Designed a full stack project using MERN and Redux for users to track their LeetCode progress, and Material UI for a visually appealing and responsive user interface.

Constructed a robust token-based authentication system using MongoDB for data storage, bcrypt for password hashing, JWT (JSON Web Tokens) and localStorage for storing the authentication token on the client-side.

Improved Lighthouse performance from 52 to 99 by implementing optimization techniques, including lazy load, text compression and minification of JavaScript files.

Implemented an existing API into multiple RESTful micro servers and used PostgreSQL to store millions of product information with ETL process.

Reduced response time from 2000 ms to 2 ms through adding indexes and improving queries, and handled local stress tests using K6 under 1000 requests per second, significantly minimizing the latency.

Deployed server and database with Docker on AWS EC2 instance, and scaled the application with Nginx and loader.io to handle over 2000 requests per second under 1% error rate.

Built a functional e-commerce product page (overview and product details) with React and raw CSS, and over 80% Jest and React Testing Library coverage.

Deployed on AWS EC2 instance and tested performance with Google Lighthouse.

Implemented Agile methodology with Trello tickets, standups, retrospectives and git workflow.