About Fluidstack

Fluidstack is building GPU supercomputers for top AI labs, governments, and enterprises. Our customers include Mistral, Poolside, Black Forest Labs, Meta, and more.

Our team is small, highly motivated, and focused on providing a world class supercomputing experience. We put out customers first in everything we do, working hard to not just win the sale, but to win repeated business and customer referrals.

We hold ourselves and each other to high standards. We expect you to care deeply about the work you do, the products you build, and the experience our customers have in every interaction with us.

You must work hard, take ownership from inception to delivery, and approach every problem with an open mind and a positive attitude. We value effectiveness, competence, and a growth mindset.

About the Role

Our Network Reliability Engineers are the backbone of Fluidstack's platform. You'll utilize deep networking expertise and software engineering to keep our high-performance network fabrics fast, reliable and cost-efficient at scale. Our NREs operate RDMA fabrics, the datacenter network, and our WAN backbones.

Focus

• Super-charge the network stack. Tune TCP/IP, RDMA (primarily RoCE congestion control), kernel-bypass frameworks (DPDK, XDP, eBPF) and NIC offloads to squeeze microseconds off packet latency for AI & HPC workloads.

• Deploy & optimize at scale. Roll out new ToR/spine switches (from NVIDIA, Arista, Juniper, and others), validate SmartNIC and BlueField networking, configure BGP/EVPN fabrics, and optimize flow control (PFC, ECN) for zero-loss transport.

• Automate observability. Build NIC-to-orchestrator telemetry pipelines, packet-loss detection bots, and real-time throughput/latency dashboards.

• Root-cause the gnarly stuff. Lead packet captures, congestion analyses and latency regressions; turn insights into switch firmware patches, kernel tuning and topology optimizations.

• Drive vendor collaboration. Pair with networking vendors to debug hardware, accelerate RDMA paths, validate optics, and integrate emerging network hardware (800G/1.6T, LPO/CPO)

• Continuously improve. Inject link failures, run game-days simulating network partitions and codify post-mortem learnings into SLIs/SLOs that matter to customers.

About you

• 7+ yrs in network-heavy SRE, performance engineering or data-center networking.

• Mastery of Linux networking stack and protocol-level debugging (TCP, IB, RoCE).

• Production experience with many vendors (Mellanox/NVIDIA, Arista, Juniper, etc.), multi-layer fabrics, and network overlays (VXLAN, Geneve).

• Fluency in Python, Go or Rust; solid Infra-as-Code & CI/CD chops.

• Familiarity with DPDK, XDP, eBPF and InfiniBand/RoCE.

• Proven track record scaling low-latency, high-throughput networks for AI/ML or HPC clusters.

Benefits

• Competitive total compensation package (cash + equity).

• Retirement or pension plan, in line with local norms.

• Health, dental, and vision insurance.

• Generous PTO policy, in line with local norms.