Cluster Site Reliability Engineer

Own the physical reality of the platform in one of our seven regions. You bring up new GPU racks, validate InfiniBand fabric end-to-end, and keep the cluster running at the SLA. This is a hands-on role;
you will see the hardware.
Type Full-time · IC4-IC6
Stack Linux InfiniBand (NDR / XDR) NCCL / RCCL Kubernetes (host-level) Terraform Prometheus / Grafana Go or Python
Hiring manager replies within 5 business days.
The team
About the teamCluster SRE is six engineers across the seven regions. Each region has a primary and a secondary;
you will be one of those for your region. The team coordinates daily, deploys weekly, and rotates a global pager.
Reports to the head of cluster engineering. Primary on a single region;
rotates secondary for one neighboring region.
What you'll do
01 Bring up new B200 / B300 / MI300X racks: cabling, ToR config, NCCL/RCCL all-reduce validation, MFU baseline tests.
02 Drive InfiniBand fabric to spec - NDR / XDR depending on the rack - and chase residual bit-error budget down to zero.
03 Run capacity planning across seven regions: forecast demand, model power and thermal headroom, work with procurement on lead times.
04 Own the regional incident response. P1 incidents page within fifteen minutes;
resolution target is four hours.
05 Build and maintain the bring-up runbook so the second hire after you can do their first rack solo.
06 Carry the global pager about one week per six, alongside runtime and customer engineering.
The bar
What we're looking forFive-plus years operating large compute clusters — supercomputing centers, hyperscaler infra, or HPC at a national lab count.
Deep InfiniBand and Ethernet RoCE experience: subnet manager tuning, fabric debugging, lossless networking.
Comfort writing Go or Python for tooling. We are not strict about which.
Calm under load. You will be the named person on a $50M-ARR account when something goes wrong.
Nice to have, not requiredExperience with NVIDIA Bright / Base Command Manager.
Bare-metal provisioning systems: Tinkerbell, MAAS, Razor, or in-house equivalents.
CompensationIn writing, like everything elseWe publish bands. We meet them. The number you see on the offer is the same number your future peers got at the same level. We do not negotiate;
we level.
Base$210,000 – $340,000 USD (US Cologix regions) / equivalent in CA.
EquityMeaningful early-stage equity, refreshed on tenure milestones.
NotesOn-site pay differential at Cologix regions outside SF / NYC / Bay Area is +5-10% to compensate for travel.
Equal opportunityWe hire on the work. Race, gender, age, nationality, religion, sexual orientation, disability, and veteran status do not factor into our decisions. We sponsor visas for senior roles in the US, UK, and EU — bring it up on the manager call.
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