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Colin Li

Experience
Data Engineer
Feb. 2025 -- Present
Mastercard Arlington, VA
  • Designing and maintaining large-scale ETL pipelines on on-prem systems, integrating and transforming hundreds of terabytes of data from global enterprise clients using Microsoft SQL Server and Python.
  • Optimizing processing workflows for several high-volume clients, reducing multi-hour data processing jobs to under 1 hour.
  • Developing a VS Code extension adopted by 30+ engineers to provide SQL-query shortcuts and automation, improving developer productivity and reducing repetitive query-writing time.
Software Engineering Intern
Jul. 2023 -- Dec. 2024
Evil Geniuses Los Angeles, CA
  • Built machine learning models used by coaches and management to evaluate over 1,000 professional players and support roster selection decisions.
  • Created a computer vision system (YOLOv5 + PyTorch) to detect logo placement and viewership across broadcast footage, providing analytics used in sponsorship negotiations and contributing to a $75,000 increase in annual sponsorship revenue.
  • Designed automated ETL pipelines using AWS Lambda, S3, and EC2 to ingest and normalize 2 TB/month of analytics data from 4 APIs into PostgreSQL, eliminating 10+ hours/week of manual data processing for staff.
Founder
Jan. 2021 -- Dec. 2023
Macrohard LLC Chicago, IL
  • Built a real-time predictive analytics model for competitive gaming broadcasts, achieving 4% higher accuracy than all publicly available baselines and deployed in live productions.
  • Led a 7-person team across engineering, design, and operations; grew product revenue to $15,000 through sales and client partnerships.
Projects
Explorer | Node.js, React, Expo, MySQL
Sept. 2023 -- Present
  • Building an end-to-end platform (React web + Expo mobile) that authenticates users, stores location data, and visualizes their travel history across time.
  • Architecting a MySQL schema and data-ingestion pipeline for 30,000+ GPS points per user; optimized geospatial queries, reducing page load from 30s → 2s.
  • Implementing social features including friend connections and selective location-sharing, with secure token-based authentication and permission controls.
FearlessDraft.net | Node.js, Express, MongoDB
Sept. 2024 -- Jan. 2025
  • Developed a scalable real-time game simulation platform with 11,000 monthly users and 100–500 simulations per day, resulting in a contract with Riot Games to create a custom enterprise version.
  • Implemented a performant Node.js + MongoDB architecture supporting concurrent game sessions with low-latency updates over WebSockets.
Self-Driving RC Car | OpenCV, Jetson Nano, Flask
Sept. 2024 -- Dec. 2024
  • Engineered an autonomous RC car capable of completing a 500 m route with 2 m positional accuracy using GPS, stereo depth cameras, and LiDAR.
Technical Skills
  • Languages:Python, SQL, JavaScript, TypeScript, C/C++, Java, HTML/CSS
  • Technologies:Node.js, React, Express.js, Flask, AWS (S3, Lambda, EC2), PostgreSQL, MySQL, MongoDB, Redis, Socket.IO, OpenCV, YOLO, TensorFlow, PyTorch, Pandas, NumPy
  • Specialties:ETL Pipelines, Distributed Systems, Computer Vision, Data Modeling, Database Optimization, REST APIs, Cloud Architecture, AI/LLM Integration
Education
University of California, San Diego
Sept. 2021 -- Dec. 2024
B.S. Computer Engineering San Diego, CA

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