, CodeIgniter, Full-stack, Systems Analysis, Linux, HTML

Marketing Assistant

2007 - 2011

Univates

Developed a custom CMS solution for the main university website, with multiple access levels and dynamic features. This solution is still currently being used (2021).
Developed several solutions for internal needs, including integration with the main academic software.
Collaborated with end users, understanding their needs and providing solutions.

Technologies: PHP, CodeIgniter, CMS, Front-end, PostgreSQL, Linux, Systems Analysis, JavaScript, Full-stack, Databases, HTML5, CSS, Content Management Systems (CMS), WordPress, jQuery, MySQL, APIs, HTML

Experience

Theme Deploy

http://www.themedeploy.com

A website builder for marketing agencies. It was created to be user-friendly yet flexible. I planned the solution from scratch, then developed and published it. To improve flexibility, I developed a custom micro-front-end architecture, allowing the source code of any block to be edited or created. A custom build process was developed to generate the final code (HTML, CSS, JavaScript) with optimized images. Serverless and edge caching were incorporated into this project to allow scaling.

Estética Experts

https://www.esteticaexperts.com.br/

A subscription-based training platform for healthcare professionals. I planned and developed a new member area, offering clients a better user experience. Hundreds of users were seamlessly migrated from the old platform. I integrated it with the new payment gateway, reducing the transaction fees by 50%.

Usthemp

https://www.usthemp.com/

A personalized shoes brand where every product is unique. I developed the entire eCommerce solution, including product personalization and previews, a customized checkout, integration with payment gateways, delivery companies, invoicing, and marketplaces, and an ERP with product ID management, tracking the production process.

Univates CMS

https://www.univates.br/

Univates is a university in the south of Brazil that has graduated over 25,000 students since 1969. I joined the marketing team and created a custom CMS platform for web campaigns, including the main website. It brought several benefits for the team and the institution, such as the flexibility to create personalized designs, faster page loads, unification of different CMS solutions across websites, autonomy for other sectors to keep their content updated on the web, and easier integration with academic and other third-party software.

Education

2006 - 2013

Bachelor's Degree in Information Systems

University of Taquari Valley (Univates) - Lajeado, Rio Grande do Sul, Brazil

Skills

Libraries/APIs

Node.js, React, Vue, jQuery, Puppeteer

Tools

Git, GitHub

Languages

JavaScript, HTML5, CSS, PHP, HTML, ECMAScript (ES6), TypeScript, Python

Frameworks

Laravel, Express.js, Next.js, Tailwind CSS, CodeIgniter, Cypress, React Native

Paradigms

Microservices, Automation, Unit Testing, Scrum

Storage

MySQL, Databases, PostgreSQL, MongoDB, Redis, Datadog

Platforms

Linux, Vercel, WordPress, AWS Lambda, Amazon Web Services (AWS), Firebase, Docker, Databricks

Other

Systems Analysis, Full-stack, Content Management Systems (CMS), CMS, Front-end, Serverless, Web Scraping, Scraping, User Interface (UI), Data Scraping, Payment Gateways, WebSockets, IT Project Management, APIs, eCommerce

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