Leng Zhang

Software Dev Engineer

Amazon•  June 2021 - March 2023

Developed a robust reporting system for aggregating and analyzing web crawler activity data, providing comprehensive insights into web trends, indexing, and data collection. This versatile internal tool benefits both my team and customers for tracking and understanding crawler activities. - Architected the system using AWS API Gateway and AWS Lambda to efficiently route back-end APIs and React.js assets stored in an S3 bucket. - Developed the reporting dashboard with React.js and Polaris UI library, in alignment with AWS UI style guidelines, enabling customers to effortlessly access daily or weekly report data based on their selected time range. - Implemented an AWS Lambda function in TypeScript to efficiently route customer requests through AWS API Gateway to both the back-end APIs and the static web assets of the reporting dashboard. - Integrated the TypeScript CDK with the reporting dashboard and the router Lambda function to automate the deployment of AWS components like API Gateway, Lambda function, Route 53, Certificate Manager, and Reac.js application assets to the S3 bucket. Technologies: React.js, Polaris Ui, TypeScript, AWS Lambda, API Gateway, Route 53, AWS Certificate Manager, AWS S3 The collection feature in the reporting system enables customers to generate a report for a single crawl, reducing the time required by 90% when customers request detailed crawler information. - Implemented the collection feature using AWS Lambda in Java, which aggregates data from DynamoDB tables and maintains real-time progress updates in an S3 object. - Integrated the reporting system with the collection feature, allowing customers to upload crawl information through the reporting dashboard, triggering the AWS Lambda function for generating the collection report while continuously monitoring the S3 object for real-time progress updates. Technologies: React.js, Java, AWS Lambda, DynamoDB, AWS S3 An automated metrics system that is triggered daily and weekly by EventBridge rules, which aggregates summaries of crawler activities, expenses, and resource utilization into a unified report, and stored within an S3 bucket. - Implemented the metrics system using AWS Lambda in Java, enabling the aggregation of data from various services into a single Parquet file stored in an S3 bucket. - Integrated the CDK with the automated metrics system by incorporating EventBridge rules and deploying the AWS Lambda function. - Integrated the reporting system with the metrics system to enable real-time monitoring of generation progress and Parquet file downloads. Technologies: Java, AWS Lambda, AWS S3, EventBridge

Software Engineer Full Stack

Fillstorship•  June 2020 - August 2020

A React.js application assists customers in efficiently managing the fulfillment, warehousing, and distribution of their e-commerce order processing. - Implemented payment UI and APIs using the authorize.net SDK, ensuring SAQ-A level PCI compliance for secure payment submission and management. - Developed reusable React.js hooks and APIs for efficiently uploading files to AWS S3 in a queue, facilitating the attachment of files to e-commerce orders. - Collaborated closely with the team to enhance both the user interface and application logic, ensuring improved overall performance and user experience. Technologies: TypeScript, React.js, AWS S3, authorize.net

Software Engineer Front-end

AITmed Telemedicine•  January 2019 - March 2020

A React.js-based patient portal enabling patients to schedule instant remote appointments with doctors, manage medical documents, and access online specialist referrals, ensuring a seamless and convenient healthcare experience. - Led the patient portal’s development, collaborating closely with both the product manager and UX designers, and with the concentration on designing communication features and workflows for patients and doctors. - Created a responsive web application with React.js, offering telemedicine services that enable patients to consult efficiently and promptly with doctors remotely. - Revamped the doctor portal user interface, applying responsive web design principles using the Material-UI library. - Developed reusable React.js hooks for input field components using the react-final-form library to minimize code duplication and enhance form performance. - Created reusable React.js hooks using the OpenTok APIs to streamline video communication logic. - Migrated the React.js doctor portal application from JavaScript to TypeScript, resulting in improved code quality and introducing static type-checking. - Developed an internal SDK NPM package to enable seamless communication between a GRPC server and the application layer. - Implemented unit test with Jest for both the patient and doctor portal, emphasizing code maintainability and reliability. Technologies: TypeScript, JavaScript, React.js, Material-UI, OpenTok, Jest