Full Stack Backend Developer, Rotterdam

Voor onze eindklant KPN is Harvey Nash op zoek naar een Full Stack Backend Developer

Start: 01-12-2025

Eind: 01-06-2026

Standplaats: Rotterdam

Uren: 36

Deadline inschrijven: 17-11 om 17:00

Team KPN Developer Portal is looking for a new hands-on and eager-to-learn colleague! Do you have a passion for innovation and technology, and are you flexible and a team player? Then read on...

About Us:

The Developer Portal team is end-to-end responsible for the distribution and delivery of developer products to KPN and its customers, suppliers, and partners. It’s an international team where English is the working language.

The entire team works from the Rotterdam office two days a week. The team follows the Agile/Scrum methodology, values autonomy, and places high importance on trust, humor, and responsibility.

The team consists of 13 people with a wide range of expertise: front-end developers, API specialists, OPS/Infra (AWS), and backend developers.

We are looking for someone with:

• 5+ years of professional software development experience
• Strong knowledge of OOP, clean code, SOLID principles, and design patterns
• Experience with microservices, event-driven architecture, and async messaging
• Experience with CI/CD pipelines and Infrastructure as Code (IaC)
• Good knowledge of RESTful APIs, OpenAPI/Swagger, and OAuth2
• Experience with Docker and containerized workflows
• Understanding of security best practices and observability
• A team player with ownership and strong communication skills

Tech skills:

.NET Core (C#) Stack – Must-have:

• C# 10 or higher, .NET 6–9
• ASP.NET Core Web API
• YARP
• Dependency Injection, Middleware, Filters
• Async programming
• Entity Framework Core or Dapper
• Unit and integration testing (xUnit, FluentAssertions)
• Logging, Tracing, Monitoring
• OAuth2, API versioning, rate limiting, model validation
• Knowledge of OpenAPI specification

Python / Django Stack – Must-have:

• Python 3.9+
• Django + Django REST Framework
• ORM (Django ORM or SQLAlchemy)
• Celery / Redis for background tasks
• OAuth2 authentication
• pytest / unittest
• Kubernetes
• Logging (Sentry)
• Knowledge of REST API best practices

Nice-to-have:

• Orleans (virtual actor model / grains)
• Event-driven patterns with NATS / SNS / SQS
• ClickHouse integration for analytics
• Redis caching
• ECS Fargate deployments
• AWS CDK (TypeScript) for infrastructure

AWS Cloud-native Skills:

• AWS Lambda (serverless microservices, event handlers)
• AWS ECS (Fargate) for containerized workloads
• AWS DynamoDB (partitions, indexes, TTL, stream triggers)
• AWS CDK (TypeScript) – IaC design, stacks, construct libraries
• S3, CloudWatch, IAM, API Gateway, Secrets Manager
• CloudFormation and stack deployments
• Monitoring and tracing (X-Ray, OpenTelemetry, CloudWatch Logs)
• Event-driven flows (EventBridge, SNS/SQS/NATS integration)

Data & Messaging:

• ClickHouse: query performance, schema design, materialized views
• NATS JetStream: publish/subscribe, stream management, durability
• Redis: caching and rate-limiting
• DynamoDB: schema design, partition/sort keys, secondary indexes

DevOps & Tooling:

• CI/CD pipelines (GitHub Actions, Bitbucket)
• Docker Compose/Aspire for local development
• Observability with OpenTelemetry, Serilog, Prometheus, Grafana
• Secrets management (AWS Secrets Manager / Parameter Store)
• Git, branching strategies, code reviews
• Linting, code quality tools

Soft skills:

• Ownership: taking end-to-end responsibility
• Mentoring juniors or peers
• Able to independently design, implement, and deploy features
• Strong communicator, clear code reviews
• Able to contribute technically at the architectural level

Does this sound like a match, and do you tick (a lot) of these boxes? Don’t hesitate to get in touch—we’d love to meet you!