Senior Software Engineer, Infrastructure - Python & Kubernetes
PhysicsX is growing rapidly, and so is the infrastructure that underpins its platform. The company is building core infrastructure that is reliable, secure, scalable and reproducible across multiple cloud providers and on-premises environments. As the platform evolves to serve increasingly complex engineering workloads, the foundational infrastructure layer becomes ever more critical.
PhysicsX is looking for a Senior Software Engineer to join its Platform SRE Core Infrastructure team. This role is responsible for the design, provisioning and operation of the shared infrastructure on which the entire PhysicsX platform depends. You will work across infrastructure as code, Kubernetes cluster management, secrets management, GPU drivers, networking and multi-tenancy architecture to ensure the platform is dependable, scalable and secure. This is a role for an engineer who combines deep infrastructure expertise with a reliability engineering mindset and an appreciation for the developer experience of the teams that consume the platform.
What you will do: - Own the design and delivery of core infrastructure across AWS, GCP, Azure and on-premises environments using Terraform and Crossplane. - Architect and operate Kubernetes clusters supporting both single-tenant and multi-tenant workloads, with a strong emphasis on isolation, performance and reliability. - Define and implement infrastructure provisioning patterns using Crossplane compositions and Terraform modules, ensuring reproducibility and auditability across environments. - Design and operate secrets-management solutions, including dynamic secret provisioning, rotation and fine-grained access control integrated with cluster identity. - Manage and maintain GPU driver configurations and accelerated compute node pools, ensuring compatibility and performance for AI and simulation workloads. - Own cluster networking design, including CNI selection, Istio service-mesh integration, ingress strategy and cross-cluster connectivity. - Implement and maintain vCluster-based multi-tenancy to provide strong workload isolation within shared infrastructure. - Develop lightweight Kubernetes operators or controllers where automation of infrastructure lifecycle tasks requires it. - Establish SLOs and reliability targets for core infrastructure components and lead the response to production incidents. - Partner with security and platform teams to enforce infrastructure governance, network policies and compliance controls. - Contribute to and uphold engineering standards across the platform organisation.
What you bring: - Five or more years of professional experience operating Kubernetes in production, with a thorough understanding of cluster architecture, the scheduler, networking, storage and the API lifecycle. Kubernetes certifications such as CKAD, CKA or CKS are highly desirable. - Significant hands-on experience designing and operating Crossplane compositions, providers and managed resources in production environments. - Strong experience authoring, structuring and operating Terraform at scale, including state management, module design and CI integration. - Practical experience operating infrastructure across more than one cloud provider and on-premises environments, with an understanding of differences in identity, networking and storage. - Experience designing and implementing both single-tenant and multi-tenant Kubernetes architectures, with strong views on isolation, resource governance and operational overhead. - Experience with tools such as Vault, External Secrets Operator or cloud-native secret stores, including dynamic provisioning and rotation. - Solid knowledge of Kubernetes networking, CNI plugins, Istio service mesh and ingress patterns. Experience with cross-cluster or hybrid connectivity is valuable. - Experience using vCluster or similar tooling to provide lightweight, isolated Kubernetes environments within shared clusters. - Familiarity with GPU driver management, device plugins and the operational considerations of running accelerated workloads in Kubernetes. - At least lightweight experience writing or extending Kubernetes operators or controllers, ideally in Golang or Python. - Comfort writing code to automate and extend infrastructure. Python and Golang are the primary languages used across the platform; exposure to functional programming languages such as Erlang, Elixir or OCaml is appreciated. - A platform-engineering mindset, thinking about infrastructure as a product consumed by engineering teams and prioritising usability, documentation and long-term maintainability. - A solid grounding in distributed-systems concepts, including failure modes, consistency and the operational challenges of running systems at scale.
Ideally, you will also have experience with GitOps workflows using tools such as Argo CD or Flux, and contributions to open-source infrastructure or Kubernetes ecosystem projects.
PhysicsX is headquartered in the United Kingdom, with offices in London, New York and Singapore and an expanding presence in the Bay Area. The company offers the opportunity to help shape an AI-native engineering company at a formative stage, working on real-world industrial and societal challenges alongside a collaborative team of engineers, scientists and operators. It operates with a flat structure in which good ideas win wherever they come from, and supports a sustainable pace through a hybrid model combining time in the Shoreditch office with work-from-home days.
Benefits include equity options, a 10% employer pension contribution, free office lunches, enhanced parental leave, the YellowNest nursery scheme, 25 days of annual leave plus public holidays, private medical insurance, a Wellhub subscription, eye tests, personal-development support, an Employee Assistance Programme, the Bike2Work scheme, a season-ticket loan and Octopus EV salary sacrifice.