Senior Fullstack Developer

Reaktor

Senior Fullstack Developer building modern web applications and backend services for Reaktor's clients in Amsterdam. Collaborating with stakeholders and using AI-assisted development tools in a hybrid setup.

Posted 7/3/2026full-timeAmsterdam • 🇳🇱 NetherlandsSeniorWebsite

Tech Stack

Tools & technologies

CloudJavaJavaScriptKotlinNode.jsPythonReactTypeScript

About the role

Key responsibilities & impact

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

Requirements

What you’ll need

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

Benefits

Comp & perks

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.

ATS Keywords

✓ Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills & Tools

TypeScriptReactNode.jsJavaKotlinPythonProduction-Grade Digital ProductsTestingDeploymentDebugging

Soft Skills

Problem-SolvingHands-On MindsetCollaborationClarity in Ambiguous Situations