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Backend development that is reviewed and runs in production.

Kotlin, Java and AWS – with AI for speed and an experienced engineer for architecture, review and accountability. I support your team wherever it needs reinforcement right now.

01

Backend development with Kotlin and Java

New services and extensions to existing systems – with clean interfaces, well-designed data models and tests that genuinely protect something.

Example: PDF generation in microservice landscapes →
Typical tasks
  • New microservices and REST APIs
  • Spring Boot, Spring Data and Hibernate
  • Databases such as PostgreSQL
  • Test automation with JUnit, Testcontainers and Rest Assured
02

AWS and event-driven architecture

Systems that communicate via queues and topics scale well – if the details are right. I design and build such solutions on AWS.

Example: extended clients for Kotlin →
Typical tasks
  • Messaging with Amazon SQS and SNS
  • Offloading large messages to S3 (claim-check pattern)
  • Integration with existing AWS landscapes
  • Integration tests against a local AWS emulator
03

Modernizing existing systems

Bringing older systems up to date step by step without putting operations at risk – with clear decisions instead of mechanical translation.

Typical tasks
  • Migrating Java code to Kotlin
  • Replacing dependencies that carry security advisories
  • License review of the libraries in use
  • Validating technology choices with prototypes
04

AI-assisted development

AI writes code fast. Reviewing, deciding and taking responsibility is a human’s job. That is exactly the split I bring to your project.

Example: three libraries, built with AI assistance →
Typical tasks
  • AI writes code, tests and boilerplate to clear specifications
  • I define the architecture and review every change
  • License review, tests and traceable releases
  • Introducing AI workflows to your team
Technologies
  • Kotlin
  • Java
  • Spring Boot
  • Spring Data
  • Hibernate
  • aws-sdk-kotlin
  • Amazon SQS
  • Amazon SNS
  • Amazon S3
  • PostgreSQL
  • Docker
  • Docker Compose
  • Testcontainers
  • JUnit
  • Rest Assured
  • Gradle
  • Maven
Contact

Let’s talk about your backend.

Drop me a short note about what you need. I’ll get back to you personally, and together we’ll find out whether and how I can help.

contact@christoph-sens.comGitHub
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Christoph SensYour direct point of contact