Adrian Shum, Developer in Hong Kong, Hong Kong
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Adrian Shum

Verified Expert  in Engineering

Back-end Developer

Hong Kong, Hong Kong
Toptal Member Since
April 29, 2022

Adrian is an enthusiastic technologist with over ten years of experience, including eight years specifically in building complex eCommerce systems. Adrian consistently aims to craft robust and functional solutions that drive innovation within organizations.


Go, Elasticsearch, ELK (Elastic Stack), MySQL, Kubernetes, Apache Airflow...
Node.js, AngularJS, Elasticsearch, Go, Docker, Redis, Microservices, MySQL...
Node.js, AngularJS, Drupal 7, Redis, MySQL, REST, Elasticsearch, Docker, Go...




Preferred Environment


The most amazing...

...project I've created as a hobby is an online music widget website that reached six million daily page views and one million monthly active users (MAU).

Work Experience

Head of System Architecture

2018 - 2023
  • Built a system architecture that scales through 800 merchants, 12 million stock-keeping units (SKU), and 700,000 monthly active users on board.
  • Revamped mission-critical API services from PHP to Go, resulting in 10-fold to 100-fold better response time and uptime.
  • Handled Elasticsearch index, search relevancy, and cluster performance optimizations.
  • Facilitated structured logging and analytics with Elasticsearch, Fluent Bit, and Kibana.
  • Created product ranking algorithms based on multichannel sales and impressions data, which has increased Google Shopping ads' return on ad spend (ROAS) by over 200%.
  • Facilitated ETL data pipelines with a customized Airflow for Kubernetes and revamped ETL scripts from PHP to Python and Panda.
  • Reduced AWS cost by 60% using various cost-saving techniques, including spot instances, network optimizations, and Cloudflare integrations.
Technologies: Go, Elasticsearch, ELK (Elastic Stack), MySQL, Kubernetes, Apache Airflow, GraphQL, Nuxt.js, Vue, Docker, Redis, Microservices, gRPC, Python, Pandas, REST, RabbitMQ, REST APIs, Microservices Architecture, Domain-driven Design (DDD), JavaScript, RESTful Microservices, Test-driven Development (TDD), Solidity, Redis Cache, Cache API, Distributed Caches, SQL, MongoDB, Clean Architecture, TypeScript, Analytics, Google Analytics, ETL, Cloud Architecture, Amazon Web Services (AWS), Data Architecture, Software Development, Data Engineering, Data Analysis, Data Warehousing, Big Data, NoSQL, Back-end, Containerization, Software Architecture, HTML, CSS, Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (Amazon SNS), AWS Lambda, Lambda Functions, APIs, CI/CD Pipelines, eCommerce APIs, Integration, Shopify API, eCommerce, Marketing

Platform Architect

2015 - 2018
  • Built the back-end architecture for an eCommerce ​platform in China, consisting of native apps, H5 WeChat, and web admin, featuring product, inventory, order, coupon, CMS, and social.
  • Worked with back-end technologies: Node.js, ElasticSearch, MariaDB, Redis, RabbitMQ, and Kafka in developing the platform from scratch and its ongoing enhancements.
  • Led the local and remote team, performing task​ management and code​ ​review.
  • Integrated China payment gateway API Alipay and WeChat Pay.
Technologies: Node.js, AngularJS, Elasticsearch, Go, Docker, Redis, Microservices, MySQL, REST, RabbitMQ, REST APIs, RESTful Microservices, Microservices Architecture, JavaScript, Test-driven Development (TDD), ELK (Elastic Stack), Redis Cache, Cache API, SQL, Analytics, Web Analytics, Cloud Architecture, Software Development, Data Architecture, NoSQL, Back-end, Containerization, Software Architecture, HTML, CSS, Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (Amazon SNS), Apache Kafka, APIs, CI/CD Pipelines, eCommerce APIs, eCommerce

Full-stack Developer

2014 - 2015
  • Filled​ ​​​various​ development​ ​roles focusing on Node.js, AngularJS, and Drupal 7.
  • Built​ a ​replicable,​ ​decentralized​ ​CMS​ ​with​ ​Node.js,​ ​LevelDB​​, and​ ​Elasticsearch.​ ​Used​ ​as​ ​the back end​ ​on​ ​several​ ​digital​ ​projects​​, including​ ​GE​ ​Turkey.
  • Contributed​ ​to developing​ ​several​ ​touchscreen​ ​directory​ ​software​ ​for​ ​shopping​ ​malls​ ​and car​ ​personalization,​ ​including​ ​Pacific​ ​Place​ ​and​ ​Lincoln​ ​China.
Technologies: Node.js, AngularJS, Drupal 7, Redis, MySQL, REST, Elasticsearch, Docker, Go, Microservices, REST APIs, JavaScript, RESTful Microservices, Redis Cache, Cache API, SQL, PostgreSQL, Analytics, Google Analytics, CRDT, Cloud Architecture, Amazon Web Services (AWS), Software Development, NoSQL, Back-end, HTML, CSS, APIs

Drupal Developer

2013 - 2014
Coconut Inc.
  • Held various​ ​development​ ​roles​ focusing on ​Drupal​ 7.
  • Developed ​New​ ​World​ ​Development,​ ​Chow​ ​Tai​ ​Fook, and Arch Education websites.
  • Provided​ ​training​ to the client’s​ ​staff​ ​on​ ​content​ ​entry​ ​and​ ​site​ ​maintenance.
Technologies: Drupal 7, JavaScript, Redis, MySQL, REST, SQL, PostgreSQL, Analytics, Google Analytics, Amazon Web Services (AWS), Software Development, Back-end, HTML, CSS

Freelance Web Developer

2012 - 2012
  • Developed​ ​website​s ​of WE-DESIGNS and ​CUHK School​ ​of​ ​Architecture​​.
  • Handled web development with Kohana PHP, jQuery, and Flickr API integrations.
  • Assist​ed ​in the virtual private server (VPS) hosting,​ ​server deployment, and SEO.
Technologies: PHP, JavaScript, SQL, Software Development, HTML, CSS

Imagor is a fast, Docker-ready image processing server written in Go. It uses one of the most efficient image processing libraries, libvips, and is typically four to eight times faster than the quickest ImageMagick and GraphicsMagick settings.

It is a highly optimized application for concurrent requests, ready to be installed and used in any Unix environment, and is also prepared to be containerized using Docker.

Imagor adopts the Thumbor URL syntax and covers most of the web image processing cases representing a lightweight, high-performance drop-in replacement.


Goxip is an online fashion, clothing, and beauty search engine and eCommerce platform with over five million SKUs.

I was responsible for building the backbone architecture in Go with Elasticsearch, including search relevancy and cluster performance optimizations. Alongside with product ranking algorithms based on multi-channel sales and impressions data written in Python and Pandas managed by Airflow.

NOMORECLUB Non-fungible Token (NFT)
NOMORECLUB empowers creators by building a community as a create-to-earn stage. Holders can make a profit by co-creating NFTs and NOMORECLUB products.

In this project, I built the gas-saving solidity contract using ERC721A, signature-based whitelisting, a gas war reduction mechanism, and a secure Node.js back end.

GE Innovation Engine

The GE innovation engine is the ever-present brain within the GE Innovation Center. It is a dynamic online aggregator that visually represents what areas of innovation are trending globally. It allows visitors to connect and download countless academic resources such as the GE patent library, the Predix developer assets, stylus articles, and other academic journals.

I built the knowledge using Elasticsearch, powered by a ​replicable,​ ​decentralized ​CMS​ developed with ​Node.js and ​LevelDB.

Virtual Car Configurator for Lincoln China

Virtual car configurator visualized on a “true-to-scale” 4K video wall using 3D engineering models running on a content-managed cloud-based HTML5 platform, deployed across over 20 Lincoln dealerships across China.

I was responsible for developing the interactive interface with AngularJS and the vehicle configuration back end built in Node.js and LevelDB.

New World Development Company Limited | Official Website
I was responsible for the New World Development Company Limited's official website built with Drupal 7.

For this project, I laid out the foundations with Drupal 7, including content types, taxonomies, panels, views, workflows, and deployment strategy. I also supported the wide variety of corporate workflows and staff training for the company.

SCM Music Player
SCM Music Player is a free and open source web music player that brings a seamless music experience to your website.

The most popular online music widget during the Tumblr era. Peaked six million daily page views and one million MAU.
2008 - 2012

Bachelor's Degree in Mathematics and Computer Science

Imperial College London - London, UK


Node.js, REST APIs, Cache API, Pandas, Vue, React, Shopify API


ELK (Elastic Stack), Apache Airflow, RabbitMQ, Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (Amazon SNS), Google Analytics


AngularJS, gRPC, Knockout (Knockout.js), Nuxt.js


Go, JavaScript, PHP, SQL, HTML, CSS, Python, GraphQL, TypeScript, Solidity


Microservices, REST, Microservices Architecture, Test-driven Development (TDD), Clean Architecture, ETL


Drupal 7, Docker, Amazon Web Services (AWS), Kubernetes, Apache Kafka, AWS Lambda, Blockchain, Ethereum


Elasticsearch, MySQL, Redis, Redis Cache, PostgreSQL, MongoDB, NoSQL

Industry Expertise



RESTful Microservices, Cloud Architecture, Data Architecture, Software Development, Back-end, Software Architecture, Containerization, APIs, CI/CD Pipelines, eCommerce, Domain-driven Design (DDD), Distributed Caches, Analytics, Web Analytics, libVIPS, Decentralization, Decentralized Systems, Decentralized Applications, Data Engineering, Data Analysis, Data Warehousing, Big Data, Non-fungible Tokens (NFT), Lambda Functions, eCommerce APIs, Integration, CRDT

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