# Lei L.

> Senior Software Engineer | React, JavaScript, .NET | Cloud & Medical Imaging (HL7, FHIR, DICOM, Cornerstone3D) | 7+ YOE | TN Eligible

Location: San Francisco, California, United States
Profile: https://flows.cv/leil

Software Engineer | MedTech | Health IT | Medical Imaging



I am a Software Engineer with 7+ years of experience building cloud-native, browser-based medical imaging solutions that streamline radiology workflows and enhance diagnostic access. I specialize in scalable DICOM/RIS/PACS workflows, advanced image analysis tools, and modern web technologies like React, Node.js, and .NET.



My experience spans backend systems, microservices, and high-performance data pipelines, with expertise in DICOMweb/FHIR APIs and Azure cloud services. I’m passionate about leveraging MedTech to improve clinical efficiency, system reliability, and patient care.

## Work Experience
### Software Engineer @ RamSoft
Jan 2020 – Present | Toronto, ON
Medical Imaging & Clinical Workflows:

- Core Full-Stack Developer on a cloud-native RIS/PACS platform, building a zero-footprint web DICOM Image Viewer using React and Cornerstone3D for radiology diagnostic workflows.
- Ported complex clinical workflows, such as Series Splitter and Mammography Sorting, from a legacy Delphi desktop app
- Developed advanced diagnostic tools including ROI/SUV analysis and Automatic Window Leveling 

Performance & Scalability:
- Optimized large-study performance through progressive retrieval, Web Worker caching, and prefetching, improving load time and reducing memory usage.

System Architecture & Backend Services:
- Migrated Image Viewer from v1 → v4, redesigning architecture for performance and long-term maintainability.    
- Architected a Node.js microservice for generating DICOM Structured Reports (SR) from raw measurement data, closing a key gap in the clinical study export pipeline.
- Built DICOMweb and FHIR APIs using .NET 8 to support clinical data pipelines, leveraging Azure services including Functions, Event Grid, Blob Storage, Cosmos DB, Key Vault, and MS SQL.


Testing & Engineering Practices:
- Resolved P1/P2 production incidents and conducted root cause analysis (RCA) and post-mortems that improved system reliability and reduced recurring failures.
- Developed automated tests including unit, integration, and Playwright-based E2E tests for critical Image Viewer workflows, improving system reliability and release confidence.
- Mentored junior developers and reviewed frontend PRs, improving team code quality and technical decisions.

### Web Developer @ Lowell Academy
Jan 2018 – Jan 2019 | Toronto, Ontario, Canada
Technology: C#, .NET 4.6, MVC 5, Web API; MS SQL; AWS; Bootstrap; JavaScript, AJAX, JSON;
•Rebuilt official website UI entirely and optimized UX.
•Created a Content Management System built in .NET stack
•Built RESTful Services with ASP.NET Web API to fetch, add, edit and delete data from client side
•Implemented various functions including Calendar, Multi-language, File Upload, Form Submission, Email Alert, Instagram Sync and so forth.
•Deployed and maintained the website on AWS (Elastic Beanstalk, S3).
•Instructed ICSU3 and ICS4U courses by Java

### Full Stack Developer @ WCG: The IT Exchange, Inc.
Jan 2018 – Jan 2018 | Toronto, Canada Area
Technology: C#, .NET, MS SQL, XML, XSL, XPATH, Bootstrap, JavaScript, jQuery, AJAX, JSON, REST API, AWS
•Developed web sites for logistics projects and internal framework built in .Net stack.
•Create and design customized reports screen based on client requirements.
•Built a monitoring system tracking each internal server status.
•Implemented data visualization using Google Charts library 
•Provided clients with training and technical support on the final products.

### iOS Developer @ Somoplay
Jan 2017 – Jan 2017 | Toronto, Canada Area
Technology: Swift 3, MVVM, Realm Database, REST APIs, JSON, Facebook API, Google Places & Maps API
•Reactive Programming with RxSwift, RxCocoa and RxGesture
•Fetched and parsed JSON data using REST API as well as processed it with Model Objects
•Developed social network Account Login and remote Push Notification using Firebase
•Worked with Google Map API to locate and relocate place and indicate information
•Created animations to improve user experience
•Built UI and performed Seque programmatically
•Implemented video player and video controls


## Education
### Master's Degree in Computer Science
University of Windsor

### Bachelor's degree in Computer Science
Yunnan Normal University


## Contact & Social
- LinkedIn: https://linkedin.com/in/lei-liu-1025

---
Source: https://flows.cv/leil
JSON Resume: https://flows.cv/leil/resume.json
Last updated: 2026-04-11