Senior 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.

Your daily tasks include:

Designing, implementing and maintaining modern on-premise and private cloud environments, including GPU-enabled infrastructure for AI workloads, to help product teams deliver high-quality solutions.

Making sure security, isolation, and compliance are built into everything you create.

Enabling scalable and resilient infrastructure that can grow with demand and keep the digital services running reliably on physical hardware and virtualization layers.

Automating as many routine tasks as possible to free up engineers time to focus on higher-value work.

Promoting standardization through common tools, processes and configurations to reduce complexity, improve maintainability, and accelerate development cycles.

Acting as a trusted advisor by working closely with product t