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Hi, I’m William Lee—a senior full-stack engineer with 8 years of delivering scalable web applications for Fortune 500 clients and startups. I specialize in React, Python, and Node.js, and I’m proficient across AWS and GCP. I design systems that scale to millions of users and prioritize performance, reliability, and thoughtful UX. I enjoy turning complex challenges into practical solutions by collaborating with product, design, and security teams, and I’m passionate about building maintainable code, automating workflows, and shipping features that make a difference.…Hi, I’m William Lee—a senior full-stack engineer with 8 years of delivering scalable web applications for Fortune 500 clients and startups. I specialize in React, Python, and Node.js, and I’m proficient across AWS and GCP. I design systems that scale to millions of users and prioritize performance, reliability, and thoughtful UX. I enjoy turning complex challenges into practical solutions by collaborating with product, design, and security teams, and I’m passionate about building maintainable code, automating workflows, and shipping features that make a difference.

William Lee

Full Stack Developer, Web Developer, Front-End Developer, +2

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Hi, I’m William Lee—a senior full-stack engineer with 8 years of delivering scalable web applications for Fortune 500 clients and startups. I specialize in React, Python, and Node.js, and I’m proficient across AWS and GCP. I design systems that scale to millions of users and prioritize performance, reliability, and thoughtful UX. I enjoy turning complex challenges into practical solutions by collaborating with product, design, and security teams, and I’m passionate about building maintainable code, automating workflows, and shipping features that make a difference.…Hi, I’m William Lee—a senior full-stack engineer with 8 years of delivering scalable web applications for Fortune 500 clients and startups. I specialize in React, Python, and Node.js, and I’m proficient across AWS and GCP. I design systems that scale to millions of users and prioritize performance, reliability, and thoughtful UX. I enjoy turning complex challenges into practical solutions by collaborating with product, design, and security teams, and I’m passionate about building maintainable code, automating workflows, and shipping features that make a difference.

Available to hire

Hi, I’m William Lee—a senior full-stack engineer with 8 years of delivering scalable web applications for Fortune 500 clients and startups. I specialize in React, Python, and Node.js, and I’m proficient across AWS and GCP. I design systems that scale to millions of users and prioritize performance, reliability, and thoughtful UX.

I enjoy turning complex challenges into practical solutions by collaborating with product, design, and security teams, and I’m passionate about building maintainable code, automating workflows, and shipping features that make a difference.

Skills

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Work Experience

Senior Software Engineer at Loka, Inc.

July 1, 2024 - Present

Built production AI agent infrastructure with multi-provider LLM routing (OpenAI, AWS Bedrock, Vertex AI) using LiteLLM. Developed LLM orchestration systems using LangChain, LangGraph, and MCP with memory chaining, tool integration, and multi-step task execution. Designed AI-powered HR automation platform with workflow execution engine handling resume parsing, candidate screening, and interview scheduling. Built observability and cost tracking pipelines with automated budget controls, reducing LLM operational costs by 30%. Automated AWS infrastructure (ECS, RDS, VPC) using Terraform and CDK accelerating client delivery by 40%.

Senior Software Engineer at Booz Allen Hamilton

June 1, 2022 - June 1, 2024

Developed production EHR platform for care coordination, managing patient enrollment, immunizations, and clinical workflows for healthcare providers. Implemented FHIR R4 compliance (45+ resource types) with bidirectional HL7 integration to California Immunization Registry for real-time data exchange. Built Chrome Extension embedding clinical tools into Elation EHR using DOM injection, enabling staff to access patient data without leaving their workflow. Optimized patient list rendering for 1,000+ records using virtualization and client-side search, eliminating server roundtrips. Engineered batch synchronization engine processing daily immunization syncs across patient populations with real-time progress tracking.

Consulting Software Engineer at Milestone Technologies, Inc.

May 1, 2020 - May 1, 2022

Developed K-12 education platform with absence management system serving millions of users. Led Angular to React migration, modernizing frontend architecture and improving performance. Automated CI/CD pipelines using Google Cloud Build and Cloud Deploy with containerization and multi-environment promotion.

Software Engineer at Accenture

June 1, 2017 - March 1, 2020

Developed enterprise applications delivering custom features and system integrations. Built RESTful APIs and backend services supporting client-facing applications across multiple projects. Performed SAP system customizations and integrations, extending core functionality for enterprise clients.