Platform Engineer (Defence & Security)

Reaktor’s tech community is looking for a Senior Platform Engineer to join our Defence & Security Business Unit in Helsinki.

Our Defence & Security Unit brings together around 70 professionals working on technically demanding and societally meaningful projects. Here, you can take ownership of important technical decisions and build systems whose reliability and security genuinely matter.

We are looking for someone who enjoys designing and building large-scale on-premise and private cloud platforms. If you love working hands-on with IaC, CI/CD, security, and observability to solve complex infrastructure challenges alongside product teams and clients, you might be a great fit

Your role is to turn complex, security-critical infrastructure into a reliable platform that development teams can build on.

You will design, build and operate on-premise infrastructure and private cloud platforms that support critical products and our clients’ business needs.

You will be part of both a consulting team working closely with the client and a productisation team bringing solutions to international markets. The role combines hands-on engineering, collaboration and technical decision-making.

You enjoy turning complex, fragmented infrastructure into streamlined, scalable platforms that let teams move quickly and reliably.

• Hands-on experience in platform/ infra/ DevOps roles. We don’t have a hard limit with years of experience, but we’ve noticed that these competencies often take 8+ years to accumulate.
• Deep expertise in on-premise infrastructure, including production experience with virtualization technologies (e.g., VMware vSphere, KVM, OpenStack), networking, firewalls, IAM, and hardware-level monitoring.
• Experience with at least one IaC/configuration management tool applicable to bare-metal or private clouds (e.g. Terraform, Ansible, SaltStack, Puppet)
• Solid scripting / programming skills for automation (e.g. Python/Bash/PowerShell)
• Strong understanding of application architectures, container orchestration (e.g., Kubernetes, OpenShift), and the ability to read and reason about code to debug platform issues
• Experience implementing strict security best practices in air-gapped or highly regulated environments following industry standards and compliance
• Fluency in both Finnish and English (written & spoken)
• Willingness to work 100% on-site
• This position requires Finnish citizenship due to client and security regulations. The selected candidate must successfully complete a security clearance process.
• Strong CI/CD experience (e.g. GitLab CI, Jenkins, GitHub Enterprise Server or similar)
• Practical experience with self-hosted observability stacks (e.g. Prometheus, Grafana, ELK/Opensearch)
• Customer oriented mindset, with experience in partnering closely with clients/ stakeholders.

For two decades, we’ve been developing qualities and capabilities for adapting, reacting, and supporting change – building Reaktor to hold up in a fast-paced environment while ensuring the well-being of our people.

While working at Reaktor, we’ll provide you with: