Open to opportunities

David Liu

@davidliu2

Message

Senior C# backend engineer building scalable AI-powered microservices with REST APIs and gRPC.

United States

Message

What I'm looking for

I’m looking for a senior C# backend role to build scalable microservices and AI-powered systems, own API and performance improvements, and mentor teams in fast-moving Agile environments.

I’m a Senior Software Engineer (C# Backend) with 8+ years of experience building scalable, AI-powered backend systems for products serving hundreds of millions of users. I’ve architected high-throughput microservices at Snap Inc and Amazon, with deep expertise in C# and Python, REST APIs, and gRPC—often improving throughput and reliability under peak load.

My work centers on AI/ML integrations (including GenAI and vector database indexing with pgvector) and production-ready performance using PostgreSQL and Redis. I also enjoy raising team quality—mentoring junior engineers, driving correctness and performance through code reviews, and delivering reliable CI/CD and deployments across Kubernetes, Docker, and cloud infrastructure.

Experience

Work history, roles, and key accomplishments

Current

Senior Software Engineer

Current

Snap Inc

Jan 2022 - Present (4 years 5 months)

Architected and led C#/.NET backend development for Snapchat AR platform services, building microservices that supported Lens Studio tooling, AR content delivery, and real-time collaboration for millions of daily active users. Built OpenAI- and pgvector-powered AI recommendation backends, improved internal API throughput with gRPC, and deployed Kubernetes/AWS microservices with 90%+ test coverage

C++ASP.NET Core gRPC SignalR OAUTH2 PostgreSQL Redis Kubernetes AWS Pgvector

Software Engineer II

Amazon

Jul 2017 - Jan 2022 (4 years 6 months)

Designed and operated scalable ASP.NET Core RESTful backend services for a multi-vendor marketplace, reducing checkout latency by 35% through PostgreSQL query optimization and Redis caching. Implemented OAuth2 with RBAC, integrated third-party payment processing, and built Kafka-driven event pipelines to decouple order, inventory, and notifications.

C++ASP.NET Core REST APIs OAUTH2 RBAC PostgreSQL Redis Kafka Docker

Software Developer Internship

Ericsson

Sep 2015 - Apr 2016 (7 months)

Developed and optimized dynamic, mobile-first UI components for Ericsson’s telecom platform using Vue.js, SCSS, and Bootstrap. Improved accessibility compliance by raising platform scores from 60% to over 95% in line with WCAG standards.

Vue.Js SCSS Bootstrap JavaScript Accessibility Responsive UI UI Components Agile Scrum C# Core

Software Developer Internship

Octasic

May 2015 - Aug 2015 (3 months)

Built analytics dashboards for contacts, clients, and prospective clients using AngularJS and supported a C# full-stack development roadmap. Integrated C# backend functionality with AngularJS frontends.

AngularJS C++Full Stack Developer Dashboards Frontend Dashboard Development JavaScript