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Senior Full-Stack Engineer with 10+ years of experience building scalable web platforms across insurance, fintech, SaaS, healthcare, and enterprise environments. Strong background in React, Next.js, TypeScript, Node.js, GraphQL, Java/Spring Boot, Python, FastAPI, PostgreSQL, Redis, AWS, Docker, Kubernetes, and Terraform. Experienced in modernizing enterprise workflows, building real-time product interfaces, improving release reliability, and adding AI-enabled capabilities to existing business systems. Recently focused on practical AI product development, including LLM integrations, RAG-style retrieval workflows, embeddings, vector search, prompt design, and structured AI outputs for internal workflow automation.…Senior Full-Stack Engineer with 10+ years of experience building scalable web platforms across insurance, fintech, SaaS, healthcare, and enterprise environments. Strong background in React, Next.js, TypeScript, Node.js, GraphQL, Java/Spring Boot, Python, FastAPI, PostgreSQL, Redis, AWS, Docker, Kubernetes, and Terraform. Experienced in modernizing enterprise workflows, building real-time product interfaces, improving release reliability, and adding AI-enabled capabilities to existing business systems. Recently focused on practical AI product development, including LLM integrations, RAG-style retrieval workflows, embeddings, vector search, prompt design, and structured AI outputs for internal workflow automation.

William Xin

Full Stack Developer, Back-End Developer, Front-End Developer, +2

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Senior Full-Stack Engineer with 10+ years of experience building scalable web platforms across insurance, fintech, SaaS, healthcare, and enterprise environments. Strong background in React, Next.js, TypeScript, Node.js, GraphQL, Java/Spring Boot, Python, FastAPI, PostgreSQL, Redis, AWS, Docker, Kubernetes, and Terraform. Experienced in modernizing enterprise workflows, building real-time product interfaces, improving release reliability, and adding AI-enabled capabilities to existing business systems. Recently focused on practical AI product development, including LLM integrations, RAG-style retrieval workflows, embeddings, vector search, prompt design, and structured AI outputs for internal workflow automation.…Senior Full-Stack Engineer with 10+ years of experience building scalable web platforms across insurance, fintech, SaaS, healthcare, and enterprise environments. Strong background in React, Next.js, TypeScript, Node.js, GraphQL, Java/Spring Boot, Python, FastAPI, PostgreSQL, Redis, AWS, Docker, Kubernetes, and Terraform. Experienced in modernizing enterprise workflows, building real-time product interfaces, improving release reliability, and adding AI-enabled capabilities to existing business systems. Recently focused on practical AI product development, including LLM integrations, RAG-style retrieval workflows, embeddings, vector search, prompt design, and structured AI outputs for internal workflow automation.

Available to hire

Senior Full-Stack Engineer with 10+ years of experience building scalable web platforms across insurance, fintech, SaaS, healthcare, and enterprise environments. Strong background in React, Next.js, TypeScript, Node.js, GraphQL, Java/Spring Boot, Python, FastAPI, PostgreSQL, Redis, AWS, Docker, Kubernetes, and Terraform. Experienced in modernizing enterprise workflows, building real-time product interfaces, improving release reliability, and adding AI-enabled capabilities to existing business systems. Recently focused on practical AI product development, including LLM integrations, RAG-style retrieval workflows, embeddings, vector search, prompt design, and structured AI outputs for internal workflow automation.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Work Experience

Senior Software Engineer at Liberty Mutual Insurance

April 1, 2022 - Present

Led development of internal risk and claims workflow platforms used by operations and insurance teams. Built React-based workflow interfaces and Java/Spring Boot APIs for business-critical enterprise processes, modernizing legacy workflows by separating high-change UI flows, backend business rules, and deployment concerns. Implemented dynamic form and case-review experiences with configurable intake flows, validation logic, and role-based views. Designed Spring Boot endpoints for case retrieval, status transitions, and user permissions. Added a separate Python/FastAPI service layer for AI-assisted workflow experiments, including document retrieval, prompt orchestration, and structured JSON outputs integrated into case-review interfaces. Built retrieval-assisted features using embeddings and vector-search patterns with enterprise constraints (access control, auditability, latency, observability, and fallback behavior). Containerized services with Docker and supported Kubernetes deployme

Senior Full Stack Engineer at JoY

February 1, 2020 - April 30, 2022

Delivered customer-facing SaaS features for wedding planning and guest coordination using React, Next.js, TypeScript, Node.js, GraphQL, PostgreSQL, and Docker-based workflows. Built GraphQL-backed Node.js services for RSVP management, guest check-in, registry synchronization, and collaboration workflows. Reduced server latency by 60% for real-time RSVP and guest coordination through API optimization, improved data access patterns, and clearer service boundaries. Developed high-utility frontend experiences with Next.js rendering strategies and reusable React components, and improved implementation speed and consistency with reusable TypeScript component patterns and Storybook documentation. Increased scalability by modularizing collaboration features and reducing coupling between frontend screens and backend logic. Improved frontend performance and user-flow clarity to support responsive customer journeys, contributing across product definition, API design, and release execution.

Lead Frontend Engineer at dYdX

September 1, 2017 - December 31, 2019

Built a high-throughput real-time trading interface using React, Redux, and WebSockets, with data-rich UI patterns for fast financial workflows. Delivered millisecond-sensitive market updates and responsive interaction states for users monitoring live asset and execution changes. Developed advanced charting and information-dense dashboards to turn streaming market data into clear product experiences. Improved frontend responsiveness through component performance tuning, bundle optimization, and targeted rendering refinements for high-concurrency usage. Integrated frontend workflows with backend services and APIs to maintain reliable access to frequently changing data. Partnered with cross-functional stakeholders to balance UX clarity and user trust with low-latency delivery.

Full Stack Engineer at Solv

June 1, 2014 - July 31, 2017

Built healthcare workflow systems using structured backend services and PostgreSQL, focusing on secure business logic for scheduling, intake, and verification processes. Integrated Twilio-based appointment notifications and reminders, helping reduce no-show rates by 35%. Supported production reliability, data integrity, and operational workflows in a compliance-sensitive healthcare environment with high expectations for correctness. Improved secure application behavior with role-based access controls, encrypted data handling, audit-friendly system flows, and reliable user-permission checks. Built operational dashboards for clinic administrators using React and GraphQL/Apollo-style data access patterns, including real-time workflow visibility. Collaborated across frontend, backend, and data concerns to improve maintainability and reduce friction in business-critical healthcare journeys.

Frontend Developer at IBM

April 1, 2012 - March 31, 2014

Built enterprise UI features for banking and insurance systems using JavaScript, AngularJS/jQuery, HTML, and CSS, integrating with Java/Spring APIs. Developed responsive UI components and form-heavy enterprise screens, improving usability and layout consistency across browsers. Assisted with migration of legacy JSP-based pages toward single-page application patterns to improve maintainability and page-load behavior.