30.10.2026 aktualisiert

**** ******** ****
Premiumkunde
100 % verfügbar

Java/Kotlin expert, software architect and interim CTO

Berlin, Deutschland
Berlin +500 km
Dipl. Inf. Medieninformatik
Berlin, Deutschland
Berlin +500 km
Dipl. Inf. Medieninformatik

Profilanlagen

2026_08_EN_SBeuster_Freelance.pdf

Skills

KeycloakAI AgentsFlutterJavaPostgreSQLAWS CLIWorkflow-Management-SystemeSpring BootBackendKotlin
I provide the following services
  • Software Development
  • Backend: Java, Kotlin
  • Mobile: Flutter, Kotlin
  • Design and implementation of complete system architectures,
  • Consulting and and implementation of transitions to Cloud architectures (mostly AWS),
  • setup and scaling of lean and pragmatic development teams
My project history only covers the last ten years. Please consult my CV for the full picture.

Erfahrung

Berufserfahrungmehr als 10 Jahre
Freelancer seit2020

Sprachen

DeutschMutterspracheEnglischverhandlungssicher

Projekthistorie

Allunity.com - Backend Development and Consulting

Allunity GmbH

Banken und Finanzdienstleistungen

10-50 Mitarbeiter

Work:
  • Implementation of a Bafin regulated Stable Coin platform.
  • Domain modelling, API Development, Integration of Spring Security (JWT based, internal/external)
  • Compliance-driven architecture with auditability and fault tolerance
Tech Stack:
  • Java (21) / Kotlin, Spring (Spring Security, Oauth2), Gradle
  • PostgreSQL, Kubernetes, Python, Keycloak,
  • Payment APIs (Banking Circle, etc.),
  • Temporal.io (workflow engine)





Mediamarkt Saturn - Backend Development and Consulting

Mediamarkt Saturn

Internet und Informationstechnologie

>10.000 Mitarbeiter

  • Development of MediaMarkt’s customer order management system (COS) for all European MediaMarkt Online branches.
  • Technology Stack: Java (21) /Kotlin, Kafka, PostgreSQL, Kubernetes, Google Cloud, Grafana, Spring Boot, Temporal (durable workflow engine)

Backend - Development and Consulting - Tooltime GmbH

Tooltime GmbH

Internet und Informationstechnologie

50-250 Mitarbeiter

I developed the backend pieces of multiple Tooltime.de capabilities and features
- Aggregation of search engine results,
- API interoperability to partnership companies of Tooltime,
- Implementation of Tooltime's new measurement feature, enabling better project and resource planing for Tooltime's customers
- etc.

Tech stack: Kotlin/Java, PostgreSQL, ElasticSearch, AWS, GraphQL, Spring Boot

Backend - Development and Consulting - Aurubis AG

azeti GmbH / Aurubis AG

Industrie und Maschinenbau

1000-5000 Mitarbeiter

I participated in the development of a new material and resource management system for Germanies largest precious metal producer, Aurubis AG.

Further details can be discussed upon request.

Tech:
- Java (11),
- Kotlin,
- Microsoft Azure,
- Kubernetes,
- PostgreSQL,
- Apache Kafka,
- Docker

Backend - Development and Consulting - Porsche Digital

Porsche Digital

Automobil und Fahrzeugbau

>10.000 Mitarbeiter

Consulting and development on a manufacturing optimization project for the Porsche AG - Leipzig.

Tech:
- OptaPlanner,
- Java (11),
- Kotlin,
- AWS (Fargate, RDS, AmazonMQ),
- Docker

Interim CTO - smart Helios

smart Helios GmbH

Pharma und Medizintechnik

10-50 Mitarbeiter

Smart Helios (now “curalie” GmbH) is a subsidiary of Helios clinics Germany. Its mission is to explore digital opportunities and products within the fast-changing health care sector. It was my responsibility to
  • oversee the design and implementation of smart Helios’ first app – a system to monitor symptoms of cancer patients while in therapy which leads to improved quality of life and higher life expectancy,
  • consolidate existing IT projects, reduce distractions and lower operational costs,
  • recruit our tech team and mentor talents,
  • improve our agile development methodology for better predictability and results.

Tech: 
- Java (11) / Kotlin,
- SpringBoot,
- AWS (RDS, Fargate, Cloudfront),
- Docker,
- ReactJS, React Native,
- Github

CTO in residence - Finleap / Valendo

Finleap

Internet und Informationstechnologie

50-250 Mitarbeiter

Valendo, a Finleap venture, offers financing solutions to small and medium enterprises using inventory assets and goods as collateral. In my time as lead developer and CTO I oversaw
  • the ideation of the business problem into a first technical design and prototype,
  • the completion of a reliable data warehouse that evaluates goods and assets in near-real-time.
The result was a secure, reliable and cost-efficient cloud-based data pipeline that provided decision makers with quick analysis of risk exposure and business insights

Gymondo GmbH - CTO

Gymondo GmbH

Medien und Verlage

50-250 Mitarbeiter

Kontaktanfrage

Einloggen & anfragen.

Das Kontaktformular ist nur für eingeloggte Nutzer verfügbar.

RegistrierenAnmelden