Fullstack Developer

The Full-Stack Developer is a web engineer or web developer that deals with the front-end and back-end (and everything in-between) of an application or website. The Full-Stack Developer can work with any stack—mobile, web, or native applications. The Full-Stack Developer writes both front-end and back-end code; designs user interfaces on web pages; creates databases and servers for functionality; ensures cross-platform optimization (e.g., laptops, tablets, smartphones); has a high-level understanding of the organization’s systems and processes; detects errors in the front or back ends; maintains good communication with the UI/UX Developer and other team members regarding matters such as user-experience issues and design rationale; and oversees a development project from start to finish.

Role Overview

As a Senior Full-stacker with focus on back-end in the OSI team, you will design and deliver scalable, production-ready backend solutions that enable accurate customer offerings. Using .NET and Azure, you’ll build cloud-native and event-driven systems that drive innovation and business impact. You’ll collaborate closely with developers and stakeholders, contributing across the stack with a hands-on, pragmatic approach. The team, described as a team with an open working culture, currently consists of 6-7 other developers which will grow on the short term.

Key Responsibilities

• Design, build, and maintain backend services using .NET on Azure
• Write clean, maintainable, and well-tested code with proper documentation
• Make informed technical decisions (performance, scalability, cost, reliability)
• Implement event-driven architectures for efficient system communication
• Own features end-to-end: discovery, design, development, testing, deployment, and monitoring
• Share best practices in code quality, security, and performance
• Collaborate with cross-functional teams to deliver complete solutions

You’ll also contribute to architectural decisions, balancing business needs with technical excellence, and ensuring solutions are secure, scalable, and future-proof.

About You

• 5+ years of development experience, focus on back-end
• Strong expertise in .NET Core and C#, knowledge of Angular or similar framework
• Hands-on experience with Azure (e.g., Functions, Service Bus, Event Grid, Key Vault, App Insights, Container Apps)
• Experience with event-driven architectures and messaging systems (e.g., Kafka)
• Familiar with Infrastructure as Code, CI/CD pipelines, and containers (Docker/Kubernetes)

Key Strengths

• Clear and proactive communication with technical/non-technical stakeholders
• Strong focus on code quality, security, and performance
• Collaborative mindset with DevOps and frontend teams
• Curiosity and creativity in applying new technologies such as working with Copilot/Cursor and agentic AI in general
• Commitment to building impactful, future-oriented solutions

Work experience in the energy sector is preferred but not mandatory.

• Office presence (Amsterdam) is needed on 1 or 2 days per week. This is often on Wednesday but can be discussed within the team.
• CVs can be submitted in Dutch and English.
• Dutch speaking is required for this position.