Valarian Technologies is a dual-use technology company building critical tools to safeguard the future in an era of evolving global security challenges. We're rethinking security beyond traditional military domains, addressing asymmetric threats that impact our technological advantage, economic strength, and democratic institutions.

We build Acra – the platform foundation for everything we do as a dual-use technology company. The platform’s name, rooted in the Greek word for citadel (or, fortress), reflects the design and purpose of our infrastructure-agnostic secure enclaves: protecting critical data. Some of the government and commercial workflows include: increased operational resiliency for mission-critical systems and functions; enabling organizations to more quickly and widely adopt emerging technologies while ensuring the integrity of their intellectual property; information flow during disaster response scenarios, and zero-trust / least-privilege environments for M&A, attorney-client privileged communications, etc. And we’ve only scratched the surface.

At our core, we're driven by a shared mission and a belief in making a tangible impact on our world. Whether you join our London HQ or the wider global organisation, you’ll be a part of collaborative, high-performing teams, creating cutting-edge software, platforms, and infrastructure.

The Role

We are looking for a Senior Infrastructure Engineer to own and evolve the foundational infrastructure layer behind ACRA.

This is a deep infrastructure role. You will work across Kubernetes, Linux, networking, storage, service-to-service communication, observability, security boundaries, and production operations. You will be responsible for the systems that everything else depends on: clusters, networks, storage layers, ingress and egress paths, runtime infrastructure, deployment foundations, and operational reliability.

Infrastructure is part of the product at Valarian. ACRA only works if the underlying infrastructure is secure, observable, debuggable, resilient, and able to run across cloud, on-premise, bare-metal, sovereign, air-gapped, and customer-managed environments.

We are looking for someone with strong judgement and real production experience. This role values depth, operational correctness, and careful decision-making. You should be comfortable going deep into complex operational problems, understanding failure modes, debugging under pressure, and improving the reliability of the whole platform.

You should be comfortable operating close to the metal: debugging Kubernetes, understanding networking behaviour, reasoning about distributed storage, improving observability, and helping define the infrastructure patterns that ACRA will rely on as it scales.

This is not a generic DevOps support role, cloud administration role, or internal IT role. You will be a critical engineer in the team responsible for the infrastructure foundations of a high-trust platform.

What you’ll do:

Design, build, operate, and improve Kubernetes-based infrastructure for ACRA.

Own core infrastructure plumbing across networking, storage, workload scheduling, service communication, ingress, egress, DNS, certificates, and cluster-level security.

Operate and debug production Kubernetes environments across GCP, on-premise, bare-metal, sovereign cloud, air-gapped, and customer-managed deployments.

Work on multi-cluster Kubernetes environments, cluster networking, network policy, service mesh, and secure service-to-service communication.

Operate and evolve distributed storage systems, including storage classes, CSI drivers, capacity planning, replication, recovery, and failure handling.

Work with infrastructure technologies such as Kubernetes, Linux, Cilium, eBPF, Istio, Rook Ceph, Terraform, Argo CD, GitOps, Helm, and related CNCF tooling.

Build infrastructure automation that improves repeatability, reliability, and operational safety.

Improve observability across infrastructure layers, including metrics, logs, traces, alerting, dashboards, and operational runbooks.

Investigate and resolve complex production issues across networking, storage, Kubernetes, Linux, and application infrastructure.

Contribute to incident response, root-cause analysis, capacity planning, disaster recovery, and production readiness.

Define infrastructure standards, operational boundaries, security controls, and deployment patterns across the platform.

Work closely with engineering teams to make services easier to deploy, operate, monitor, and debug.

Contribute to the long-term technical direction of the DevOps department and the infrastructure foundations of ACRA.

What we are looking for:

Role

Senior Infrastructure Engineer

Similar Jobs

Senior Software Infrastructure Engineer

Graphcore

London•Posted: Jul 8•Deadline: Aug 16

ABOUT GRAPHCORE Graphcore is one of the world’s leading innovators in Artificial Intelligence compute.  It is developing hardware, software and systems infrastructure that will unlock the next generation of AI breakthroughs and power the widespread adoption of AI solutions across every industry.  As part of the SoftBank Group, Graphcore is a member of an elite family of companies responsible for some of the world’s most transformative technologies. Together, they share a bold vision: to enable Artificial Super Intelligence and ensure its benefits are accessible to everyone.   Graphcore’s teams are drawn from diverse backgrounds and bring a broad range of skills and perspectives. A melting pot of AI research specialists, silicon designers, software engineers and systems architects, Graphcore enjoys a culture of continuous learning and constant innovation.  JOB SUMMARY Join our dynamic Software Infrastructure team and take a pivotal role in scaling and managing our infrastructure. You will develop essential tools and services that empower our broader software team. Your contributions will enhance the build, test, deployment, and productisation processes of our Machine Learning Software components. Work with our High-Performance Computing (HPC) AI platforms and gain invaluable experience in distributed systems. THE TEAM The Software Infrastructure team provides critical platforms and services for software development teams across the business. Our responsibilities include managing the CI platform and services, build engineering, component integration, and packaging and release systems. We operate in squads, fostering a culture of service ownership and empowerment for our engineers. We focus on long-term engineering solutions and strive to eliminate toil wherever possible. RESPONSIBILITIES AND DUTIES * Develop, own, and maintain tools and services to support the software build and release process * Deploy and maintain services with Kubernetes and Docker * Manage our Cloud Infrastructure using tools such as Terraform * Support the technical development of junior and graduate engineer * Embody a strong engineering discipline for high reliability and minimal toil CANDIDATE PROFILE Essential: * Knowledge of Python/Go/C++ (or similar language) * Experience deploying services in the cloud (AWS preferred) * Deep understanding of Linux environments * Native user of CI/CD for production deployments * Experience with Infrastructure as Code (IaC) tools (e.g. Terraform/OpenTofu) Desirable * Experience using Kubernetes (k8s) or OpenStack * Experience with GitHub Actions * Experience with build tools (e.g. CMake) * Experience with modern observability tooling (e.g. Prometheus) * Experience with Grafana BENEFITS In addition to a competitive salary, Graphcore offers flexible working, a generous annual leave policy, private medical insurance and health cash plan, a dental plan, pension (matched up to 5%), life assurance and income protection. We have a generous parental leave policy and an employee assistance programme (which includes health, mental wellbeing, and bereavement support). We offer a range of healthy food and snacks at our central Bristol office and have our own barista bar! We welcome people of different backgrounds and experiences; we’re committed to building an inclusive work environment that makes Graphcore a great home for everyone. We offer an equal opportunity process and understand that there are visible and invisible differences in all of us. We can provide a flexible approach to interview and encourage you to chat to us if you require any reasonable adjustments. Applicants for this position must hold the right to work in the UK. Unfortunately at this time, we are unable to provide visa sponsorship or support for visa applications

Senior Security Assurance Engineer (Internal Penetration Testing)

Qube Research & Technologies

London•Posted: Jun 5•Deadline: Aug 16

Qube Research & Technologies (QRT) is a global quantitative and systematic investment manager, operating in all liquid asset classes across the world. We are a technology and data driven group implementing a scientific approach to investing. Combining data, research, technology, and trading expertise has shaped our collaborative mindset, which enables us to solve the most complex challenges. QRT’s culture of innovation continuously drives our ambition to deliver high quality returns for our investors. The Security Assurance team is responsible for identifying, assessing, and validating security risks across QRT’s technology environment. The team works closely with Security Engineers, Software Engineers, Infrastructure Engineers, Cloud Engineers, and Technology stakeholders to evaluate the effectiveness of security controls and strengthen the firm's overall security posture through adversarial testing and assurance activities. Your Future Role within QRT You will: * Conduct internal penetration testing across a wide range of systems, including trading infrastructure, cloud platforms, APIs, and business applications in both Windows and Linux environments. * Perform red team-style assessments and adversarial simulations to identify weaknesses in detection, response, and resilience capabilities. * Design and execute security assurance strategies to validate the effectiveness of security controls across applications, infrastructure, and cloud environments. * Coordinate external penetration testing engagements with third-party security vendors, including scoping, execution oversight, validation of findings, and remediation tracking across cloud, infrastructure, and application environments. * Identify, exploit, and clearly document vulnerabilities, providing actionable remediation guidance tailored to engineering teams. * Collaborate with product security and development teams to ensure vulnerabilities are properly remediated. * Support threat modelling exercises by providing an attacker’s perspective on system design and architecture. * Develop and maintain tooling, scripts, and frameworks to automate testing and improve coverage of security assessments. * Contribute to continuous security testing within CI/CD pipelines, including validation of SAST/DAST findings and runtime security controls. * Conduct security reviews of internal and third-party systems, validating real-world exploitability of identified risks. * Provide mentorship and training to engineers on common attack vectors, exploitation techniques, and secure design principles. * Stay current with emerging threats, vulnerabilities, and offensive security techniques relevant to financial systems and low-latency environments. Your present skillset: * 5+ years of experience in penetration testing, red teaming, or security assurance roles, with hands-on experience testing complex, large-scale systems. * Strong practical knowledge of offensive security techniques, including web application, API, network, and cloud exploitation. * Solid understanding of system internals, networking, and common vulnerability classes, including OWASP Top 10, logic flaws, authentication and authorisation issues, and race conditions. * Familiarity with both Windows and Linux environments from an attacker’s perspective. * Experience using standard penetration testing tools such as Burp Suite, Metasploit, Nmap, BloodHound, and similar offensive security tooling. * Ability to assess the real-world impact of vulnerabilities and prioritise risks in a high-stakes environment. * Ability to clearly document findings, explain exploitability, and provide practical remediation guidance to engineering and infrastructure teams. * Strong communication skills, with the ability to clearly articulate technical risks and remediation strategies to engineering stakeholders. * Ability to operate independently, manage multiple assessments, and provide senior-level technical judgement during security assurance activities. * Preferred: * Experience testing applications and services developed in languages such as Python, C++, Rust, Go, and Kotlin/Java. * Experience with cloud security testing across AWS or Azure, including IAM, network configuration, storage, managed services, and common cloud misconfigurations. * Experience developing custom penetration testing tools, automation, scripts, exploits, or fuzzers. * Experience integrating security testing into CI/CD pipelines or supporting continuous assurance practices. * Understanding of detection and response mechanisms, with the ability to evaluate or bypass them during controlled testing. * Experience conducting red team exercises, adversary simulations, or purple team engagements. * Experience with containerised environments, Kubernetes, infrastructure-as-code, or hybrid cloud infrastructure. * Knowledge of low-latency systems, financial trading environments, or high-performance distributed systems. * Relevant certifications such as OSCP, OSEP, OSCE, CRTO, CCT APP, CCT INF, or equivalent practical experience. QRT is an equal opportunity employer. We value diversity as essential to our success and are committed to creating an environment where employees can work openly, respectfully, and collaboratively. In addition to supporting professional achievement, QRT offers initiatives and programmes designed to help employees maintain a healthy work-life balance.

Infrastructure Team Lead

Speechmatics

London•Posted: Jul 1•Deadline: Aug 16

We're looking for an Infrastructure Team Lead to take ownership of the systems that power our AI research and development, ranging from bare metal GPU clusters through to the internal services our engineers rely on every day. This is a broad role with technical depth and people leadership. You will set the technical direction of the Infrastructure team, drive reliability and continuous improvements across the stack – from physical layer through to the software layer. Additionally, you will be investing in your engineers through 1:1s, coaching and creating career development opportunities. We’re a team that gets things done properly and multiplies the impact of others. If that sounds like an exciting problem, we’d love to talk. What you'll be doing * Leading, managing, and developing a team of Infrastructure Engineers, setting clear objectives and fostering a high-performance, collaborative culture * We are heavy users of infrastructure as code and automation, so you will be hands-on with PXE booting, Ansible for configuration, Terraform for VMware deployments and Helm for Kubernetes deployments * Conducting regular 1:1s, performance reviews, and development planning to build technical capability and support career progression * Owning operational stability across our infrastructure, including hardware monitoring, troubleshooting and disaster recovery testing * Acting as the escalation point for technical and operational issues, leading major incident response and driving resolution * Leading infrastructure strategy, including capacity and project planning * Driving standardisation, automation and optimisation to reduce toil * Leading vendor relationships with hardware vendors, managed service providers and other external contacts Who we are looking for * Proven experience in an Infrastructure Team Lead or Senior Engineer role, with strong people management and coaching skills * Experience leading or mentoring engineers, including setting objectives and supporting career development * A desire to go deep into any subject and a genuine love of learning on the job * Broad knowledge of the infrastructure supporting distributed systems — operating systems, observability tooling, networking, storage, containers and container orchestration * Comfortable troubleshooting Linux systems (we use Ubuntu) * Solid experience with infrastructure-as-code and automation tooling — we use Terraform and Ansible extensively * Experience with bare metal provisioning — we use PXE booting to automate hardware OS installs * Strong networking configuration and troubleshooting skills, including DNS/DHCP/IPAM * Excellent written and verbal communication skills, with the ability to influence at all levels and report up and out We encourage you to apply even if you do not feel you match all of the requirements exactly. The list of requirements is intended to show the kinds of experience and qualities we’re looking for, but it is not exhaustive. If you are interested in the role, the team, and our mission, we would love to consider your application. We are always open to conversations and look forward to hearing from you. Who we are: Speechmatics is the leading expert in Speech Intelligence, and uses AI and Machine Learning to unlock business value in human speech worldwide. We work with an amazing mix of global companies, and our technology can integrate into our customers stack irrespective of their industry or use case – making it the go-to solution to harness useful information from speech. Joining us means working with some of the smartest minds around the world, focused on cutting-edge projects and deploying the latest techniques to disrupt the market. We believe in putting people first; we’ll do all we can to help you develop your skills and give you the tools you need to thrive. Our Focus Fridays give you an undisturbed day of focus, offset with Together Tuesdays when we have our team meetings, so you've always got the right balance. We have structured a hybrid approach that includes 2-3 designated office days each week. This arrangement ensures that while we embrace the advantages of remote work, we also maintain the vital connection and synergy that only in-person interactions can foster. This is only the beginning; we’re looking for amazing people like you to continue our journey… What we can offer you: No matter what stage of your career you’re at - from paid internships and first-job opportunities through to management and senior positions - we’ll support you with the training and development needed to reach your career aspirations with us. There really is no shortage of opportunities here for you to get involved and collaborate with those around you to deliver your best work. We offer incredibly flexible working, regular company lunches, and birthday celebrations. But that’s not all. We’ve spoken to our teams to find out what they want. From Private Medical, and Dental for you and your family, through to global working opportunities, a generous holiday allowance and pension/401K matching, we want to make sure our employees and their families are looked after. Every employee will receive a working from home allowance for tech or home office equipment (on top of your choice of laptop and accessories of course). Our approach to parental leave is designed to support employees globally. While this varies by geo, we have support in place for parents (including adoption assistance and reproductive health services) to ensure they have the time and financial resources needed to care for their growing families. At Speechmatics, our mission is simple: Understand Every Voice out there. That's not just about our tech – it's the heart and soul of who we are. We welcome different experiences, viewpoints, and identities. For us, it’s not just the right thing to do; it’s our catalyst for sparking innovation and creativity. Our teams thrive in an environment that celebrates and supports everyone – no matter their gender, identity or expression, race, disability, age, sexual orientation, religion, belief, marital status, national origin, veteran status, pregnancy, or maternity status. But we don’t just open the door to diversity – we actively welcome it. Why? Because we believe every unique voice adds something special to our team, leading us to smarter solutions and a better workplace. So, come as you are and join our Speechling community. We’re building a place where every voice not only gets heard but is also respected and valued. For more information on us, please visit our website and follow Speechmatics on our social channels via Twitter, Facebook, LinkedIn, and YouTube. WE RELY ON LEGITIMATE INTEREST AS A LEGAL BASIS FOR PROCESSING PERSONAL INFORMATION UNDER THE GDPR FOR PURPOSES OF RECRUITMENT AND APPLICATIONS FOR EMPLOYMENT. #LI-HYBRID