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; 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.

Skills:    
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
Education:    
Work experience in the energy sector is preferred but not mandatory.
Practical information:

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