Senior Software Engineer
Winston Yeung
Senior Full Stack Software Engineer
I build reliable software for complex workflows across SaaS, healthcare, fintech, legal technology, and cloud platforms.
Backend foundations → APIs and integrations → cloud and AI-enabled systems
About
Software engineer with 10+ years building scalable full-stack web applications, SaaS platforms, and enterprise systems across design technology, healthcare, payments, and legal software—with a focus on secure, maintainable architecture, responsive UI/UX, automated testing, and CI/CD.
Hands-on across TypeScript/JavaScript, React, Next.js, Python, C#/.NET, REST APIs, WebSockets, SQL/NoSQL, Azure, and AWS. Experienced with microservices, AI/LLM integrations, performance optimization, mentoring, and delivering reliable cloud software from design through production.
Selected Work
Connected Design and Commerce Workflows
Application features, backend services, APIs, and cloud integrations connecting configuration, planning, quoting, and ordering into reliable multi-tenant design-to-commerce workflows.
Context: Design Flex and 3CAD product context
Privacy-Aware Clinical Assessments
Full-stack posture and movement assessment workflows—image capture, analysis, history, progress comparison, reporting—with privacy-aware handling of health-related data.
Context: PostureScreen and RemoteScreen ecosystem
Secure Merchant and Payment Operations
Backend APIs, partner integrations, validation, and operational tooling for merchant and payment workflows where correctness, auditability, and production stability are critical.
Cloud Legal Practice Workflows
SaaS product and backend features across matters, calendaring, billing, trust, documents, and integrations for cloud legal practice management.
Context: Clio Manage
Experience
Senior Software Engineer · Cyncly
Architected full-stack capabilities for cloud design and business workflow software—TypeScript, React, Next.js, and MUI on the frontend with C#/.NET and ASP.NET Core APIs—plus modular services, WebSockets/Redis, Docker/Kubernetes on Azure and AWS, and mentoring across distributed Agile teams.
Senior Software Developer · PostureCo
Built posture assessment and healthcare software with React, Next.js, and Python/FastAPI—practitioner dashboards, AI/ML and LLM-backed analysis workflows, real-time WebSockets updates, and secure data layers across PostgreSQL, MongoDB, and Firebase.
Software Developer · Nuvei
Delivered full-stack payment platform features—merchant interfaces with TypeScript and AngularJS, Java/Node.js transaction services, real-time status via WebSockets, and secure JWT/OAuth patterns across high-volume PostgreSQL and MySQL workloads.
Software Developer · Clio
Built customer-facing features for legal practice management SaaS—AngularJS modules, RESTful API integrations, Node.js/Express services, and PostgreSQL-backed workflows for matters, contacts, documents, and client data.
Capabilities
Backend services and APIs
Node.js, NestJS, .NET, FastAPI · REST, GraphQL · microservices
Cloud and platform engineering
Azure, AWS, GCP · Docker, Kubernetes · CI/CD · cloud deployment
Full stack product development
React, Next.js, TypeScript · Python, C# · end-to-end ownership
Enterprise integrations
JWT, OAuth · partner APIs · WebSockets · Redis · sync workflows
Secure and reliable data workflows
PostgreSQL, MongoDB, MySQL · Redis · secure coding · GDPR practices
AI-enabled product engineering
AI/ML integrations · LLM APIs · SaaS · enterprise systems
Engineering Principles
Understand the workflow before designing the system
Treat reliability as a product feature
Prefer maintainable systems over clever complexity
Own the outcome, not only the ticket
B.Sc. Computer Science
University of Toronto
Contact
Let's build something dependable.
I'm open to senior software engineering roles across full stack, backend, cloud applications, platform engineering, DevSecOps-focused development, and AI-enabled product engineering.