Mid/Senior Backend Developer - C#/.NET

Keytrade Bank is a young and dynamic bank where IT systems were traditionally developed in-house. Today, we are evolving towards a model focused on customer experience and innovation, combining in-house solutions with off-the-shelf products and services for core functionalities. Where responsibilities used to be organized by technical skills, we now structure them by business domain, called Feature Teams. Building new products requires close collaboration across back-end, front-end, database, infrastructure, vendors, and service providers. Working in a smaller bank means broader responsibilities, wider knowledge, and the opportunity to make a real impact. We are growing fast and are looking for motivated people eager to join our teams to help transform and improve our trading and banking systems. What makes the position interesting? You will work on a distributed .NET platform built around C# / .NET, Domain-Driven Design and event-driven microservices. Our services communicate through gRPC and asynchronous messaging using RabbitMQ and NServiceBus, applying patterns such as CQRS, Domain Events, Outbox, etc. You will be involved not only in development, but also in domain modelling, technical design, architecture decisions and the continuous evolution of our distributed systems. The platform runs on AWS and Kubernetes (EKS) and uses MySQL/Aurora and DynamoDB, depending on the domain and its access patterns. We put a strong emphasis on engineering quality, automated testing, observability and production readiness. Infrastructure and delivery are managed through GitLab CI/CD, Docker, Kubernetes and Terraform. The role offers the opportunity to work on real-world distributed systems where reliability, scalability, maintainability and domain complexity matter, rather than simply building CRUD applications. You will not only work with interesting technologies, but also solve complex problems across three key business domains: Banking – everything related to payments and banking transactions. Cards – debit and credit card ordering and management. Credits – primarily our online mortgage product, Keyhome. Profile You are a passionate developer who enjoys: Being a true team player, sharing knowledge and supporting colleagues, while also being able to drive initiatives autonomously. Transforming complex business needs into elegant and maintainable technical solutions. Balancing engineering discipline with pragmatism. Caring deeply about code quality, security and maintainability. Continuously learning, both from a technical perspective and about the banking domain. Participating in technical design, domain modelling, architecture decisions and the evolution of distributed systems. Working in a Scrum environment. Our working environment is mainly English-speaking, and you are fluent in English. Dutch and French are considered an asset but are not mandatory. As an experienced .NET/C# developer, you have solid experience with: C# / .NET 8/.NET 10 Domain-Driven Design (DDD) REST API: consuming, designing and building APIs Messaging/Event-driven architecture: commands, events, asynchronous communication RabbitMQ Clean Code and SOLID principles Microservices architecture Distributed systems: idempotency, retries, failure handling Automated testing: unit and integration testing, TDD, xUnit, Moq, AutoFixture Containerization – Docker Relational Database, transactions, queries and ORM We also use these technologies, and we would appreciate if you master them, but if you do not have experience with them, we will help you get up to speed with them: NServiceBus Kafka Amazon Web Services (S3, DynamoDB, KMS, Api Gateway, EKS…) gRPC/protobuf OpenTelemetry Serilog Dynatrace Terraform GitLab CI/CD Offer Hybrid way of working: 50% office / 50% home workingAgile way of workingGreen surroundingsAn inclusive workplace with nice colleaguesA competitive salary package with advantages such as:Meal vouchers: €10 / working dayTeleworking allowanceTransport allowanceGroup insuranceHospitalisation insurance