---
title: 'Software Engineer – Senior Backend at FriendliAI'
canonical: 'https://feeny.ai/job/software-engineer-senior-backend-friendliai-seoul-1ne481sqd82c'
type: 'job'
last_seen: '2026-09-05'
---

# Software Engineer – Senior Backend at FriendliAI

- **Company:** FriendliAI
- **Location:** Seoul, South Korea
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-03-15
- **Last confirmed live:** 2026-09-05
- **Apply:** https://jobs.ashbyhq.com/friendliai/5fd918c3-70c8-44f1-b080-2aef9520b312

## Job description

## ABOUT THE JOB

We believe using large language and multimodal models should be as simple as calling an API. To achieve this in production, we need to serve enterprises across clouds, with authentication, billing, multi-tenant isolation, and zero tolerance for downtime.

We are looking for a Senior Backend Engineer who is excited by the full breadth of what it takes to run a platform in production. You will own the business logic layer that sits between our inference engine and every customer who relies on it. Your work spans API engineering, service development, and data architecture. If you like solving problems that only reveal themselves in the wild, this is your role: edge cases in multi-cloud orchestration, enterprise requirements that don’t fit neatly into a spec, performance bottlenecks that are hard to reproduce.

You will move across domains, make decisions under uncertainty, and build systems that work cleanly, reliably, and at scale. We are looking for people with a track record of owning complex systems in production and solving unique problems. A great candidate is a strong collaborator who enjoys solving complex architectural challenges, cares deeply about developer workflows, and is eager to help define the future of AI adoption.

## KEY RESPONSIBILITIES

- Own the architecture and evolution of core backend microservices powering our AI inference platform, from the API layer through business logic to the data layer.
- Design and build production-grade APIs (REST, gRPC, GraphQL) that serve as the foundation for AI deployments, developer integrations, and enterprise workflows.
- Build and scale enterprise-grade platform capabilities: authentication, RBAC, billing, organization management, and secure multi-tenant SaaS infrastructure.
- Develop AI-specific platform features, including LLM deployment workflows and inference-specific service integrations.
- Design and optimize data models and pipelines across OLTP (PostgreSQL) and OLAP (ClickHouse) systems.
- Collaborate with infrastructure engineers on multi-cloud deployment and resource orchestration pipelines.
- Set reliability and performance standards for the services you own, resolving production issues with urgency and rigor
- Drive engineering quality through design reviews, automated testing, and CI/CD.

## QUALIFICATIONS

- 5+ years of backend or systems engineering experience in production environments
- Bachelor's or Master's degree in Computer Science, Computer Engineering, or equivalent.
- Expertise in Python and modern frameworks (e.g., FastAPI); should be able to write code others learn from.
- Strong experience designing and operating distributed systems at scale.
- Solid API design experience across REST, gRPC, and GraphQL.
- Proficiency in data modeling and SQL, with hands-on experience in PostgreSQL and OLAP systems such as ClickHouse.
- Working knowledge of LLM serving.
- Experience building secure, multi-tenant SaaS architectures: authentication, RBAC, and compliance requirements.
- Familiarity with cloud-native development and observability tooling (OpenTelemetry or equivalent).
- Strong systems thinking and ability to reason about failure modes.

## PREFERRED EXPERIENCE

- Hands-on experience with AI or model serving infrastructure.
- Experience with Kubernetes for production container orchestration and scaling.
- Background building developer-facing SDKs, CLIs, or internal engineering platforms.
- Exposure to multi-cloud environments and cross-cloud resource management.
- Experience leading incident response and postmortems for production systems.
- Basic familiarity with modern frontend frameworks (e.g., React/Next.js http://next.js) for cross-functional collaboration.

## BENEFITS

- Flexible working hours
- Daily lunch and dinner provided; unlimited snacks and beverages
- Supportive and highly collaborative work environment
- Health check-up support and top-tier equipment/hardware support
- A front-row seat to the generative AI infrastructure revolution
- Competitive compensation, startup equity, health insurance, and other benefits.

## ABOUT FRIENDLIAI

FriendliAI is building the world’s best AI inference platform that makes large language and multi-modal models fast, efficient, and deployable at scale. We power high-throughput, low-latency AI workloads for organizations worldwide and integrate directly with Hugging Face, giving developers instant access to over 600,000 open-source models.

We are a small, fast-moving team doing work that matters at one of the most exciting moments in the history of technology. With our world-class inference engine, we are building a platform that the AI industry can actually rely on.

## About FriendliAI

## Company Overview
- **One-liner**: FriendliAI is The Frontier AI Inference Cloud, providing a highly optimized platform for deploying, scaling, and monitoring large language and multimodal models with unmatched speed and cost efficiency.
- **Entity Type**: Private (Seed stage; $26.7M total funding)
- **Headquarters**: San Francisco, California, United States (with offices in Seoul, South Korea and Redwood City, CA)
- **Founded**: 2021
- **Founders**: Byung-Gon Chun (CEO) and Gyeong-In Yu (CTO) – the researchers who invented the continuous batching technique now standard in AI inference.

## Core Business
- **Primary industry**: AI Infrastructure / Cloud Inference Platform (Infrastructure as a Service)
- **Target customers**: B2B – enterprises and AI teams deploying generative AI and agent workloads at production scale; focuses on open-weight and custom models.
- **Mission**: Democratize access to production-grade AI so teams can focus on building great products.

## Products & Services
- **[FriendliAI Inference Cloud](https://friendli.ai/)**: A fully managed platform that instantly deploys 580,000+ Hugging Face models (language, audio, vision) with one click. Supports bring-your-own fine-tuned or proprietary models. Key features:
  - Custom GPU kernels, smart caching, continuous batching, speculative decoding, and parallel inference.
  - 2×+ faster inference than standard solutions, up to 3× faster than vLLM.
  - 50% to 90% cost savings relative to closed model APIs.
  - 99.99% uptime SLAs, geo-distributed infrastructure, enterprise-grade fault tolerance.
  - SOC 2 Type II and HIPAA compliant (March 2026).

## Market Standing
- **Valuation/Market Cap**: Not disclosed (private company)
- **Key Metric**: Total funding $26.7M (two seed rounds: $6.7M in 2021 and $20M led by Capstone Partners in September 2025)
- **Notable Investors/Partners**: Capstone Partners (lead investor in latest round), plus two other investors in the first seed round.
- **Growth Signals**:
  - Headcount grew 90% YoY to ~45 employees (as of mid-2026).
  - Active job postings: 19 positions (up 1800% YoY) – strong hiring momentum.
  - Appointed Brian Yoo (former Moloco COO) as Chief Business Officer in April 2026 to drive hypergrowth.
  - Achieved SOC 2 Type II and HIPAA compliance in March 2026, opening regulated markets.
  - LinkedIn followers grew 257% yearly (8,221 followers).

## Competitive Advantages
- **Inventor of continuous batching** – the technique is now industry standard, giving FriendliAI deep technical expertise.
- **Purpose-built inference engine** that constantly evolves for state-of-the-art models, delivering 2–3× speed improvements over alternatives like vLLM.
- **Massive model library** – 580,000+ Hugging Face models deployable instantly with zero manual optimization.
- **Enterprise-grade reliability** – 99.99% SLA, SOC 2 Type II, HIPAA, multi-cloud scaling.
- **Cost leadership** – 50–90% savings vs. closed model APIs, maximizing tokens per dollar.

## Strategic Focus
- **Hypergrowth** – scaling sales, engineering, and solutions architecture teams globally (US and Korea).
- **Compliance and enterprise readiness** – recent SOC 2/HIPAA certification to serve healthcare and regulated industries.
- **Multi-cloud and geo-distribution** – expanding infrastructure footprint for global low-latency inference.
- **Open-weight and custom model support** – enabling model ownership and flexibility for enterprises.

## Why Work Here
- **Culture**: “Boldest innovations come from great teams” – passionate, humble, curious builders. Mission-driven to democratize AI.
- **Work policy**: Hybrid (San Francisco and Seoul offices); some roles are in-office (Seoul) or hybrid (SF). Employees engage in a mix of remote and on-site work.
- **Engineering focus**: Heavy emphasis on AI inference engine, GPU kernels, Python developer tools, AI agents, backend, and platform security. High technical bar.
- **Perks**: Not explicitly listed, but fast-growing startup with significant impact in the AI infrastructure space; opportunity to work on cutting-edge inference optimization.
- **Locations**: San Francisco (HQ), Redwood City, CA, and Gangnam-gu, Seoul – global team with cross-cultural collaboration.

## Sources
1. [friendli.ai](https://friendli.ai/)
2. [friendli.ai/careers](https://friendli.ai/careers)
3. [jobs.ashbyhq.com/friendliai](https://jobs.ashbyhq.com/friendliai)
4. [builtin.com/company/friendliai](https://builtin.com/company/friendliai)
5. [linkedin.com/company/friendliai](https://www.linkedin.com/company/friendliai)

## Other roles at FriendliAI

- [Director of Product Management](https://feeny.ai/job/director-of-product-management-friendliai-san-francisco-vckbhh439mws) — San Francisco, CA
- [Software Engineer - Full Stack](https://feeny.ai/job/software-engineer-full-stack-friendliai-seoul-2kvnfm2hejx8) — Seoul, South Korea
- [Software Engineer – Cloud Infrastructure](https://feeny.ai/job/software-engineer-cloud-infrastructure-friendliai-san-francisco-z8fjtpn12kpn) — San Francisco, CA
- [Software Engineer - Cloud Infrastructure](https://feeny.ai/job/software-engineer-cloud-infrastructure-friendliai-seoul-rf473fpa9850) — Seoul, South Korea
- [Account Executive](https://feeny.ai/job/account-executive-friendliai-san-francisco-z6e1g3bcymfg) — San Francisco, CA
- [Software Engineer – Python Developer Tools](https://feeny.ai/job/software-engineer-python-developer-tools-friendliai-seoul-z74wd9kp8fex) — Seoul, South Korea
- [Software Engineer – GPU Kernel](https://feeny.ai/job/software-engineer-gpu-kernel-friendliai-seoul-yg1eq3ks7m5a) — Seoul, South Korea
- [Software Engineer – AI Inference Engine](https://feeny.ai/job/software-engineer-ai-inference-engine-friendliai-seoul-8pdpe18z4ejk) — Seoul, South Korea
- [Customer Success Engineer (contract based)](https://feeny.ai/job/customer-success-engineer-contract-based-friendliai-seoul-9ang4dybr9c9) — Seoul, South Korea
- [Software Engineer - Senior Backend](https://feeny.ai/job/software-engineer-senior-backend-friendliai-san-francisco-h5x2ghcnfrg7) — San Francisco, CA