Infrastructure Engineering - Traffic

In this role, you will be a key contributor to xAI’s Supercomputing team, focusing on building and optimizing scalable, high-performance traffic platforms that power our production inference engines. You will work on critical systems that manage traffic flow, service discovery, and network reliability across both on-premise and cloud-based Kubernetes clusters. Collaborating closely with Network Fabric Engineers and other technical teams, you will drive projects that enhance the stability and efficiency of our AI infrastructure, including support for large-scale training runs for advanced models like Grok 4 and beyond. This role demands deep technical expertise in Kubernetes, L4/L7 proxies like Envoy, and service discovery systems, along with a proactive approach to debugging and optimizing complex network performance issues from L3 to L7.

• Build and optimize traffic platforms that automate and simplify the lifecycle of production inference engines across dozens of on-premise and cloud clusters, managing core traffic primitives like load balancing, routing, overload control, authentication / authorization, encryption in transit.
• Manage, extend, and optimize xAI’s production inference capabilities with L4/L7 proxies such as Envoy, NGINX.
• Manage and extend xAI’s Service Discovery systems, both in and outside of kubernetes (DNS, xDS control planes).
• Collaborate with Network Fabric Engineers to improve host networking + fabric stability for large scale training runs (ie Grok 4 and beyond).
• Work with a fast, small technical team to execute projects in the critical path of xAI.

• 2+ years of experience operating Kubernetes clusters, or experience writing + deploying controllers.
• 2+ years of experience configuring and deploying Envoy, NGINX, HAProxy, or some other L7 software load balancer.
• 1+ years of experience deploying and configuring kubernetes CNI plugins (Calico, Cilium, Flannel) or experience with IPAM.
• 1+ years of experience with DNS systems (ex: CoreDNS, Unbound) or service discovery control planes (xDS)
• 1+ years of experience with cloud networking primitives (VPC Route Tables, Cloud NAT, Peering / Transit Gateways, CDN, Cloudflare Workers or equivalent)
• Experience with host level network proxies (iptables, nftables, IPVS, eBPF programs) is a plus.
• Deep experience with gRPC Client libraries (grpcio / grpc-go / grpc-java) is a plus.
• Experience with service mesh (Istio, Linkerd) is a plus.
• Demonstrated experience in working with Kubernetes and Envoy internals – can you tell us how k8s cached clients work? Can you tell us how Envoy scales and manages state?
• Demonstrated experience debugging performance and reliability issues that span from L3 to L7 (ex: how would a gRPC client in a cloud environment call a gRPC server in an on-prem server? Describe the entire network path and any issues to watch out for, including Service Discovery / DNS, gRPC channel management, egress proxies, VPC routing, peering/PNI, edge caching / CDN, L4 loadbalancing devices, host networking + virtualization, k8s networking, L7 routing, TLS / authnz, TCP/IP)

This role is based in the Bay Area (San Francisco and Palo Alto). Candidates are expected to be located near the Bay Area or open to relocation.

• Kubernetes

• Envoy / xDS

• Golang and Rust

1. Application Review: Submit your CV and a statement of exceptional work. Our team will review your application to assess fit.

2. Phone Interview (45 minutes): A brief conversation with a team member to discuss your background, key accomplishments, and motivation.

3. Main Interview Process 

• 2 Coding Assessments: Solve problems in a language of your choice.
  
• Systems Hands-On: Demonstrate practical skills in a live problem-solving session.
  
• Project Deep-Dive: Present your past exceptional work to a small audience.

$180,000 - $440,000 USD

Base salary is just one part of our total rewards package at xAI, which also includes equity, comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, and various other discounts and perks.