Chris is available for hire
Hire ChrisChris Lee
Verified Expert in Engineering
Software Developer
Los Angeles, CA, United States
Toptal member since October 3, 2017
Bio
Chris Lee is a principal back-end/platform engineer delivering cloud‑native, multi‑cloud (AWS/GCP/Azure) services on Kubernetes with Docker and GitHub Actions/Cloud Build. He excels at high-throughput async APIs, secure authentication (SAML/OAuth), and event-driven pipelines with queues/streaming. He has demonstrated a proven impact through faster tenant onboarding, automated data/search connectors, and resilient services with strong observability, cutting ops toil and boosting reliability.
Portfolio
Indico Data Solutions
TensorFlow, Scikit-learn, PostgreSQL, SQLAlchemy, Tornado, Python...
HENDRY REAL ESTATE SERVICES, INC.
Python, OpenAI GPT-4 API, Artificial Intelligence (AI)...
Codegen, Inc.
Python, PostgreSQL, FastAPI, SQLAlchemy, Artificial Intelligence (AI), OpenAI...
Experience
- Python 3 - 11 years
- Python - 8 years
- Object-oriented Programming (OOP) - 8 years
- APIs - 5 years
- SQLAlchemy - 5 years
- Agile Software Development - 4 years
- Data Scraping - 4 years
- Docker Compose - 2 years
Preferred Environment
Docker, Ubuntu, MacOS
The most amazing...
...thing I've built is Indico’s infra to stream terabytes daily with 99.9% uptime, unlocking AI/ML-driven revenue for customers.
Work Experience
Principal Engineer
2015 - PRESENT
Indico Data Solutions
- Designed and integrated new technologies into an incredibly large and complex microservices infrastructure.
- Mentored multiple teams of engineers and guided them in the design and development of features.
- Built, maintained, and deployed back-end services for data visualization tools, data analysis, and custom machine learning model training tools (Indico's Crowdlabel).
- Developed, maintained, and deployed a machine learning API server with several gigabytes of machine learning models behind the scenes.
- Constructed in-house deployment utilities for AWS, Azure Cloud, and Google Compute Engine capable of spinning up several clusters of API workers with a simple script.
- Created a scheduling service that extracts information via scraping an API from several online mediums, performs a series of text analyses (keywords, topics, text features, sentiment, and more), and continuously builds a text corpus.
- Developed and maintained client libraries and SDKs for machine learning APIs across several different languages, including Python, Java, Android, JavaScript (Node.js), Ruby, PHP, and until recently, R.
- Set up continuous integration on all projects using Docker, Docker Compose, and CodeShip (Jet).
- Improved large data ETL and database transactions by optimizing speed and memory consumption.
- Managed the infrastructure in Kubernetes and deployed a series of Celery pipelines woven together with a Redis-result store and a RabbitMQ cluster broker.
Technologies: TensorFlow, Scikit-learn, PostgreSQL, SQLAlchemy, Tornado, Python, Google Compute Engine (GCE), Azure Cloud Services, Amazon Web Services (AWS), Docker, NumPy, Data Scraping, Object-oriented Programming (OOP), Async/Await, Distributed Systems, Containerization, Python 3, AI Architecture, Technical Leadership, Cloud, Full-stack, Machine Learning Operations (MLOps), Engineering Management, System Architecture, Claude Code, Anthropic, OpenAI API, SQL, API Integration
Software Engineer
2025 - 2025
HENDRY REAL ESTATE SERVICES, INC.
- Developed a generic framework to extract fields configured by the user from PDFs using LangGraph and LLMs.
- Implemented a hybrid semantic search to supplement the LLM agent.
- Implemented features to allow the full configuration and fine-tuning of the agent framework without code changes.
Technologies: Python, OpenAI GPT-4 API, Artificial Intelligence (AI), Natural Language Processing (NLP), Optical Character Recognition (OCR), PDF, Python 3, Cloud, Full-stack, System Architecture, Claude Code, Anthropic, OpenAI API, SQL, API Integration
Python Back-end Developer
2024 - 2025
Codegen, Inc.
- Designed and implemented sandbox tooling that enabled AI agents to securely load and execute commands on customer codebases.
- Refactored and optimized the error-raising framework—overhauled exception handling, logging, and tracking mechanisms—to reduce uncaught errors, denoise error tracking, and streamline debugging workflows.
- Architected and developed a comprehensive integration test suite using mocking and dependency injection.
Technologies: Python, PostgreSQL, FastAPI, SQLAlchemy, Artificial Intelligence (AI), OpenAI, Supabase, Modal, Python 3, AI Architecture, Technical Leadership, Cloud, Machine Learning Operations (MLOps), System Architecture, Claude Code, Anthropic, OpenAI API, SQL, API Integration
AI Developer
2023 - 2023
Intellibridge LLC
- Developed ETL connectors to load data from internal systems via API and sync them into a vector database for use as a retriever.
- Integrated with MetaGPT project communicating over Amazon SQS queues.
- Set up a Milvus cluster using Terraform and Kubernetes with monitoring and Kafka metrics.
Technologies: Django, JavaScript, Python, Node.js, React, Artificial Intelligence (AI), Python 3, AI Architecture, Cloud, Full-stack, Machine Learning Operations (MLOps), System Architecture, SQL, API Integration
Back-end Developer | Python and API Design
2022 - 2022
Metalenz, Inc.
- Developed a user portal to host installers locked behind user authentication.
- Built an administrative interface tool to manage the database for the user portal.
- Developed a camera SDK for Metalenz's proprietary camera hardware.
Technologies: Python, APIs, API Design, Camera API, Python 3, SQL, API Integration
SDK Engineer
2022 - 2022
Metalenz
- Built Python API for camera hardware and calibration processes.
- Helped integrate camera hardware into desktop GUI application, using PyQT5 and the API I developed.
- Built the user portal back end and front end on FastAPI, SQLAlchemy, and React to provide authenticated file access to users.
Technologies: React, Python 3, Poetry, SDKs, APIs, PyQt 5, HTTP Server, Python Asyncio, PostgreSQL, FastAPI, Object-oriented Programming (OOP), Async/Await, Containerization, CI/CD Pipelines, JavaScript, Microservices, API Integration
SQLAlchemy Consultant
2020 - 2021
JEFuller
- Served as a database consultant on how to improve the database structure and database queries.
- Performed a high-level audit of an existing system and created a low-to-high priority action items report.
- Assisted in debugging nondeterministic behavior with database connection management. Refactored the codebase to have cleaner and more reliable database connection logic.
Technologies: Python 3, SQLAlchemy, Docker, Python, Object-oriented Programming (OOP), Async/Await, Containerization, SQL
Software Developer
2019 - 2020
TargetSmart
- Developed TargetSmart APIs on AWS Lambda. Maintained, modified, and tested APIs as necessary.
- Queried database information from an AWS Aurora SQL database.
- Developed auto-example API generation for client-facing documentation.
- Supported the updating and adding documentation to new APIs.
Technologies: Pandas, AWS Lambda, Python, SQLAlchemy, Docker, Object-oriented Programming (OOP), Async/Await, Containerization
Python Developer
2018 - 2020
Ontic
- Interfaced with several crypto-exchange APIs like KuCoin, Binance, Bittrex, Bitfinex, OKEx, Poloniex, Huobi, and CCXT.
- Used REST APIs and WebSocket APIs to acquire data in real time.
- Saved time-sensitive data into a Redis database and enabled database clients to retrieve data through a simple interface.
- Developed async IO implementations for asynchronous operations.
- Used cfscrape (a Python library) to bypass a Cloudflare anti-bot page.
Technologies: PostgreSQL, Redis, Python, Docker, NumPy, Data Scraping, Object-oriented Programming (OOP), Async/Await, Containerization, API Integration
Python and Facebook API | Developer
2018 - 2019
Lerderian, Inc. (via Toptal)
- Created a series of recurring data ETL tasks for API data from Facebook and Instagram.
- Developed an image downloader and vectorizer and stored the data in PostgreSQL for future use in image analysis.
- Built an HTTP Server to trigger ETL tasks, synced Facebook accounts through OAuth 2, and performed analysis tasks on data.
- Created a database schema that allows for plug-and-play data ETL types from different API endpoints.
- Developed a sophisticated command-line tool to interface with an aiohttp server.
Technologies: Facebook Open Graph API, RedBeat, Docker, Celery, Python 3, SQLAlchemy, Python, Data Scraping, Object-oriented Programming (OOP), Async/Await, Distributed Systems, Microservices, JavaScript, API Integration
Software Developer
2018 - 2018
Seven Hills
- Handled the ingressing and processing of Google Sheet data via the Google API.
- Designed an interface for Windows executable to run browser automation and data collection.
- Automated the Windows COM API for a desktop application.
Technologies: Google Sheets API, Selenium, Docker, Python, Data Scraping, Object-oriented Programming (OOP), Async/Await, Python 3
Software Developer
2018 - 2018
IDEA Public Schools
- Automated scraping data from web portal.
- Queried MS SQL database across multiple tables for aggregate and time-series information.
- Generated multi-sheet Excel workbooks with formatting and formulas.
- Automated weekly/monthly report generation using a Windows scheduler.
Technologies: COM, Microsoft, Selenium, Docker, Python, Object-oriented Programming (OOP)
Android Developer Intern
2014 - 2015
Hangtime, Inc.
- Used LruCache and preloading to create smooth scrolling and fragment transitions.
- Built generalized adapters to use the same item caching and loading techniques across the application—decreasing the amount of additional logic and maintenance in the codebase.
- Created custom animations for spinners, loading screens, and sliding notifications and banners.
- Implemented a variety of intents for deep linking, third-party activity linking (camera, SMS, email, and other social media apps).
- Reduced the source code to less than half of the original while adding twice the amount of features—bringing the product to feature completeness.
Technologies: Content, Responsive, Google API, Facebook API, Google Maps API, Android SDK, Android Studio, Docker, Object-oriented Programming (OOP)
Experience
Instagram Content Automation
Architected and developed a production-ready, full-stack automated content creation system that generates vertical video slideshows from real estate listings and publishes them to Instagram on a configurable schedule. The system processes listings from a REST API, captures screenshots using headless browser automation, generates MP4 videos with FFmpeg, and manages the complete Instagram publishing workflow via the Instagram Graph API.
CONTRIBUTIONS
• Integrated Puppeteer for headless browser automation to capture 1080x1920 vertical screenshots from dynamic web pages.
• Built an FFmpeg-based video slideshow generation pipeline with configurable slide duration and transitions.
• Implemented Cloudinary integration for temporary video storage during the Instagram upload workflow.
• Created an automated cleanup system to manage disk space and prevent storage overflow.
CONTRIBUTIONS
• Integrated Puppeteer for headless browser automation to capture 1080x1920 vertical screenshots from dynamic web pages.
• Built an FFmpeg-based video slideshow generation pipeline with configurable slide duration and transitions.
• Implemented Cloudinary integration for temporary video storage during the Instagram upload workflow.
• Created an automated cleanup system to manage disk space and prevent storage overflow.
Multi-tenant AI Knowledge Platform
CONTRIBUTIONS
• Implemented full multi-domain tenant enforcement in a FastAPI back end and comprehensive routing/CORS/auth test suites, bringing feature completion to roughly 89% and 100% test coverage for the epic.
• Authored the domain cutover plan and automation to move prod traffic from demo.sapienceai.co to pilot.sapienceai.co (GCP URL maps, SSL, DNS, Cloud Build bucket swap), including interactive migration/verification scripts and quick-start/rollback playbooks.
• Designed and documented Vertex AI Data Store–based RAG pipeline with Dialogflow CX agents, Firestore metadata, and GCS ingestion, and provided end-to-end API/dataflow guidance for grounded chat responses.
• Conducted end-to-end A2A protocol review across the front end, back end, shared library, and membership agent, surfacing nginx timeout bugs, unused direct-connect path, SSE format gaps, and session/TTL consistency; produced remediation recommendations for low-latency agent streaming.
• Built a secure local developer experience: HTTPS nginx reverse proxy, Docker Compose orchestration, self-signed cert automation, and env templates for both services, enabling hot-reload workflow with a single docker-compose up.
• Implemented full multi-domain tenant enforcement in a FastAPI back end and comprehensive routing/CORS/auth test suites, bringing feature completion to roughly 89% and 100% test coverage for the epic.
• Authored the domain cutover plan and automation to move prod traffic from demo.sapienceai.co to pilot.sapienceai.co (GCP URL maps, SSL, DNS, Cloud Build bucket swap), including interactive migration/verification scripts and quick-start/rollback playbooks.
• Designed and documented Vertex AI Data Store–based RAG pipeline with Dialogflow CX agents, Firestore metadata, and GCS ingestion, and provided end-to-end API/dataflow guidance for grounded chat responses.
• Conducted end-to-end A2A protocol review across the front end, back end, shared library, and membership agent, surfacing nginx timeout bugs, unused direct-connect path, SSE format gaps, and session/TTL consistency; produced remediation recommendations for low-latency agent streaming.
• Built a secure local developer experience: HTTPS nginx reverse proxy, Docker Compose orchestration, self-signed cert automation, and env templates for both services, enabling hot-reload workflow with a single docker-compose up.
Customizable LLM-powered PDF Data Extraction
CONTRIBUTIONS
• Built a FastAPI and PostgreSQL service that ingests Rent Comparability Study PDFs, runs a retrieval‑augmented extraction pipeline, and serves results via a REST API fronted by nginx; React/Vite UI consumes the API and Docker Compose runs the whole stack (back-end, front-end, DB, proxy).
• Supported authenticated, code‑gated user onboarding, cached per‑document PDF/embedding storage, and exported JSON/Excel outputs for HUD RCS fields.
• Designed the product to support ever-changing field requirements and incoming document types.
• Built a FastAPI and PostgreSQL service that ingests Rent Comparability Study PDFs, runs a retrieval‑augmented extraction pipeline, and serves results via a REST API fronted by nginx; React/Vite UI consumes the API and Docker Compose runs the whole stack (back-end, front-end, DB, proxy).
• Supported authenticated, code‑gated user onboarding, cached per‑document PDF/embedding storage, and exported JSON/Excel outputs for HUD RCS fields.
• Designed the product to support ever-changing field requirements and incoming document types.
Principal Engineering of Machine Learning/AI Startup
CONTRIBUTIONS
• Architected and shipped the Workflows v2 Python SDK, letting teams compose DAG-based tasks and configs, run them locally for dev or distribute across Celery/Redis via Jetstream for production-grade ML/document workflows (Python 3, Pydantic, msgpack, Docker).
• Led Jetstream evolution into the platform’s distributed task runner—hardening Celery configs, health checks, heartbeats, msgpack serialization, and Redis/RabbitMQ tuning to keep high-throughput microservices reliable at scale.
• Built the Indico platform FastAPI module set (auth, cookie signing, DB connectors, logging, testing harnesses) so new services inherit secure JWT flows, signed cookies, pooled database access, and uniform observability out of the box.
• Delivered the Workbench (“Gallery”) service: a FastAPI and PostgreSQL microservice for managing versioned field blueprints with tagging, search, bulk import/export, and audit trails—standardizing ML data schemas across apps.
• Drove cloud-native practices across services (Poetry/uv for deps, Docker Compose for local stacks, pytest suites with fixtures) to keep dozens of microservices production-ready and easily reproducible.
• Architected and shipped the Workflows v2 Python SDK, letting teams compose DAG-based tasks and configs, run them locally for dev or distribute across Celery/Redis via Jetstream for production-grade ML/document workflows (Python 3, Pydantic, msgpack, Docker).
• Led Jetstream evolution into the platform’s distributed task runner—hardening Celery configs, health checks, heartbeats, msgpack serialization, and Redis/RabbitMQ tuning to keep high-throughput microservices reliable at scale.
• Built the Indico platform FastAPI module set (auth, cookie signing, DB connectors, logging, testing harnesses) so new services inherit secure JWT flows, signed cookies, pooled database access, and uniform observability out of the box.
• Delivered the Workbench (“Gallery”) service: a FastAPI and PostgreSQL microservice for managing versioned field blueprints with tagging, search, bulk import/export, and audit trails—standardizing ML data schemas across apps.
• Drove cloud-native practices across services (Poetry/uv for deps, Docker Compose for local stacks, pytest suites with fixtures) to keep dozens of microservices production-ready and easily reproducible.
Dealers Hobbyist Card Social Marketplace
CONTRIBUTIONS
• Built HobbyBox, a mobile and web platform for trading-card collectors to discover shows, follow dealers, chat in event rooms, and share inventory via public profiles.
• Led a FastAPI back end (api-server) that serves cards, events, trades, search, notifications, and analytics, with auth, caching, and pagination baked in.
• Designed an S3/SQS-driven card-upload pipeline that hands off images to ML services (YOLOv9 detection, PaddleOCR extraction, verification) to auto-create PSA slab entries and keep status webhooks in sync.
• Shipped the React Native/Expo app (front-end/hobby-box-app) with NativeWind UI, OTA release flow, and CometChat-powered event group chats; paired it with a TanStack Router/Tailwind web experience (hb-web) for shareable profiles.
• Added supporting services and Lambdas for price comps, certification lookups, event sync, push notifications, and email campaigns to keep collectors engaged across channels.
• Built HobbyBox, a mobile and web platform for trading-card collectors to discover shows, follow dealers, chat in event rooms, and share inventory via public profiles.
• Led a FastAPI back end (api-server) that serves cards, events, trades, search, notifications, and analytics, with auth, caching, and pagination baked in.
• Designed an S3/SQS-driven card-upload pipeline that hands off images to ML services (YOLOv9 detection, PaddleOCR extraction, verification) to auto-create PSA slab entries and keep status webhooks in sync.
• Shipped the React Native/Expo app (front-end/hobby-box-app) with NativeWind UI, OTA release flow, and CometChat-powered event group chats; paired it with a TanStack Router/Tailwind web experience (hb-web) for shareable profiles.
• Added supporting services and Lambdas for price comps, certification lookups, event sync, push notifications, and email campaigns to keep collectors engaged across channels.
Education
2011 - 2015
Bachelor of Science Degree in Engineering: Computing
Olin College of Engineering - Needham, MA, USA
Skills
Libraries/APIs
SQLAlchemy, NumPy, Google APIs, Pandas, OpenAI API, TensorFlow, Google Maps API, Facebook API, Google API, Facebook Open Graph API, Google Sheets API, React, ZeroMQ, Scikit-learn, PyQt 5, Python Asyncio, Camera API, Google Cloud API, Node.js, Instagram API
Tools
Docker Compose, Celery, Claude, Claude Code, Amazon Elastic Container Service (ECS), Google Compute Engine (GCE), Android Studio, RedBeat, Astro, Terraform, Helm, RabbitMQ, Expo, Amazon EKS
Languages
SQL, R, Python, Python 3, Java 8, JavaScript, Regex
Paradigms
DevOps, Object-oriented Programming (OOP), Agile Software Development, Responsive, Microservices, Automation
Platforms
Amazon Web Services (AWS), Docker, Google Cloud Platform (GCP), Azure, Android, MacOS, Ubuntu, AWS Lambda, Microsoft, Cloud Run, Kubernetes
Storage
Amazon S3 (AWS S3), Redis, PostgreSQL, RethinkDB, MongoDB, Azure Cloud Services
Frameworks
LangGraph, Android SDK, Selenium, Flask, Django, React Native
Other
APIs, Software Design, Architecture, Async/Await, Containerization, Artificial Intelligence (AI), Cloud, Full-stack, System Architecture, API Integration, Tornado, Data Scraping, Distributed Systems, Machine Learning, AI Architecture, Technical Leadership, Machine Learning Operations (MLOps), Engineering Management, Anthropic, Content, COM, Poetry, SDKs, HTTP Server, FastAPI, CI/CD Pipelines, API Design, Optical Character Recognition (OCR), OpenAI, Supabase, Modal, OpenAI GPT-4 API, Natural Language Processing (NLP), PDF, Analytics, Instrumentation, Gemini, Vertex, Large Language Models (LLMs)
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