.NET Backend Developer

S4D; Amsterdam; On-site; EUR 60,000 - 90,000; Full time

Job summary

S4D is seeking a skilled .NET Backend Developer to own core backend features, write high-quality C# code, and deploy resilient microservices across cloud platforms.

You will collaborate with senior engineers, participate in peer code reviews, and continuously improve our codebase while leveraging AI tooling to accelerate development.

Qualifications

• 3+ years of backend software engineering experience with C#/.NET Core.
• Proven experience delivering RESTful APIs or microservices to production.
• Experience with message queues or event brokers (Azure Service Bus, MassTransit, RabbitMQ, Kafka).
• Practical familiarity with core Azure services and cloud-native concepts.
• Experience with automated unit testing (xUnit, NUnit) and clean code (SOLID, DRY).
• Strong communication and a collaborative mindset with the team.

Responsibilities

• Own backend services across feature lifecycles, from implementation to deployment and monitoring.
• Develop clean, modular C# code for modern .NET Core runtimes using established patterns.
• Build and maintain event-driven workflows with Azure Service Bus and MassTransit.
• Write unit/integration tests and participate in CI workflows for performance optimization.
• Participate in code reviews and share knowledge with peers and seniors.
• Leverage AI tooling to boost productivity, test cases, and debugging.

Skills

C#

.NET Core

RESTful APIs

Message queues

Azure Cloud

Unit testing

SOLID/DRY

Communication

3+ years backend

Tools

Azure Service Bus

MassTransit

RabbitMQ

Kafka

SQL Server/EF Core

Azure DevOps

GitHub Actions

Job description

About the Company

S4D is a Software as Service (SaaS) company that provides Quick Service Restaurants (QSRs) with the omnichannel operating system to run their business in the most effective and efficient way. In other words, we help restaurants to get more orders. Our team builds and services innovative products based on the newest technologies, consisting of a wide variety of functionalities and innovative modules while offering our employees flexible working conditions. Our key values are teamwork and ownership. S4D is part of the Deloitte Technology Fast 50 and Saas100 company (selected by MT/Sprout).

About the Role

We are looking for a .NET Backend Developer with 3+ years of experience who combines solid software engineering practices with a passion for building reliable cloud systems. In this role, you will take ownership of core backend features - contributing to solution design, writing high-quality C# code, and deploying resilient microservices across our cloud platforms.

You will collaborate closely with senior engineers and team members to maintain high technical standards, participate in peer code reviews, and continuously improve our codebase.

We also encourage our engineers to utilize modern AI developer tools (such as Cursor or Claude Code) to accelerate daily workflows and streamline problem-solving.

Responsibilities

• Feature Ownership: Take ownership of backend services across feature lifecycles- from technical implementation and testing to deployment and operational monitoring.

• Service Development: Write clean, modular, and maintainable C# code targeting modern .NET Core runtimes, adhering to established architectural patterns.

• Asynchronous Messaging: Build and maintain reliable integrations and event-driven workflows using Azure Service Bus and MassTransit.

• Quality & Testing: Write comprehensive unit and integration tests, actively participate in continuous integration workflows, and optimize application performance.

• Collaborative Engineering: Participate in constructive code reviews, share technical knowledge with peers, and contribute to technical design discussions alongside senior team members.

• AI-Assisted Workflows: Leverage modern AI coding tools to boost productivity, write test cases, and troubleshoot complex bugs effectively.

What You Bring (Mandatory)

• 3+ years of hands-on backend software engineering experience with C# and .NET Core.

• Solid Feature Delivery: Proven experience building and shipping RESTful APIs or microservices to production environments.

• Messaging & Event-Driven Patterns: Practical experience with message queues or event brokers (e.g., Azure Service Bus, MassTransit, RabbitMQ, or Kafka).

• Azure Cloud Experience: Practical familiarity with core Microsoft Azure services and cloud-native concepts.

• Testing & Quality Mindset: Experience with automated unit testing (e.g., xUnit, NUnit) and a strong commitment to clean code principles (SOLID, DRY).

• Collaborative Mindset: Strong communication skills and a desire to contribute in an open, feedback-driven engineering environment.

• Location & Work Authorization: Must be currently residing in the Netherlands and hold a valid, unrestricted working permit.

Nice-to-Haves

• Direct experience with Event driven patterns in production.

• Familiarity with containerization (Docker, Kubernetes).

• Hands-on experience writing relational database queries and working with SQL Server / Entity Framework Core.

• Experience working with modern CI/CD pipelines (Azure DevOps or GitHub Actions).

• Exposure to legacy system migration projects (.NET Framework to modern .NET).

• Experience incorporating developer AI tooling (e.g., Cursor, Claude Code) into your daily development routine.