Backend Engineer - API · xAI

Sat, 25 Apr 2026 13:03:54 GMT
Engineering

xAI · London, UK · onsite

About the Role

As a Backend Engineer - API at xAI, you will play a key role in building the xAI API that serves our models to developers worldwide. You will own the end-to-end system responsible for high-throughput inference, handling billions of tokens per minute with low latency and high availability.

Responsibilities

Build the xAI API that serves our models to developers worldwide

Own the end-to-end system responsible for high-throughput inference, handling billions of tokens per minute with low latency and high availability, including model serving infrastructure, request routing, SDK development, rate limiting, observability, and efficient scaling

Basic Qualifications

Expert knowledge of either Rust or C++

Experience in designing, implementing, and maintaining reliable and horizontally scalable distributed systems

Knowledge of service observability and reliability best practices

Experience in operating commonly used databases such as PostgreSQL, Clickhouse, and MongoDB

Preferred Skills and Experience

Experience with LLM inference engines and serving frameworks (e.g., SGLang, TensorRT, vLLM)

Experience designing or building with agent SDKs and agent orchestration frameworks

Experience with Docker, Kubernetes, and containerized applications

Expert knowledge of gRPC (unary, response streaming, bi-directional streaming, REST mapping)

Benefits

Competitive salary

Opportunity to work with a highly motivated and focused team

Flat organisational structure

Strong prioritisation skills

Excellent communication skills

How to Apply

If you are a motivated and experienced Backend Engineer looking for a new challenge, please submit your application.