Senior Software Engineer - XenServer Toolstack

This Software Engineering position focuses on developing the control plane for XenServer, a commercial virtualization platform built on the open-source Xen hypervisor. The control plane is a critical component that manages virtual machines, storage, and networking across clusters of physical hosts and exposes the public XenServer API. It sits at the heart of the platform providing a unique opportunity to shape and influence how modern infrastructure is managed at scale.

You will work primarily in OCaml, a functional programming language well-suited to building safe and maintainable systems software. The role involves deep technical challenges such as distributed system orchestration, performance optimization, and robust API design, all within an active open-source and enterprise environment. This is a role for engineers who want to grow their skills while solving problems that matter in the real world.

XenServer powers critical infrastructure worldwide from hospitals and government systems to cloud-scale platforms and high-security environments. It supports thousands of virtual desktops, powers ultra-low-latency network appliances, and runs workloads where performance and reliability are non-negotiable. By contributing to XenServer, you will be helping organizations around the world operate with confidence.

What you will do:

• Design, implement, test, and maintain the software powering XenServer's control plane.
• Lead the development of cross-team features collaborating across disciplines and domains.
• Participate in the evolution of the XenServer architecture helping to modernize and scale the platform.
• Contribute to open-source projects including Xen, the Linux kernel, and XAPI.
• Work closely with product managers, support engineers, and customers to align engineering with real-world needs.
• Operate in a self-organizing agile team that values quality feedback and continuous improvement.

What we are looking for:

• Software development experience on Unix/Linux systems.
• Familiarity with procedural languages (e.g. C, C++, C#, Java) and scripting languages (e.g. Python).
• Interest or experience in functional programming (e.g. OCaml, Haskell, F#, Scala, ML).
• Understanding of software engineering best practices including automated testing, code review, and CI/CD.
• A thoughtful approach to building scalable, maintainable, and correct systems.

Preferred qualifications:

• Bachelor's degree or higher in Computer Science or equivalent experience.
• Experience with virtualization, particularly Xen or XenServer.
• Familiarity with large-scale or cloud-native infrastructure.
• Background in agile methodologies like Scrum.

Why this role matters:

This is a high-impact engineering role at the core of a widely deployed and mission-critical virtualization platform. The control plane is central to how organizations manage infrastructure, and your contributions will directly shape the experience of customers running healthcare, finance, education, and cloud environments across the globe. This role offers the chance to work on technically rich challenges from performance tuning and cluster coordination to open API design while building deep expertise in systems engineering and functional programming.

Whether your goal is to lead major features, grow into architectural leadership, or contribute meaningfully to open source, this position gives you the platform to make a lasting impact.

About Us:

Cloud Software Group is one of the world's largest cloud solution providers serving more than 100 million users around the globe. When you join Cloud Software Group, you are making a difference for real people, each of whom count on our suite of cloud-based products to get work done from anywhere. Members of our team will tell you that we value passion for technology and the courage to take risks. Everyone is empowered to learn, dream, and build the future of work.

We are on the brink of another Cambrian leap -- a moment of immense evolution and growth. And we need your expertise and experience to do it. Now is the perfect time to move your skills to the cloud.

Cloud Software Group is firmly committed to Equal Employment Opportunity (EEO) and to compliance with all federal, state, and local laws that prohibit employment discrimination. All qualified applicants will receive consideration for employment without regard to age, race, colour, creed, sex or gender, sexual orientation, gender identity, gender expression, ethnicity, national origin, ancestry, citizenship, religion, genetic carrier status, disability, pregnancy, childbirth or related medical conditions (including lactation status), marital status, military service, protected veteran status, political activity or affiliation, taking or requesting statutorily protected leave, and other protected classifications.

If you need a reasonable accommodation due to a disability during any part of the application process, please email us for assistance.