Senior Fullstack Developer

Job title: Senior Fullstack Developer

About the Role

Reaktor's Amsterdam tech community is seeking an experienced Senior Fullstack Developer to join one of our Business Units in Amsterdam. You will be hands-on across modern web applications, backend services and production systems, solving ambiguous problems with clients, and helping shape technical decisions in a low-hierarchy environment. You will support clients across a range of digital product, platform and service domains, with varied contexts from focused product teams to high-traffic, business-critical services.

What You'll Do

• Build and improve modern web applications, backend services, APIs and data models

• Work across frontend, backend and infrastructure depending on client project needs

• Help clients choose suitable technologies, architecture and delivery approaches

• Contribute to cloud environments, CI/CD pipelines, deployments and production operations

• Debug, test, monitor and improve production-grade systems

• Work on products or tooling related to customer-facing services, internal platforms, identity, martech, customer support, analytics, content, online stores, integrations, developer tooling or SDKs

• Collaborate directly with client tech teams, business stakeholders, designers, product people and other disciplines

• Clarify ambiguous requirements and turn them into working software

• Take responsibility for delivery while making sure the team is supported and no one is left behind

• Use modern development practices, including openness to AI-assisted development tools and workflows

• What We're Looking For

• 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 this level usually takes several years of professional experience to build.

• Nice to Have

• 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

• Compensation & Benefits At Reaktor Amsterdam, our benefits and perks evolve with our community, and we’re always open to new ideas that will support the wellbeing of Reaktorians. Currently, we offer the following perks:

• Tools: top-spec computer and a phone to work with and use at work and home; additional tools if needed

• Phone & internet: unlimited phone plan and a proper internet connection to your home

• 7% pension plan: on top of your annual income, with option to contribute extra directly from your gross salary

• Extensive health insurance: through CZ; we cover the entire HI premium and reimburse the eigen risico; alternatives available

• Mental health support: with Reaktor's Hug team and OpenUp

• Wellbeing benefit: YourCampus with a personalized benefit package

• Commuting benefit: NS business card

• We are an equal opportunity employer; all applicants will be considered without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, veteran or disability status.