Lead Fullstack Engineer (Korea , Seoul)
Our client is a publicly traded global AI product company headquartered in the U.S., building technology that transforms how businesses and users interact by making digital experiences more human, intelligent, and engaging.
The product is a next-generation platform of AI-powered avatar assistants, designed combining advanced AI models with real-time interaction layers and expressive avatar technology, enabling businesses to deliver personalized, conversational experiences across customer touchpoints, at scale and in production environments. The product is already live and proven in the market, deployed globally at scale, with a growing base of customers and expanding commercial traction, actively used by enterprise clients.
We are looking for a Senior Lead Engineer to join the core engineering team in Seoul, Korea, and own the architecture and end-to-end delivery of the company’s core AI product.
This is a critical hands-on role, focused on AI inference optimization, latency reduction, and scalable API design, enabling efficient real-time communication between server and web systems, across complex distributed systems from design to production.
Tech stack includes (approx. 70% backend / 30% frontend) Python (Flask / FastAPI / Litestar), React or Svelte with real-time interactions across Web, Unity, and AI modules via WebSockets and SSE.
The role offers a competitive compensation package, along with a comprehensive set of benefits. You will join a rapidly scaling global AI company and have strong opportunities for career growth, technical ownership, and professional development while contributing directly to a product already deployed at global scale.
Responsibilities
- Own end-to-end system delivery, from architecture and data modeling through to production deployment, scaling, and long-term operation
- Define and evolve the core platform architecture, ensuring scalability, performance, and maintainability across a distributed AI system
- Refactor and reshape critical parts of the stack where needed to meet production-grade standards and scale requirements
- Set and enforce engineering standards, leading code reviews and driving technical excellence across the team
- Lead AI inference optimization and latency reduction efforts, ensuring high-performance, real-time user experiences across AI-driven services
Qualifications
- 7+ years of software engineering experience, with full lifecycle ownership (architecture, development, deployment, production operations)
- Strong proficiency in Python (Flask, FastAPI, or Litestar) and backend development
- Experience with cloud platforms (AWS, GCP, or Azure), Docker, and production system deployment
- Strong understanding of distributed systems, client-server architecture, and real-time protocols
(WebSockets and/or SSE), including complex integrations across Web, Unity, and AI modules
- Experience with databases and data modeling (PostgreSQL, MySQL, MongoDB, Redis, Memcached), including scalable schema design
- Exposure to frontend technologies (React, Svelte, or WebAssembly)
Job Type: Full-time
Experience:
- full stack engineering/AI modelling: 7 years (Required)
Work Location: In person
