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Jay Lee

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Senior Ruby on Rails Engineer

Seasoned Ruby on Rails engineer with 10+ years of experience building scalable, production-grade web platforms across e-commerce, healthcare, government, hyperlocal services, and judicial systems.

Specialized in Ruby on Rails backend architecture with strong frontend experience. Proven ability to design high-concurrency systems, refactor complex legacy platforms, and deliver reliable, maintainable solutions across multiple complex domains.

📧 lilee501@gmail.com | 📄 Download Resume | 💻 GitHub | 🔗 LinkedIn

Selected Experience Highlights

  • Designed and stabilized high-concurrency systems handling 4,000+ QPS during flash sales and burst traffic scenarios
  • Led end-to-end system architecture for complex platforms spanning e-commerce, healthcare, government procurement, and judicial systems
  • Successfully refactored and modernized legacy monolithic Rails systems, significantly improving stability and maintainability
  • Delivered regulatory-compliant systems used in real-world hospitals, courts, and government departments
  • Frequently acted as technical owner, independently handling requirement analysis, system design, stakeholder communication, and delivery
  • Experienced in both startup-scale rapid iteration and enterprise / public-sector long-cycle projects

Independent Software Consultant (Remote)

Freelance · Nov 2022 – Dec 2025

Provide maintenance, optimization, and feature development for business-critical production systems across multiple organizations.

Rather than working for a single employer, I collaborate with several clients in parallel, helping teams keep their platforms stable, maintainable, and evolving as their business grows.

Key engagements include:

  • Internal Project Management Platform (Redmine-based)

    • Maintained and extended a company-wide Redmine system used by product, engineering, and operations teams
    • Improved performance and usability for daily, high-volume internal use

  • Production E-commerce System (Java-based)

    • Provided continuous maintenance and feature development for a live online e-commerce system
    • Fixed bugs, improved stability, and implemented new business-driven features
    • Worked closely with business and operations teams to align technical changes with real customer and revenue needs

Tech Stack
Ruby on Rails, Java, React, PostgreSQL, Redis

Online Hospital Platform (Internet Hospital)

Senior Ruby on Rails engineer
Beikang Yizhong Medical Technology (China) | Dec 2021 – Nov 2022

Cloud-based telemedicine platform supporting online registration, appointments, payments, video consultations, and e-prescriptions, integrated with hospital HIS systems.

Key Contributions & Impact

  • Led backend architecture and core module development from concept to production
  • Designed async HIS integration layer for isolated intranet hospital systems
  • Implemented Sidekiq-based workflows for compliance, synchronization, and reporting
  • Coordinated directly with hospitals and vendors, ensuring smooth integration and delivery
  • Delivered a production-grade, compliant system actively used in real hospital environments

Tech Stack
Ruby on Rails, React, PostgreSQL, Mysql, Redis

Hyperlocal Services Platform

Senior Ruby on Rails engineer
Partner Vision InfoTech (China) | Oct 2019 – Dec 2021

Multi-module local life platform combining e-commerce, resource monetization, and community social features.

Key Contributions & Impact

  • Designed modular backend supporting products, resources, and community systems
  • Led full lifecycle development: requirements, architecture, implementation, deployment
  • Enabled rapid business iteration through flexible, decoupled system design
  • Delivered a stable platform supporting continuous feature experimentation

Tech Stack
Ruby on Rails, React, PostgreSQL, Redis, Sidekiq, Docker, GitLab CI/CD

Government Procurement & Bidding Platform

Senior Ruby on Rails engineer
Beijing Sunshine Procurement | Oct 2018 – Oct 2019

Large-scale public-sector platform supporting government procurement and public tendering workflows.

Key Contributions & Impact

  • Refactored a tightly coupled legacy bidding system into a maintainable Rails architecture
  • Optimized database queries and indexing for large-scale datasets
  • Acted as core technical contact for government stakeholders and vendors
  • Successfully delivered a production system used in real procurement scenarios

Tech Stack
Ruby on Rails, MySQL, Redis, Sidekiq, Elasticsearch

Court Case Management System (Judicial Platform)

Senior Ruby on Rails Developer
Beijing Jingyu Network Technology | Nov 2017 – Oct 2018

Judicial platform digitizing the full lifecycle of court case handling.

Key Contributions & Impact

  • Led end-to-end project delivery for multiple court deployments, ensuring on-time, stable launches in on-premise judicial environments.
  • Conducted requirement analysis and review sessions with judges, court staff, and stakeholders, translating legal workflows into actionable technical plans.
  • Coordinated cross-functional teams (backend, frontend, QA, and deployment) to drive execution, track progress, and resolve delivery risks.
  • Managed sprint planning, task breakdown, and development priorities to ensure steady progress and predictable releases.
  • Served as the primary communication bridge between legal domain experts and the engineering team, reducing ambiguity and rework

Tech Stack
Ruby on Rails, MySQL, MongoDB, Redis, Sidekiq, Apache Solr

Distribution E-commerce Platform

Senior Ruby on Rails engineer
Guangzhou Lige InfoTech (China) | Sep 2015 – Oct 2017

High-concurrency social commerce platform focused on flash sales, group buying, and three-level referral distribution.

Key Contributions & Impact

  • Led refactoring of flash sale and commission settlement systems
  • Introduced async pipelines using Sidekiq to offload heavy order, payment, and commission processing
  • Enabled stable handling of 4,000+ QPS during synchronized flash sale traffic
  • Significantly reduced system crashes and infrastructure costs through performance optimization

Tech Stack
Ruby on Rails, React, MySQL, Redis, Sidekiq, Nginx

ShopperPlus.ca (E-commerce Platform)

Ruby on Rails Engineer
ShopperPlus Canada | Jan 2013 – Sep 2015

Full-featured e-commerce platform serving consumer electronics and daily goods.

Key Contributions & Impact

  • Built and evolved the entire e-commerce platform from the ground up, covering both customer-facing storefront and internal management systems.
  • Took full ownership of the system as the business scaled, continuously improving database design, application architecture, and system performance to support growing traffic and data volume.
  • Led ongoing refactoring to improve code readability, modularity, and long-term maintainability as business complexity increased.
  • Actively participated in requirement reviews, feature planning, and release cycles, ensuring fast and reliable delivery aligned with business needs.
  • Actively incorporated user feedback and frontline customer support insights into technical decisions, ensuring the platform continuously evolved to meet real user needs while maintaining a high-quality user experience and operational efficiency.

Tech Stack
Ruby on Rails, MySQL, Redis, Sidekiq, Elasticsearch, AWS

Skills Snapshot

Languages
- Ruby, JavaScript

Backend & Architecture
- Ruby on Rails
- High-concurrency system design
- Async & event-driven architectures
- Legacy monolith refactoring

Frontend
- React.js (SPA, admin dashboards)
- Frontend–backend separation

Databases & Search
- PostgreSQL, MySQL
- Redis
- Elasticsearch

DevOps & Infrastructure
- Docker, Kubernetes
- GitLab CI/CD, GitHub Actions
- Nginx
- AWS, Alibaba Cloud

What I Bring

  • Strong ownership mindset with the ability to drive complex systems end-to-end
  • Deep understanding of real-world production constraints
  • Comfortable working across business, technical, and regulatory boundaries
  • Focused on building systems that scale, survive traffic spikes, and remain maintainable