Matthias Leu, Developer in Chiang Mai, Thailand
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Matthias Leu

Verified Expert  in Engineering

Shopify Developer

Chiang Mai, Thailand
Toptal Member Since
April 30, 2024

Matthias has an impressive 15-year track record of creating and maintaining successful eCommerce systems. He has expertly built numerous Shopify apps, Vue integrations to Shopify, UI functionalities, and Shopify integrations to 3rd-party providers. Matthias can provide complex front-end solutions and outstanding back-end experiences, which makes him an ideal candidate for full-stack roles.


Blazar Capital
Shopify Plus, Shopify API, Shopify Theme, Vue, Tailwind CSS, REST, GraphQL...
Croox Cross Over Experts
Nuxt.js, Vue, HTML5, React, CSS5, SQL, JavaScript, WordPress
Dinnagan Garden Co. Ltd.
JavaScript, HTML5, CSS5, SQL, Vue, Go




Preferred Environment

Shopify Plus, Shopify API, Shopify Theme, Nuxt.js, Visual Studio Code (VS Code), NPM, Vite, MongoDB, Vue

The most amazing...

...solution I've created is an advanced Shopify-based UI for taking scalp photos and analyzing the resulting data with an AI model hosted on AWS.

Work Experience

Senior Shopify Engineer

2020 - PRESENT
Blazar Capital
  • Developed over 50 Shopify Theme sections using Liquid, HTML5, Vue, and Tailwind CSS, enabling customers to swiftly integrate new features and Figma-based designs into five different Shopify shops.
  • Introduced a Vite-based deployment pipeline using Shopify CLI, enabling project bundling and deployment across multiple country shops in seconds.
  • Built a Shopify app proxy that allows front-end calls to cryptographically secured API integrations with five different 3rd-party services, boosting customers' CRM capabilities by providing real-time data to their systems.
  • Created a Vue-based customer back end to administer subscriptions and orders, replacing the default Shopify account area and improving customer satisfaction by reducing customer service workload.
  • Made a Shopify-integrated app to collect photos of hair characteristics and send them to an AWS-hosted AI model to determine health issues via an AI-based model.
Technologies: Shopify Plus, Shopify API, Shopify Theme, Vue, Tailwind CSS, REST, GraphQL, JavaScript, TypeScript, Liquid, HTML5

Senior Developer

2020 - 2023
Croox Cross Over Experts
  • Created a data analysis back end that displays accumulated healthcare data for a mobile-based health data tracking app that allows hospitals to track the well-being of their customers.
  • Developed a React-based WordPress plugin for managing room rental services, enabling healthcare providers to rent out unused office space.
  • Implemented API integrations for accounting software APIs, eliminating data entry tasks for the customer.
Technologies: Nuxt.js, Vue, HTML5, React, CSS5, SQL, JavaScript, WordPress

Full-stack Developer

2018 - 2020
Dinnagan Garden Co. Ltd.
  • Planned a Vue and Go-based farm management system to manage resources and provide analytical reporting for an organic farm in Thailand, facilitating data acquisition and farm management.
  • Created the back end for the system on Go and the front end on Vue.
  • Worked with the users to improve UI functionality and ease of use.
Technologies: JavaScript, HTML5, CSS5, SQL, Vue, Go

Senior Web Developer

2016 - 2017
BlackSnow ApS
  • Overhauled the existing online shop and implemented a complete redesign.
  • Implemented a custom check-out system, increasing customer conversion significantly.
  • Handled all online shop aspects during its growth phase until the company was sold.
Technologies: CSS5, HTML5, PrestaShop, SQL, JavaScript

Development Manager

2013 - 2015
  • Built a specific department offering web programming services to hosting customers to increase customer retention.
  • Worked on more than 40 homepage use cases to implement customer websites.
  • Grew the department to profitability within one year and a half.
Technologies: SQL, HTML5, CSS5

Web Developer

2011 - 2013
Media-Concept Bürobedarf
  • Set up two online shops based on the PrestaShop framework.
  • Implemented SEO strategies to increase visitor traffic.
  • Built API integrations to the central .NET-based API, ensuring fault-free real-time order data synchronization.
Technologies: SQL, MySQL, SEO Tools, HTML5, PrestaShop, JavaScript, Search Engine Optimization (SEO), .NET

Senior Web Developer

2007 - 2010
  • Set up, designed, and maintained the company's web presence and online shop for industrial computer hardware.
  • Oversaw the entire online sales channel, supervising all related processes and implementations.
  • Created APIs with Taiwanese manufacturers, collaborating with their IT side to automatically feed product information to the website.
Technologies: HTML, CSS5, JavaScript

Software Developer

2006 - 2007
  • Handled the central data-entry business case implementation.
  • Collaborated with the testing team to secure process integrity in a team of over 30 developers.
  • Acted as the point of contact for the customer testing team, creating valuable solutions and improvements based on their input.
Technologies: Java

AI Hair Loss Detection Tool
I created a Shopify-embedded UI tool for visitors to upload photos of their hair and scalp. This solution analyzes the images through an AWS-based AI model that determines hair issues that can be treated with company products. This tool is a Vue-based UI with AWS API integration that sends photos to the AI model.

Shopify Customer Portal to Administrate Subscriptions and Orders
This project involved creating a Vue-based single-page application to replace the standard Shopify customer back end. It required REST and GraphQL API integration to Shopify core and recharge subscription services. The new implementation allows customers to add, swap, reschedule, change, cancel, remove, and skip products and subscriptions.

API Proxy App for 3rd-party API Integrations

This project involved developing a Shopify app that offers API endpoints through an app proxy, allowing front ends to use this API to securely communicate with 3rd-party services, including Klaviyo, AWS, ReferralCandy, and Shopify API.

Shopify Quiz App
A tool that integrates SurveyJS into a Shopify app wrapper, offering a Shopify quiz generator. The solution was implemented as a Vue-based front end with metadata created by the survey back end. In addition, data is stored leveraging MongoDB.

Deployment Pipeline
I created a Vite-based Shopify theme deployment setup, enabling project bundling and deployment in seconds over multiple different country shops. This resulted in a distinguished setup with dynamic imports to reduce JavaScript page load and individual script loads.

Medical Customer Data Analysis Dashboard

I developed a Nuxt-based back end to allow administrators to check statistical user mobile app submitted data on different graphical levels.
Graph representations leveraged Chart.js and included complex data range zooming. In addition, data storage was implemented through a Parse back-end server.
2004 - 2004

Diploma in Computer Science

National University of Singapore - Singapore

1998 - 2004

Master's Degree in Computer Science

Technical University of Munich - Munich, Germany


Liquid, Vue, REST APIs, Shopify API, Node.js, React, Chart.js, SurveyJS


Shopify Plus, PrestaShop, AWS IAM, NPM


Tailwind CSS, Nuxt.js, Express.js, .NET


JavaScript, HTML5, HTML, Shopify Liquid, CSS, TypeScript, Java, SQL, GraphQL, Go


REST, Search Engine Optimization (SEO)


Shopify, Parse Server, Visual Studio Code (VS Code), WordPress, Parse


MySQL, MongoDB


Shopify Theme, Web Development, Full-stack, CSS5, Custom Shopify Apps, Vite, Algorithms, SEO Tools, Enterprise Resource Planning (ERP), Computer Science

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