Principal Site Reliability Engineer, Infrastructure Architecture- AI Infrastructure Operations

About Nscale

Nscale is the GPU cloud engineered for AI. We provide cost-effective, high-performance infrastructure for AI start-ups and large enterprise customers.  Nscale enables AI-focused companies to achieve superior results by reducing the complexity of AI development. Our GPU cloud bolsters technical capabilities and directly supports strategic business outcomes, including cost management, rapid innovation, and environmental responsibility.

We thrive on a culture of relentless innovation, ownership, and accountability, where every team member takes pride in their work and drives it with excellence and urgency. As an Nscaler, you’ll build trust through openness and transparency, where everyone is inspired to do their best work. If you join our team, you’ll be contributing to building the technology that powers the future.

About The Role

Nscale’s AI Infrastructure Operations team keeps one of the most demanding AI platforms in the industry running.  At our scale, the design decisions we make this year set the failure modes we live with for the next five.

We’re looking for a Principal Site Reliability Engineer, Infrastructure Architecture to be the architectural authority for how our platform is designed, connected, and recovered.

This is a design-first role.  You will own the reference architecture for Nscale’s GPU, network, and control-plane platforms; decide where failure domains and trust boundaries sit; and make sure every major system we build has a known blast radius, a tested recovery path, and a clear owner.  You'll work alongside the teams doing bring-ups, upgrades, and migrations, and you'll join major incidents when the cause turns out to be in the design.  You'll be a peer to our existing architecture lead, not a backup; the two of you share ownership of both the design and the operating model, so neither one is a single point of failure.

What You'll Be Doing

• Owning the end-to-end reference architecture for Nscale’s AI and HPC infrastructure: compute, network fabric, storage, control plane, and the core services underneath them
• Designing multi-site and multi-region topologies, including failure domains, tenant isolation, and secure service enclaves for sovereign and hyperscale customers
• Separating control plane from data plane by design, so that a management-layer outage never takes customer workloads down with it
• Defining the target-state architecture and the multi-year roadmap to reach it, including what we retire, consolidate, or rebuild
• Leading architecture reviews across Engineering, Network Operations, and Fleet Operations; writing and approving the RFCs and architecture decision records (ADRs) that other teams build against
• Setting the architectural standards every new system must meet before it ships: SLOs, observability, capacity models, dependency maps, and documented failure modes
• Running pre-mortems and red-team reviews on major designs to find single points of failure and hidden coupling before production does
• Joining major incidents when the root cause is architectural, and follow the fix through to the design
• Co-owning the operating model with the SRE team: operational readiness reviews (ORR), incident severity and post-incident review (PIR) standards, and production access and break-glass policy
• Making sure the teams running each system can deploy, upgrade, and recover it without needing you in the room
• Planning and reviewing site bring-ups, fleet upgrades, and migrations of live customer workloads
• Running DR tests and game days so we know recovery works
• Using incident and on-call data to decide what to redesign next
• Mentoring senior engineers in systems design, so that architectural knowledge and decision-making never sit with a single person

About You

• 10+ years building and running large-scale production infrastructure, including on-call for systems you designed, and several years as a staff, principal, or architect-level engineer
• A track record of architectures you designed that are running in production today; you can walk us through the tradeoffs, what broke, and what you would change
• You've led major incidents and run large migrations or site bring-ups
• Working knowledge of change management, staged rollouts, SLO-based alerting, and post-incident reviews
• Deep expertise in distributed systems design: consistency models, consensus and replication, partition handling, and graceful degradation
• Strong networking fundamentals at the design level, including L3 fabrics, BGP, EVPN/VXLAN, segmentation, and multi-site connectivity
• Experience designing secure multi-tenant platforms: identity, PKI and secrets management, network isolation, and zero-trust boundaries
• Clear technical writing; your design docs, RFCs, and ADRs hold up under scrutiny, and engineers can build directly from them
• Proven ability to drive architectural decisions across teams without direct authority, including saying no to designs that will not hold up
• Strong software engineering skills; you can prototype a design, review production code, and spot when an implementation has drifted from the intended architecture
• Sound judgement when reliability, velocity, and cost pull in different directions, and the ability to explain the tradeoff to engineers and executives alike

Nice to Have

• Architecting AI or HPC platforms at scale, including GPU clusters, InfiniBand or RoCE fabrics, and workload schedulers such as Slurm or Kubernetes-based GPU scheduling
• Designing sovereign, regulated, or air-gapped cloud environments
• Bare-metal and hybrid cloud architecture, including provisioning pipelines, a CMDB/DCIM as the source of truth, and hardware lifecycle automation
• Observability architecture for high-cardinality, high-throughput environments
• Kubernetes platform architecture across many clusters and sites
• Structured design analysis methods such as failure mode and effects analysis (FMEA), threat modelling, or C4 diagrams
• A history of step-change reliability or scalability gains that came from a redesign rather than a patch

On-Call and Pace

When an incident turns out to be a design problem, you'll be pulled in and you'll own the fix.

What We Can Offer You

At Nscale, you'll find a collaborative, supportive, and innovative environment where your contributions spark real impact. We're building something extraordinary, and we want you at the core.

• Highly competitive package (base + equity) with reviews every 12 months. 🚀
• Join the fastest-growing tech startup, your chance to push boundaries, collaborate with brilliant minds, and make your mark on cutting-edge AI. ✨
• Expect a dynamic progression plan tailored to your ambitions. Grow by trying new things, leading, challenging the status quo, and owning your impact, always with our full support. 
• Human-First Flexibility: We treat you as humans first. 🫶🏽 Our flexible workplace trusts Nscalers to deliver, giving you the autonomy to shape your day around life's moments.

Join our thriving remote-first team. Geography is no barrier to impact or connection. We build seamless virtual collaboration, empowering you, wherever you work.

Equal Opportunities Statement

We strongly encourage applications from people of colour, the LGBTQ+ community, people with disabilities, neurodivergent people, parents, carers, and people from lower socio-economic backgrounds.

If there’s anything we can do to accommodate your specific situation, please let us know.

The responsibilities outlined in this job description are not exhaustive and are intended to provide a general overview of the position. The employee may be required to perform additional duties, tasks, and responsibilities as assigned by management, consistent with the skills and qualifications required for the role.