Adrian is available for hire
Hire AdrianAdrian Shum
Verified Expert in Engineering
Back-end Developer
Hong Kong, Hong Kong
Toptal member since April 29, 2022
Bio
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.
Portfolio
Moovup
Amazon Web Services (AWS), Clojure, React, TypeScript, Elasticsearch...
Goxip
Go, Elasticsearch, ELK (Elastic Stack), MySQL, Kubernetes, Apache Airflow...
MyMM
Node.js, AngularJS, Elasticsearch, Go, Docker, Redis, Microservices, MySQL...
Experience
- Redis - 10 years
- MySQL - 10 years
- Node.js - 10 years
- Elasticsearch - 8 years
- Go - 8 years
- Docker - 7 years
- Microservices - 7 years
- gRPC - 3 years
Preferred Environment
Go, TypeScript
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
Senior Software Engineer
2024 - 2026
Moovup
- Handled full-stack functional programming. Standardized functional paradigms across the stack using Clojure for back-end services and a loader-based architecture for the React employer portal.
- Performed Elasticsearch optimization. Tuned cluster performance, shard allocation, and indexing. Implemented a synonym system and prototyped Vector Search for semantic retrieval.
- Contributed to document processing. Built a hybrid Clojure/Python pipeline using Google Document AI to extract and validate data from Business Registration (BR) documents.
- Handled React architecture. Migrated the employer portal to a modern SPA, declarative data loaders to eliminate render waterfalls and side-effect bugs.
Technologies: Amazon Web Services (AWS), Clojure, React, TypeScript, Elasticsearch, Full-stack Development, Tailwind CSS, Back-end Development, Next.js, Distributed Systems, API Integration, Third-party APIs, Payment APIs, Architecture, Natural Language Processing (NLP), Search Engines, Vector Search, Large Language Models (LLMs), Prompt Engineering
System Architect
2018 - 2024
Goxip
- Built a system architecture that scales through 800 merchants, 12 million stock-keeping units (SKUs), 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 Pandas.
- 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 (SNS), AWS Lambda, Lambda Functions, APIs, CI/CD Pipelines, eCommerce APIs, Integration, Shopify API, eCommerce, Marketing, Back-end Development, Full-stack Development, React, RESTFul APIs, Tailwind CSS, Distributed Systems, API Integration, Third-party APIs, Payment APIs, Architecture, Leadership, Natural Language Processing (NLP), Recommendation Systems, Search Engines, FastAPI
Platform Architect
2015 - 2018
MyMM
- 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 the 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 (SNS), Apache Kafka, APIs, CI/CD Pipelines, eCommerce APIs, eCommerce, Back-end Development, Java, RESTFul APIs, Distributed Systems, API Integration, Third-party APIs, Payment APIs, Architecture, Leadership, Natural Language Processing (NLP), Recommendation Systems, Search Engines
Full-stack Developer
2014 - 2015
Imagination
- 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, Full-stack Development, RESTFul APIs, Back-end Development, Distributed Systems, API Integration, Third-party 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, Full-stack Development, Education Technology (Edtech)
Freelance Web Developer
2012 - 2012
WE-DESIGNS
- Developed websites of WE-DESIGNS and CUHK School of Architecture.
- Handled web development with Kohana PHP, jQuery, and Flickr API integrations.
- Assisted in the virtual private server (VPS) hosting, server deployment, and SEO.
Technologies: PHP, JavaScript, SQL, Software Development, HTML, CSS, Full-stack Development
Experience
Imagor
https://github.com/cshum/imagorImagor 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.
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.
Imagor Studio
https://studio.imagor.net/As the author of Imagor Studio, I architected a high-performance, open-source image ecosystem engineered for massive scale, built with Go and libvips. I developed a zero-indexing virtual gallery that enables instant navigation of tens of thousands of assets via multi-threaded metadata processing and optimized virtual scrolling. To empower professional workflows, I engineered a non-destructive editor supporting real-time, multi-layer compositing and URL-based transformations, ensuring original files remain untouched while providing dynamic previews. By implementing universal storage compatibility across S3, R2, and local filesystems, I created a robust, production-ready infrastructure that currently handles millions of requests in high-concurrency environments.
vipsgen
https://github.com/cshum/vipsgenvipsgen is an automatic code generator for creating type-safe, comprehensive Go bindings for the high-performance image processing library, libvips. It solves the maintenance and completeness issues faced by older, manually written Go bindings (like govips) by using libvips's GObject introspection data to generate up-to-date and reliable Go code.
Goxip
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.
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)
https://nomoreclub.io/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.
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.
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.
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
https://www.nwd.com.hk/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.
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.
The most popular online music widget during the Tumblr era. Peaked six million daily page views and one million MAU.
Education
2008 - 2012
Bachelor's Degree in Mathematics and Computer Science
Imperial College London - London, UK
Skills
Libraries/APIs
Node.js, React, REST APIs, Cache API, Pandas, Vue, Libvips, Shopify API
Tools
ELK (Elastic Stack), Apache Airflow, RabbitMQ, Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (SNS), Google Analytics
Languages
Go, JavaScript, PHP, SQL, TypeScript, HTML, CSS, Python, GraphQL, Java, Solidity, Clojure
Frameworks
AngularJS, gRPC, Knockout (Knockout.js), Nuxt.js, Next.js, Tailwind CSS
Paradigms
Microservices, REST, Microservices Architecture, Test-driven Development (TDD), Clean Architecture, ETL
Platforms
Drupal 7, Docker, Amazon Web Services (AWS), Kubernetes, Apache Kafka, AWS Lambda, Blockchain, Ethereum
Storage
Elasticsearch, MySQL, Redis, Redis Cache, PostgreSQL, MongoDB, NoSQL
Industry Expertise
Marketing
Other
RESTful Microservices, Cloud Architecture, Data Architecture, Software Development, Back-end, Software Architecture, Containerization, APIs, CI/CD Pipelines, eCommerce, Back-end Development, Architecture, Domain-driven Design (DDD), Distributed Caches, Analytics, Web Analytics, Decentralization, Decentralized Systems, Decentralized Applications, Data Engineering, Data Analysis, Data Warehousing, Big Data, Non-fungible Tokens (NFT), Lambda Functions, eCommerce APIs, Integration, Full-stack Development, Distributed Systems, Payment APIs, Leadership, Natural Language Processing (NLP), Recommendation Systems, Search Engines, Vector Search, Large Language Models (LLMs), Prompt Engineering, CRDT, RESTFul APIs, API Integration, Third-party APIs, Education Technology (Edtech), FastAPI
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