---
title: 'Senior Fullstack Developer at Reaktor'
canonical: 'https://feeny.ai/job/senior-fullstack-developer-reaktor-amsterdam-fnev0zr951jj'
type: 'job'
last_seen: '2026-09-05'
---

# Senior Fullstack Developer at Reaktor

- **Company:** Reaktor
- **Location:** Amsterdam, Netherlands
- **Employment:** full-time
- **Work type:** hybrid
- **Posted:** 2026-07-03
- **Last confirmed live:** 2026-09-05
- **Apply:** https://jobs.ashbyhq.com/reaktor/6f7d17e8-dd95-43b1-bc25-64d550e7e38f

## Job description

Reaktor's tech community is looking for an experienced Senior Fullstack Developer to join one of our Business Units in Amsterdam.

If you are comfortable working across modern web applications, backend services and production systems, enjoy solving ambiguous problems with clients, and are curious to work in a low-hierarchy environment, you might just be what we’re looking for.

You will support clients across a range of digital product, platform and service domains. The exact client context may vary from focused product teams to large international companies working on high-traffic, business-critical services.

Many of our clients are technically mature and expect a high level of expertise from our consultants. This means you will need to be hands-on, pragmatic and comfortable helping both the client and the team make good technical decisions.

## YOUR DAILY TASKS MAY INCLUDE:

- Building and improving modern web applications, backend services, APIs and data models
- Working across frontend, backend and infrastructure depending on the needs of the client project
- Helping clients choose suitable technologies, architecture and delivery approaches
- Contributing to cloud environments, CI/CD pipelines, deployments and production operations
- Debugging, testing, monitoring and improving production-grade systems
- Working on products or tooling related to customer-facing services, internal platforms, identity, martech, customer support, analytics, content, online stores, integrations, developer tooling or SDKs
- Collaborating directly with client tech teams, business stakeholders, designers, product people and other disciplines
- Clarifying ambiguous requirements and turning them into working software
- Taking responsibility for delivery while making sure the team is supported and no one is left behind
- Using modern development practices, including openness to AI-assisted development tools and workflows

TO THRIVE IN THIS POSITION, YOU’LL NEED:

## MUST-HAVES

- Strong experience in modern frontend development, for example with TypeScript and React or comparable technologies
- Strong experience in backend service development, for example with Node.js, Java, Kotlin, Python or comparable technologies
- Experience building, shipping and improving production-grade digital products
- Comfortable working across the full delivery lifecycle, from implementation to testing, deployment and production operations
- Understanding of cloud environments, CI/CD, deployments and how production systems are operated
- Ability to work directly with clients, stakeholders and other disciplines in a senior, consultative role
- Strong problem-solving skills and the ability to bring clarity to ambiguous product or technical situations
- A hands-on mindset — you are technically credible, actively contribute to the work and help the team move forward
- Fluent verbal and written English skills to collaborate in an international environment

We do not have a hard requirement around years of experience, but we have noticed that this level of fullstack, client-facing and production ownership usually takes several years of professional experience to build.

## NICE-TO-HAVES

- Experience from customer-facing digital products, online services, ecommerce, subscriptions, internal platforms, analytics, content, martech or similar product domains
- Experience with high-traffic or business-critical production systems
- Deeper experience with platform engineering, infrastructure-as-code or DevOps practices
- Experience with customer-facing products, internal tools, integrations, SDKs or developer tooling
- Familiarity with mobile development

## ADAPTABILITY

Willingness to work in a hybrid setup. This means balancing office, client premises and remote work depending on the client project and team needs.

## 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

- [Machine Learning Engineer](https://feeny.ai/job/machine-learning-engineer-reaktor-helsinki-0nt2f0pa5t2c) — Helsinki, Finland
- [Cross Platform - iOS and Android | Retail](https://feeny.ai/job/cross-platform-ios-and-android-retail-reaktor-helsinki-g9j3fzmzrc39) — Helsinki, Finland
- [AI Developer - LLM Applications](https://feeny.ai/job/ai-developer-llm-applications-reaktor-helsinki-hb6354vrjmcj) — Helsinki, Finland
- [Head of Communications & Investor Relations, Global](https://feeny.ai/job/head-of-communications-investor-relations-global-reaktor-helsinki-rcm4d5mn8pys) — Helsinki, Finland
- [Head of Marketing, Global](https://feeny.ai/job/head-of-marketing-global-reaktor-helsinki-hggdvqdatkxw) — Helsinki, Finland
- [Mobile Developer](https://feeny.ai/job/mobile-developer-reaktor-helsinki-93yw2vyr6axd) — Helsinki, Finland
- [Product Management Lead, Retail](https://feeny.ai/job/product-management-lead-retail-reaktor-amsterdam-a1ceagp3jzek) — Amsterdam, Netherlands
- [Senior Fullstack Developer](https://feeny.ai/job/senior-fullstack-developer-reaktor-helsinki-xqkv56tjdmq3) — Helsinki, Finland
- [Senior Fullstack Developer](https://feeny.ai/job/senior-fullstack-developer-reaktor-lisbon-er4gb7vwnwzc) — Lisbon, Portugal
- [Business Development Specialist](https://feeny.ai/job/business-development-specialist-reaktor-helsinki-btr7j41wvf0d) — Helsinki, Finland