Senior Full-stack engineer with Ruby on Rails & Shopify Development expertise and 8+ years of experience building scalable web applications, Shopify themes, and custom Shopify apps. Skilled in backend architecture (Rails, Node.js), modern frontend development (React, Next.js, Tailwind), and high-performance eCommerce experiences. Strong understanding of Liquid, Shopify APIs, metafields, checkout customization, and performance optimization. Additional background in game engineering, casino platforms, and AI-driven interactive systems.…

Lucas Lee

Senior Full-stack engineer with Ruby on Rails & Shopify Development expertise and 8+ years of experience building scalable web applications, Shopify themes, and custom Shopify apps. Skilled in backend architecture (Rails, Node.js), modern frontend development (React, Next.js, Tailwind), and high-performance eCommerce experiences. Strong understanding of Liquid, Shopify APIs, metafields, checkout customization, and performance optimization. Additional background in game engineering, casino platforms, and AI-driven interactive systems.…

Available to hire

Senior Full-stack engineer with Ruby on Rails & Shopify Development expertise and 8+ years of experience building scalable web applications, Shopify themes, and custom Shopify apps. Skilled in backend architecture (Rails, Node.js), modern frontend development (React, Next.js, Tailwind), and high-performance eCommerce experiences. Strong understanding of Liquid, Shopify APIs, metafields, checkout customization, and performance optimization. Additional background in game engineering, casino platforms, and AI-driven interactive systems.

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Skills

Experience Level

Ruby on Rails
Expert
Ruby
Expert
AWS
Expert
TypeScript
Expert
Shopify
Expert
PostgreSQL
Expert
Docker
Expert
Node.js
Expert
Redis
Expert
GraphQL
Expert
MySQL
Expert
React JS
Expert
React Native
Expert
Kubernetes
Expert
Express
Expert
api
Expert
Python
Expert
Ethers.js
Intermediate
Django
Intermediate
Solidity
Intermediate
TensorFlow
Intermediate
Golang
Intermediate
Go
Intermediate
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Language

English
Fluent

Work Experience

Frontend Engineer at Freelance – Independent Projects
December 1, 2024 - Present
Led 40+ production React and Next.js applications for diverse clients. Implemented SSR/ISR and code-splitting to reduce page load times by 1.8–3.2s and boosted Lighthouse performance by 28–52%. Built 20+ reusable UI libraries with TypeScript and Tailwind, reducing future dev time by ~36%. Integrated REST and GraphQL APIs to cut client-side latency by ~25%. Developed reusable hooks and state systems, reducing bugs by ~22%. Shopify eCommerce development across 30+ stores with dynamic sections and metafield-driven CMS; optimized storefronts to achieve 85–95 Analyzer scores and a 12–34% conversion lift. Built 12+ custom Shopify apps using Rails and Node.js (subscriptions, loyalty, bundles, AI recommendations, analytics dashboards) and automated inventory/orders/integrations (20–50% workload reduction). Implemented Shopify Scripts, Functions, and checkout extensibility; integrated 20+ tools (Klaviyo, Recharge, Gorgias, ERP/POS). nopCommerce development across 8+ enterprise stores;
Senior Ruby on Rails Developer at BrainCave
December 1, 2022 - November 1, 2024
Delivered 15+ Rails applications including marketplaces, subscriptions, dashboards, and analytics systems. Improved API throughput by 45–70% using Postgres and Redis; achieved 80–92% test coverage with RSpec and FactoryBot. Built CI/CD pipelines with GitHub Actions, reducing release time by 50%. Casino betting game development: 12+ betting engines handling 2,000–5,500 concurrent users with <60ms latency; RNG and fairness verification; AI-based game balancing with 1M+ test rounds; animated casino UIs with Phaser/WebGL boosting retention by 18–25%. Blockchain and AI integrations: 4+ smart contracts for tokens, staking, and rewards; cryptographic fairness proofs; AI-driven bot behavior models; automated blockchain payout and verification tools.
Software Engineer (Full Stack) at Span.io
January 1, 2022 - November 1, 2022
Built an entire React Native installation app in 21 days for a hardware launch; integrated IoT device pairing and telemetry with 99.2% reliability. Reduced app crash rate by 28% and load time by 34%. Built real-time data pipelines using GraphQL and WebSockets; implemented authentication, offline mode, and OTA updates. Built CI/CD pipelines reducing deployment errors by 90%. Created automated hardware and UI tests, increasing regression coverage to 70%+.
Full Stack Engineer at BlueSG
April 1, 2021 - December 1, 2021
Rebuilt backend systems for rental and billing supporting 1M+ annual transactions. Designed microservices including full Rental Service lifecycle. Reduced external dependency by 63%, improving API speed by 27%. Reduced technical debt by 40% through modular refactors. Increased test coverage to 72%+. Reduced rental incidents by 35% through better monitoring.
Frontend Engineer at Independent Project (Freelance)
December 1, 2024 - Present
Delivered high-performance, scalable frontends for 40+ projects using React and Next.js; improved Lighthouse performance by 28-52% on average; reduced page load times by 1.8-3.2 seconds via SSR/ISR and code-splitting; built 20+ custom UI component libraries with TypeScript and Tailwind CSS; integrated REST and GraphQL APIs; implemented reusable hooks, state machines, and data pipelines that cut client-side bugs by 22%.
Software Engineer (Full-stack) at Span.io
January 1, 2022 - November 30, 2022
Delivered mission-critical mobile app in 3 weeks; built React Native installation app in 21 days; integrated IoT flows (device pairing, panel activation, live energy streams) with 99.2% action reliability; led front-end development across 3 mobile apps; implemented reusable UI systems, caching layers, and error handling, reducing app crash rates by 28%; improved load times by ~34% via optimized bundle size and background sync logic; delivered real-time panel telemetry via GraphQL/WebSocket; automated CI/CD & testing, reducing deployment risk by 40%.
Fullstack Engineer at BlueSG
April 1, 2021 - December 31, 2021
Rebuilt core backend systems to support high-volume rental, billing, and fleet operations; designed and developed multiple backend microservices, including the Rental Service; reduced external service dependency by 63%, resulting in 27% faster API response times and significantly higher reliability; refactored legacy modules into modular, extensible architectures, decreasing future development effort by ~40%; implemented unit, integration, and end-to-end tests, increasing test coverage to 72%+; improved error handling and monitoring, reducing rental-related incidents by over 35%.

Education

Bachelor of Computing (Honors), Computer Science at National University of Singapore
January 1, 2017 - January 1, 2021
Bachelor's in Computing (Hons), Computer Science at National University of Singapore
January 1, 2017 - December 31, 2021

Qualifications

Add your qualifications or awards here.

Industry Experience

Software & Internet, Retail, Media & Entertainment, Professional Services, Gaming
    paper Full Stack Engineer | eCommerce Developer

    Built a high-performance eCommerce website using Next.js and modern web technologies. The platform supports a large product catalog, fast search and filtering, secure checkout, and responsive design. Focused on SEO, speed, and scalability using server-side rendering and optimized APIs. Designed to handle high traffic while delivering smooth user experience.

    Tech Stack: Next.js, React, TypeScript, Node.js, REST/GraphQL APIs, Tailwind/SCSS, Stripe/PayPal, Cloud hosting (Vercel/AWS), CI/CD.

    paper Full-Stack Developer – AI Crypto Trading Platform

    Built an end-to-end AI-based crypto trading platform, handling both frontend and backend development.

    Key Contributions:

    Developed responsive frontend using React.js for real-time trading dashboards and analytics

    Built backend services with Node.js for trade execution, data processing, and API integration

    Integrated AI models for market prediction and automated trading strategies

    Designed REST APIs for secure communication between frontend, backend, and AI services

    Implemented authentication, user management, and trade history tracking

    Optimized performance for real-time market data handling

    Tech Stack: React, Node.js, Express, REST APIs, WebSockets, AI/ML integration, Crypto APIs