Open to opportunities

Sean Chen

@seanchen3

Senior full-stack and AI engineer building production web and mobile systems, integrating LLMs on cloud-native architectures.

Ireland

Message

What I'm looking for

I’m looking for a product-minded team where I can own end-to-end features and ship reliable, performance-optimized systems—using React/Node and integrating AI/LLM (OpenAI, LangChain, RAG) into real production workflows.

I’m a Senior Full-Stack and AI Engineer with 8 years of experience designing, building, and scaling web and mobile applications for fast-growing startups and product companies. I’m known for end-to-end ownership—system design, implementation, testing, and DevOps—while collaborating closely with product, data, and design teams in distributed, remote-first environments.

I bring proven expertise in React, Next.js, TypeScript, Node.js, and Python, alongside strong backend API design and cloud-native architectures on AWS, GCP, and Azure. I focus on performance optimization and reliable delivery across complex, high-traffic systems.

Most recently, I led AI integrations for an AI-powered marketplace platform—driving AI-driven search, recommendation, and ranking. I partnered with data science and product to run A/B experiments, and I optimized backend APIs and database access patterns (PostgreSQL, Redis), reducing average page load times and improving stability during peak traffic.

Before that, I built and shipped scalable AI APIs for an enterprise AI SaaS platform, designing REST and GraphQL APIs and productionizing OpenAI-based models with monitoring, error handling, and performance tuning. Earlier, I delivered LLM-based automation and RAG workflows for AI marketing products, reducing manual workload for global teams.

Experience

Work history, roles, and key accomplishments

Senior Full-Stack Engineer

Motorway

Mar 2023 - Feb 2026 (2 years 11 months)

Led AI-driven search, recommendation, and ranking on a high-traffic marketplace, improving search relevance and conversion while reducing core-flow latency. Owned end-to-end feature delivery and optimized PostgreSQL/Redis backend APIs and release reliability using React, Next.js, Node.js, GraphQL, Auth0, and Stripe on GCP/Vercel.

React Next.js PostgreSQL Redis GraphQL Auth0 Stripe GCP Vercel

Senior Software Engineer - AI

Parloa

Jan 2021 - Feb 2023 (2 years 1 month)

Built end-to-end features for a B2B AI SaaS platform, enabling enterprise customers to automate and scale interactions using ML-driven insights. Designed REST/GraphQL APIs for AI outputs, productionized OpenAI custom models with monitoring and performance tuning, and improved CI/CD and observability to reduce deployment time and production incidents.

React TypeScript fastAPI OpenAI PostgreSQL MongoDB REST APIs GraphQL CI CD

Senior Full-Stack Engineer - AI

SilverPush

Jun 2019 - Dec 2020 (1 year 6 months)

Shipped AI-powered marketing and messaging features by integrating LLM-based automation and RAG workflows to reduce manual marketing effort. Built scalable multi-tenant SaaS APIs and data models and delivered production releases across EU and Asia time zones using React, Node.js, PHP, PostgreSQL/MongoDB, AWS, and Docker.

React PHP PostgreSQL MongoDB AWS Docker RAG LLM Multi Tenant SaaS Models

Full-Stack Engineer - E-commerce

Profitero

Oct 2017 - May 2019 (1 year 7 months)

Developed merchant-facing dashboards and analytics views to help online retailers track sales, funnels, and performance metrics. Improved Node.js/PostgreSQL backend performance and reliability under high traffic and supported frequent agile delivery using React, Elasticsearch, and AWS.

React JavaScript PostgreSQL Elasticsearch AWS Dashboard Development API Development