Senior Software Engineer

YiFan Li

SENIOR SOFTWARE ENGINEER EXPERT IN FULL-STACK, MOBILE &

WEB TECHNOLOGIES

+1-917-***-**** *****.********@*****.*** Redmond, Washington, US

www.linkedin.com/in/yi-fan-pitts

SUMMARY

Senior Full-Stack Engineer with 9+ years of experience building and delivering scalable, distributed web applications across modern cloud environments. Proficient in TypeScript, Java, .NET, React, FastAPI, Azure and AWS, with deep expertise in microservices architecture, API engineering, and CI/CD automation for seamless deployment and reliability. Build systems that balance scalability, developer efficiency and user experience in production-grade environments.

SKILLS

Programming Languages: Python, C#, JAVA, Scala, JavaScript/TypeScript

Frameworks and tools: Django/Flask/FastAPI, .NET, Spring Boot, Spring Cloud, ReactJS/Next.js, Node.js/Express.Js, AngularJS, Akka, Hadoop, Zookeeper, MapReduce, Apache Spark, Azure Synapse, ETCD

Machine Learning Technologies: LangChain, LangGraph, LLm, RAG, Vector Database (Pinecone, FAISS)

Mobile Development: React Native, Flutter

API & Integration: REST APIs, GraphQL, WebSockets, gRPC, RabbitMQ, Kafka

Databases: MySQL, PostgreSQL, MongoDB, DynamoDB, Neo4j, Cassandra, Redis

DevOps & Cloud Tools: Azure, AWS, GCP, Cloudflare, CI/CD tools, Git, Docker, Kubernetes, Terraform, Jenkins, Helm, Prometheus, JMeter, Linux, Splunk

WORK EXPERIENCE

Senior Full Stack Developer, Microsoft Jan 2023 – present

Implementing ReactJS and Redux to create user interfaces and proficient in leading frameworks such as React.js to create high-quality, scalable, and reusable components and front-end solutions. ReactJS was used to build specific components for data manipulation and presentation in the company's standard format.

Used React.js and Redux framework for premade components from NPM and worked with Redux architecture increase website speed, as well as React Flux architecture and Redux form to handle form state in Redux.

Develop and execute all phases of testing with Jasmine, Karma for unit testing, and Protractor for End2End automated testing on both the client and server sides utilizing the Mocha and Chai frameworks.

Implement different Design Patterns including MVVM for WPF and Silverlight applications and used J2EE Design Patterns Session Facade, Aggregated entity for the Middle Tier development and developed EJBS Session and Message-Driven Beans in RAD for handling database access and asynchronous messaging.

Leveraged features of Java 8 such as Default and Static methods in Interfaces, Lambda expressions, StreamAPI, Nashorn JavaScript Engine, IO Enhancements, and the Parallel sort in Arrays.

Played a key role in optimizing search performance, contributing to an 80% increase in speed. This was achieved through a combined effort in fine-tuning Elasticsearch queries and enhancing the search APIs.

Migrated SOAP web service resources to Spring RESTful utilizing the Spring REST API and Spring Boot and created action classes in Struts and developed managers classes using Hibernate, JPA and Strut technologies and implement application-level persistence using Hibernate and Spring.

AI Chatbot Development Contribution: Contributed to the company’s AI chatbot development, working in tandem with the Data team to integrate advanced LLM models, enhancing user interactions and overall functionality.

Involved in creating and maintaining the architecture for a Restful API utilizing Spring Boot to monitor and manage the application in a production environment, as well as integrating Spring Security to validate users.

Implement the Data Access Layer with Spring Data and the Hibernate ORM tool and created a web-application for business reporting, system monitoring and troubleshooting with J2EE and Tomcat.

Established Kubernetes platform AKS with Terraform, network policies, cluster auto scaling rules and GitOps-style deployment.

Delivered full-stack observability Prometheus + OpenTelemetry + Jaeger and testing culture pytest + Playwright + chaos, driving MTTR under 15 min and zero customer incidents in 12 months.

Senior Python Developer, Microsoft Nov 2021 – Jan 2023

Implemented robust data models and ETL frameworks using PySpark and Azure Data Lake Storage, ensuring high data quality, reliability, and compliance across mission-critical analytics workflows.

Leveraged advanced Python features such as asynchronous programming with asyncio, type-safe development using PEP 484 type hints, context managers, decorators, and efficient data processing with generator expressions and iterators to build high-performance backend services.

Implemented Python 3.9+ capabilities, including structural pattern matching, improved dictionary union operations, and optimized multiprocessing through concurrent.futures, enabling cleaner code architecture, reduced complexity, and faster execution across large-scale data workflows.

Developed robust, production-grade systems by integrating Python’s core libraries—dataclasses, functools, itertools, collections, and logging—ensuring maintainable code, improved readability, predictable performance, and enterprise-level reliability across distributed microservices and ETL pipelines.

Orchestrated a microservice architecture facilitating distributed microservices with FastAPI, leveraging Kafka and internal queues for event-driven messaging and reducing average service latency by 30%.

Revamped end-to-end CI/CD pipelines using GitHub Actions and Azure DevOps, resulting in a 150% increase in deployment frequency and a 25% improvement in team efficiency across the engineering organization.

Built SPA Single Page Applications using AngularJS concepts of Components, Directives, Services, Promises, Templating, Dependency Injection, two-way data binding and http with AngularJS interceptors.

Administered SQL databases, ensuring data integrity, performance optimization, and seamless integration with business applications.

Backend Engineer II, Rally Health Jun 2019 – Nov 2021

Refined Proton, a command-line tool facilitating faster service creation and updates; drove a 40% increase in developer velocity and was adopted as the most used CLI tool within 6 months.

Innovated Archimedes, a dependency tracker, which identified and helped resolve the three biggest causes of dependency-related build failures, thus improving build stability and reliability.

Enhanced backend systems with async programming, improving concurrency handling and scalability which overall system performance and stability by 3.5x.

Built advanced React and Angular dashboards in TypeScript to visualize large-scale product and user-flow analytics, delivering smooth performance across 50K+ data points.

Engineered an ASP.NET backend powering real-time monitoring tools that visualized service performance, error trends, and dependency health, reducing investigation time by 60%.

Rectified a critical account auto-refill error, collaborating with over 5 external engineers to prevent erroneous card transactions, and saving the company $100,000 per month previously lost to reimbursements.

Integrated AWS services (S3, Lambda, Aurora) for cloud-native storage and compute scaling while deploying SaltStack for infrastructure automation, leveraging Kubernetes and Docker for seamless container orchestration, and developing robust CI/CD pipelines that reduced deployment time by 40%.

Full Stack developer, Infosol Inc Sep 2017 – May 2019

Discussed, analyzed, and strategized product design with Product Managers, Design Team, and Business Managers.

Created and deployed RESTful API endpoints using NodeJs, ASP.NET, and InfoBurst cached XDC queries on AWS.

Developed and designed web application visualizations using JavaScript frameworks and libraries such as Angular 5/6/7 and React w/ Redux.

Transformed SAP BusinessObjects reports from SAP - Web Intelligence into consumable data for API use for multiple client projects.

Created SAP BusinessObjects dashboards proof of concepts for multiple Business Intelligence clients.

Crafted dashboards and visualization heavy applications using UI and Dashboard frameworks such as Telerik, KendoUI.

Formulated multiple POC web applications with integrated OKTA and Auth0 in React and Angular for multiple clients.

EDUCATION

Master ’s Degree of Information Science

University of Pittsburgh Jun 2017 - May 2019

Bachelor’s Degree of Computer Science

Xidian University Jun 2013 - May 2017

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