Principal Site Reliability Engineer - AI Infrastructure Operations

About Ironwood Digital Ironwood Digital is the GPU cloud engineered for AI. We provide cost-effective, high-performance infrastructure for AI start-ups and large enterprise customers. Ironwood Digital 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 Ironwood Digital r, 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 At Ironwood Digital , our AI Infrastructure Operations team is responsible for the reliability and scalability of one of the most demanding AI platforms in the industry. We value engineers who think in systems, lead through influence, and raise the bar for operational excellence across the organisation. We’re looking for a Principal Site Reliability Engineer (SRE) to provide technical leadership across our AI Infrastructure Operations domain. This is a senior, highly impactful role focused on setting reliability strategy, designing foundational systems, and driving cross-team improvements at scale. You will operate as a technical authority for reliability, automation, and operational architecture across Ironwood Digital ’s GPU, network, and control-plane platforms. What You'll Be Doing Owning and evolving the long-term reliability strategy for Ironwood Digital ’s AI and HPC infrastructure Designing and leading the development of large-scale control-plane systems, automation frameworks, and operational tooling Defining reliability standards, SLO frameworks, and operational best practices used across multiple teams Acting as a senior technical escalation point during critical incidents, guiding resolution and ensuring systemic fixes Identifying structural reliability risks and driving cross-functional initiatives to address them at the architectural level Partnering with Engineering, Network Operations, and Fleet Operations leadership to influence platform design and operational maturity Mentoring senior and mid-level engineers, raising the overall quality and effectiveness of SRE practices Driving measurable improvements in availability, MTTR, cost efficiency, and operational scalability About You 10+ years of experience in Site Reliability Engineering, Systems Engineering, or Software Engineering roles operating complex, large-scale infrastructure Expert-level software engineering skills, with a strong track record of building production-grade automation and systems Deep expertise in Linux, networking, and distributed systems design at scale Extensive experience debugging and resolving failures across hardware, OS, networking, and application layers Proven ability to lead technical initiatives across teams without direct authority Strong systems-thinking mindset, with the ability to balance reliability, velocity, and cost Nice to Have Deep hands-on experience with AI or HPC platforms, including GPUs, high-speed interconnects (InfiniBand/RDMA), and workload schedulers (e.g. SLURM) Experience designing observability systems for high-cardinality, high-throughput environments Familiarity with Kubernetes at scale and hybrid or bare-metal cloud architectures A history of driving step-change improvements in reliability, scalability, or operational efficiency What We Can Offer You At Ironwood Digital , 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 Ironwood Digital rs 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 provi