---
title: 'Senior Platform Engineer (Defence & Security) at Reaktor'
canonical: 'https://feeny.ai/job/senior-platform-engineer-defence-security-reaktor-helsinki-dtwtntx0xmnd'
type: 'job'
last_seen: '2026-11-07'
---

# Senior Platform Engineer (Defence & Security) at Reaktor

- **Company:** Reaktor
- **Location:** Helsinki, Finland
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-10-30
- **Last confirmed live:** 2026-11-07
- **Apply:** https://jobs.ashbyhq.com/Reaktor/19162bf3-7ca9-4f72-871f-f1546f6a401e

## Job description

Reaktor’s tech community is looking for a Senior Platform Engineer to join our Defence & Security Business Unit in Helsinki. Our [Defence & Security Unit](https://www.reaktor.com/industries/defense-and-security) 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 teams and other stakeholders to understand the requirements and provide the infrastructure support they need.

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

What we are looking for:

- Hands-on experience in platform/infra/DevOps roles. We don’t have a hard limit on years of experience, but we’ve noticed that these competencies often take 8+ years to accumulate.
- Deep expertise in on-premise and/or bare-metal infrastructure, including virtualization platforms (e.g., VMware vSphere, KVM, OpenStack), physical hardware, and hardware-level monitoring.
- Solid infrastructure automation skills combining IaC/configuration management tools (e.g., Terraform, Ansible, SaltStack, Puppet) with hands-on scripting/programming (e.g., Python, Bash, PowerShell) for private clouds and bare-metal.
- Strong understanding of container orchestration (e.g., Kubernetes, OpenShift) and modern application architectures, with the ability to read and reason about application code to debug platform-level issues.
- Experience with enterprise networking, firewalls, IAM, and 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% onsite.
- This position requires Finnish citizenship due to client and security regulations. The selected candidate must successfully complete a security clearance process.

Nice-to-have skills:

- 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).
- Practical skills in Backend development.
- Experience in partnering closely with clients/ business stakeholders.

Why join us? 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:

- The ability to impact how you work. Together with the client, your team chooses the approach, technologies, and methodologies you think will work best in any given situation
- A community with as much support as your heart desires
- A team that’s not only experienced but considerate as well – they all want you to succeed
- A sustainable work-life balance and support for your daily life outside of work. (e.g., free moving day, Reaktor car share, sick child care services, office space to use for your private events, etc.)
- An opportunity to grow as a professional. In addition to the day-to-day work, we offer internal training courses, community events to discuss hot topics in tech and design
- Many different hobby clubs, from winter swimming and running to knitting and archery, that bring people together outside of (and sometimes inside) office hours. Many of these are supported by Reaktor

Diversity, equity, and inclusion Together, we are committed to making Reaktor an environment that embraces and values all of our employees for the whole of who they are. We encourage applicants from all backgrounds to apply, knowing that studies show that members of underrepresented communities don’t apply for jobs unless they fully satisfy all of the requirements. If you're thinking twice about applying for this reason, we invite you to send us your application anyway. You could be just the person we're looking for. Read more about our DEI work here.

## About Reaktor

## Company Overview
- **One-liner**: Reaktor is a global technology company that designs and builds category-defining digital solutions across industries, from software development and strategic design to AI and data capabilities.
- **Entity Type**: Private (pre-IPO; planning a listing on Nasdaq Helsinki)
- **Headquarters**: Helsinki, Finland
- **Founded**: 2000
- **Founders**: Not publicly listed

## Core Business
- Primary industries: aerospace & defense, finance, healthcare, industrial, gaming, retail, public sector
- Target customers: large enterprises, government agencies, and high-stakes organizations (B2B, predominantly enterprise)
- Mission / purpose: Create category-defining products that perform when it matters most, driven by a “Culture of Better” – iterative improvement, autonomy, and deep domain expertise

## Products & Services
- **Custom Solutions**: Embedded engineering, design, and strategy teams that partner with clients on mission-critical technology challenges. 97% net revenue retention (2025) and DORA scores 7.5–16% above industry average.
- **Productized Solutions**: Ready-made software products built from 25 years of domain knowledge, already deployed in defense and security markets.
- **Reaktor Ecosystem**: A network of >45 independently operating technology companies that Reaktor invests in or co-founds, providing engineering credibility, domain expertise, and a two‑decade network.

## Market Standing
- **Valuation / Market Cap**: Not disclosed (private pre-IPO)
- **Key Metric**: Estimated annual revenue of ~€190 million (based on company‑stated figures; exact numbers not confirmed in public filings)
- **Notable Investors/Partners**: No external venture investors; partners include ABB, ZAP Surgical Systems, and others across industries.
- **Growth Signals**: Planning an IPO on Nasdaq Helsinki; headcount of 700+ professionals across 9 offices on 3 continents; 58 nationalities; expanding productized software and AI/Data offerings; strong retention and quality metrics.

## Competitive Advantages
- Deep industry specialization (aero, defense, finance, healthcare, etc.) rather than generalist consulting
- 25 years of Nordic‑rooted agile practices and a culture of autonomy and continuous learning
- Full lifecycle partnerships – from problem identification to design, development, and long‑term maintenance
- Productized approach that turns accumulated domain expertise into scalable, reusable software
- Ecosystem model that extends reach and innovation capacity beyond a single firm

## Strategic Focus
- Initial Public Offering on Nasdaq Helsinki to accelerate growth and increase market visibility
- Growth of productized software business, especially in defense & security and other high‑stakes verticals
- Deepening AI and data capabilities (e.g., LLM applications, AI developers) integrated into every client engagement
- Continued expansion of the Reaktor Ecosystem through co‑founding and investing in independent technology companies

## Why Work Here
- **Culture**: “Culture of Better” – people‑first, Nordic values of trust, autonomy, and continuous improvement. 58 nationalities in a global, collaborative environment.
- **Work Model**: Hybrid; team‑specific agreements on on‑site vs. remote work depending on client and project needs.
- **Perks**: Minimum 25 vacation days, top‑class health benefits (including mental health support and ergonomic solutions), professional growth programs (mentoring, internal academies, external courses/books budget), 200+ hobby clubs, relocation support, latest tech equipment.
- **Growth**: Six‑month onboarding, strong emphasis on learning and mastery; opportunities to work on challenging, high‑impact projects across industries.
- **Autonomy**: Cross‑functional teams have freedom to choose tools, methodologies, and tech stacks.

## Sources
1. [reaktor.com – About](https://www.reaktor.com/about-us)
2. [reaktor.com – Careers](https://www.reaktor.com/careers)
3. [reaktor.com – Culture](https://www.reaktor.com/culture)
4. [reaktor.com – All Open Positions](https://www.reaktor.com/careers/all-open-positions)

## Other roles at Reaktor

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