TONY LEE
SENIOR AI / FULL-STACK ENGINEER
+1 929 233 9052 | tonyylee.official@gmail.com | Memphis, TN | linkedin.com/in/tony-lee-4769ba3b8

SUMMARY
Senior AI / Full-Stack Engineer with 10 years of building and scaling production-grade systems across SaaS and
AI-driven platforms. Deep expertise in LLM applications, RAG pipelines, and real-time AI systems, with a strong
focus on system design, performance optimization, and multi-tenant architectures. Proven ability to own end-to-end
delivery - from prototyping to production - across high-impact, data-intensive environments.

WORK EXPERIENCE
TheKey
Generative AI Engineer | Jan 2024 - Present
- Built LLM-powered features for internal healthcare tools, allowing users to query patient-related data and workflows
  in a more natural way instead of navigating multiple systems.
- Designed and iterated on RAG pipelines combining structured data and unstructured documents, improving retrieval quality
  and reducing manual lookup.
- Implemented backend services in Python (FastAPI) to support real-time AI responses, including streaming outputs and
  session-aware interactions.
- Integrated embedding-based retrieval using vector search, tuning chunking strategies and retrieval logic to improve
  consistency across similar queries.
- Worked closely with product to refine prompt design, response formats, and guardrails, improving reliability and
  usability in real-world workflows.
- Implemented authentication, session management, and access control, ensuring secure handling of sensitive healthcare data.
- Identified bottlenecks in retrieval and generation pipelines, improving latency through async processing and lightweight
  caching.
- Structured the system to support extensible AI use cases (chat, summarization, workflow automation) without major refactoring.

Google (Google Cloud)
AI Research Engineer (LLM Systems) | Jan 2023 - Oct 2023
- Worked on LLM-based pipelines for document processing and semantic search, improving how large datasets are indexed and queried.
- Built embedding-based retrieval systems, experimenting with indexing strategies and similarity search.
- Used GCP tools such as Vertex AI and BigQuery to run experiments, process data, and support model-driven workflows.
- Improved data pipelines for indexing, retrieval, and preparation of model inputs.
- Helped transition research prototypes into more stable, production-oriented pipelines by improving data handling and system reliability.
- Collaborated with engineers and researchers to evaluate model outputs and refine retrieval and generation behavior.

HubSpot
AI Full-Stack Engineer | Mar 2020 - Dec 2023
- Built and maintained backend services using Node.js and Python, supporting high-volume SaaS workflows and integrations across multiple systems.
- Designed REST APIs for data-heavy operations with a focus on reliability, clear contracts, and long-term maintainability as product requirements evolved.
- Improved database performance by analyzing slow queries, adding indexes, and optimizing data access patterns in critical services.
- Introduced Redis-based caching to reduce repeated load on core endpoints and improve response times.
- Contributed to frontend development using React and Next.js, improving usability and reducing friction in key user flows.
- Worked on early AI-driven features, including automation and data enrichment, integrating them into existing product workflows.
- Participated in system design discussions around scaling services and maintaining system reliability.
- Improved CI/CD pipelines and deployment processes, reducing release issues and increasing consistency.

Squarespace
Software Engineer | Jun 2017 - Feb 2020
- Developed full-stack features for web applications, including backend APIs and frontend components used in customer-facing products.
- Built and maintained services for content management systems and user-related workflows.
- Improved frontend performance by addressing rendering issues and optimizing key UI interactions.
- Collaborated with product and design teams to deliver features that balanced usability with technical constraints.

AutoZone
Software Engineer Intern | Jul 2016 - May 2017
- Assisted in building internal tools and web applications as part of a larger engineering team.
- Supported debugging, testing, and incremental feature development across backend and frontend components.
- Applied standard development practices including version control, code reviews, and collaborative workflows.

University of Texas at Dallas
Research Assistant | Aug 2015 - Dec 2016
- Built Python-based tools for data processing and experimentation in research projects.
- Assisted with early-stage machine learning workflows and data analysis.
- Supported implementation and documentation of research systems.

TECHNICAL SKILLS
AI/ML:
LLMs (OpenAI, Anthropic APIs), RAG (Retrieval-Augmented Generation), Embedding & Vector Search, Semantic Search, Prompt Engineering,
Retrieval Optimization (chunking, ranking), LLM Evaluation & Output Tuning, AI Agents / Workflow Automation, NLP (Natural Language Processing),
Knowledge Augmentation Systems, Context Injection / Memory Handling, LangChain / LLM Orchestration frameworks.

Backend:
Python, FastAPI, Node.js (Express / backend services), REST APIs, WebSockets, Async Processing / Concurrency,
Microservices Architecture, Distributed Systems, Event-Driven Architecture, API Design & Contract Design,
Authentication & Authorization (RBAC, JWT), Session Management, Multi-tenant Systems, System Design & Scalability,
Performance Optimization, Caching Strategies.

Frontend:
React, Next.js, TypeScript, JavaScript (ES6+), State Management (Context, Redux basics),
Component Design, Frontend Performance Optimization, Responsive UI Development.

Data & Storage:
PostgreSQL, MongoDB, Redis (Caching), Vector Databases (Pinecone, Weaviate, FAISS), BigQuery,
Data Modeling, Query Optimization, Indexing Strategies.

Cloud & Infrastructure:
AWS, GCP (Vertex AI, BigQuery, Cloud Functions), Docker (Containerization), CI/CD Pipelines (GitHub Actions),
Cloud-native Architecture, Deployment & Monitoring Basics, Scalable Infrastructure Design.

Databases:
PostgreSQL, MySQL, Vector Databases, Database Schema Design, Query Optimization, Indexing Strategies, Caching.

Engineering Practices:
System Design, Code Review, Debugging & Troubleshooting, Performance Profiling, Agile / Iterative Development,
Cross-functional Collaboration, Technical Decision Making.

EDUCATION
Bachelor of Science (B.Sc.), Computer Science | 2012 - 2016
The University of Texas at Dallas