Freelance Software Developer
Aktualisiert am 24.01.2025
Profil
Freiberufler / Selbstständiger
Remote-Arbeit
Verfügbar ab: 01.02.2025
Verfügbar zu: 100%
davon vor Ort: 5%
Fullstack
Java
Spring Boot
Go
Kubernetes
AWS
Azure
Docker
CI/CD
German
English
Czech

Einsatzorte

Einsatzorte

Hamburg (+50km)
Deutschland, Schweiz, Österreich
möglich

Projekte

Projekte

1 year
2024-01 - 2024-12

Greenfield project

Technical Lead
Technical Lead
Greenfield project  building an EdTech platform for students. The backend is designed as a serverless architecture in which functions are executed using the Go programming language and communicate with a MongoDB database. The frontend is a classic React application.
on Request
1 year 1 month
2023-01 - 2024-01

Backend Development

Senior Backend Developer
Senior Backend Developer
Further development of an existing microservice architecture with different technologies. Kotlin, Golang and C#.NET were used. Communication between the services took place asynchronously via Kafka. The existing frontend was tested automatically using Selenium to test the entirety of the business logic.

yourIT GmbH
11 months
2022-01 - 2022-11

Development of a complex gateway service

Senior Java Backend Developer
Senior Java Backend Developer
Further development of a complex gateway service for processing credit card transactions. Java was used in the backend with Spring Boot. The challenge was the complexity of the transactions and the fast transaction processing. Deployment took place on the Azure Cloud with an AKS cluster.

Lufthansa Airplus GmbH
7 months
2021-06 - 2021-12

Development of a cloud native PIM (Product Information Management) application

Python Backend Developer
Python Backend Developer
Further development of a cloud native PIM (Product Information Management) application, using Python as the programming language. The PIM was not implemented as a traditional backend, but ran purely as AWS Lambda functions. In addition, my role was to coordinate with product partners (national / international).

Galeria
8 months
2020-11 - 2021-06

Construction of a prototype to extend the test framework at Bentley

Kotlin Developer
Kotlin Developer
Construction of a prototype to extend the test framework at Bentley. This involved developing small test services to simulate business logic. Kotlin and Golang were used. We worked in a small team of 3 people.

Bentley / VW Konzern
1 year
2019-11 - 2020-10

Old monolithic architecture was to be replaced by a new microservice architecture

Kotlin Backend Developer
Kotlin Backend Developer
Greenfield project with a development team of 20 people. The old monolithic architecture was to be replaced by a new microservice architecture. Existing business logic had to be transferred to services. Kotlin with Spring Boot was used. Deployment took place on the Azure Cloud with an AKS cluster.

Deutsche Vermögensberatung

Position

Position

Full Stack Developer

Kompetenzen

Kompetenzen

Top-Skills

Fullstack Java Spring Boot Go Kubernetes AWS Azure Docker CI/CD

Produkte / Standards / Erfahrungen / Methoden

Profile

  • My heart has always been in technology, especially software development. I am constantly continuing my education and am now proficient in a wide range of programming languages and software development technologies
  • My main focus is on backend development, but I am also proficient in fullstack. If you ask me about my passion, it is definitely development with the Go programming language. I have already written high performance services with Go, as well as tried out new things with Webassembly


Skills

  • Golang - My favorite programming language
  • Java / Kotlin - Programming language I have worked the most with in projects
  • Cloud Architecture - Deployment and configuration of Kubernetes, communication of microservices, Infra as Code


COMPETENCIES

CLOUD

  • KUBERNETES 
  • CI/CD 
  • JWT / OAUTH 
  • AZURE 
  • AWS 


FRAMEWORKS

  • SPRING BOOT
  • KTOR
  • REACT
  • Selenium
  • Compose Multiplatform


BUILD TOOLS

  • MAVEN
  • GRADLE
  • WEBPACK


CONTAINER

  • Docker 
  • Helm Charts


What is important for me in regards of coding

Throughout my projects I learned one thing: code is more often read than written. What implications does this have? For me clean code practices and test driven development are practices which I value the most. But not in an ideological way, but in a way to integrate it smoothly in the development process. 

When you write code which clearly shows it?s intent, which is not over engineered and over abstracted, it is far easier for others to read your code and to test it. So win win!


PROJECT OVERVIEW (LAST 3 PROJECTS)

01/2024 - 12/2024
Role: Technical Lead
Customer: Ignite Applications Inc.

Tasks:
Greenfield project for the startup Ignite Applications Inc. founded by us, building an EdTech platform for students. The backend is designed as a serverless architecture in which functions are executed using the Go programming language

01/2023 - 01/2024
Role: Senior Backend Developer
Customer: yourIT GmbH

Tasks:
Further development of an existing microservice architecture with different technologies. Kotlin, Golang and C#.NET were used. Communication between the services took place asynchronously via Kafka.

01/2022 - 11/2022
Role: Senior Java Backend Developer
Customer: Lufthansa Airplus GmbH

Tasks:

Further development of a complex gateway service for processing credit card transactions. Java was used in the backend with Spring Boot. The challenge was the complexity of the transactions, as well as the fast transaction processing.


MY SIDEPROJECTS

Kotlin Native JVMTI client

Yes you can write dynamic C libraries with Kotlin ! I wrote a JVMTI client with Kotlin Native to analyze JVM runtime behaviour. The challenging part was using the JVM global lock in the right time in the right places to read object metadata without creating some hard to track bugs.


Clojure / GO Windows binary runner on virtual CPU

I wrote a small service which could read the windows binary format and load it into a virtual memory / CPU to run he binary and analyze the behavior. Pretty challenging even understanding how windows binaries are loaded into memory and how does an operating system work.


EMPLOYMENT HISTORY

01/2018 - 06/2019

Role: Java Developer

Customer: Devoteam GmbH


Tasks:

Employed as a Java Developer we were working in a team of 5 for Lufthansa Airplus developing multiple Java Spring Boot microservices handling credit card transactions. The challenging factor was the throughput and handling lots of data with asynchronous communcation. The microservices were all deployed with to Kubernetes and configures with helm templates.


06/2016 - 12/2017

Role: Data Warehouse Developer

Customer: RSM Consult GmbH


Tasks:

Employed as a Data Warehouse Developer building complex ETL pipelines with IBM Cognos. My main task was to directly communicate with our customer, take their requirements and build ETL processes around the needed Reporting. I built the complete pipeline from database to reports which were developed with Javascript.


01/2014 - 05/2016

Role: ABAP OO / Fiori / UI5 Developer

Customer: AdS Consulting GmbH


Tasks:

Employed as a SAP Developer I built forms for S3 with ABAP in the context of the FI module. We also helped companies switching to S4/Hana where I implemented complex UI logic with Fiori / UI5


Programmiersprachen

KOTLIN
JAVA
GOLANG
PYTHON
C#.NET

Datenbanken

MYSQL
REDIS
POSTGRES
MongoDB

Datenkommunikation

REST
SOAP
WEBSOCKETS
GRPC

Einsatzorte

Einsatzorte

Hamburg (+50km)
Deutschland, Schweiz, Österreich
möglich

Projekte

Projekte

1 year
2024-01 - 2024-12

Greenfield project

Technical Lead
Technical Lead
Greenfield project  building an EdTech platform for students. The backend is designed as a serverless architecture in which functions are executed using the Go programming language and communicate with a MongoDB database. The frontend is a classic React application.
on Request
1 year 1 month
2023-01 - 2024-01

Backend Development

Senior Backend Developer
Senior Backend Developer
Further development of an existing microservice architecture with different technologies. Kotlin, Golang and C#.NET were used. Communication between the services took place asynchronously via Kafka. The existing frontend was tested automatically using Selenium to test the entirety of the business logic.

yourIT GmbH
11 months
2022-01 - 2022-11

Development of a complex gateway service

Senior Java Backend Developer
Senior Java Backend Developer
Further development of a complex gateway service for processing credit card transactions. Java was used in the backend with Spring Boot. The challenge was the complexity of the transactions and the fast transaction processing. Deployment took place on the Azure Cloud with an AKS cluster.

Lufthansa Airplus GmbH
7 months
2021-06 - 2021-12

Development of a cloud native PIM (Product Information Management) application

Python Backend Developer
Python Backend Developer
Further development of a cloud native PIM (Product Information Management) application, using Python as the programming language. The PIM was not implemented as a traditional backend, but ran purely as AWS Lambda functions. In addition, my role was to coordinate with product partners (national / international).

Galeria
8 months
2020-11 - 2021-06

Construction of a prototype to extend the test framework at Bentley

Kotlin Developer
Kotlin Developer
Construction of a prototype to extend the test framework at Bentley. This involved developing small test services to simulate business logic. Kotlin and Golang were used. We worked in a small team of 3 people.

Bentley / VW Konzern
1 year
2019-11 - 2020-10

Old monolithic architecture was to be replaced by a new microservice architecture

Kotlin Backend Developer
Kotlin Backend Developer
Greenfield project with a development team of 20 people. The old monolithic architecture was to be replaced by a new microservice architecture. Existing business logic had to be transferred to services. Kotlin with Spring Boot was used. Deployment took place on the Azure Cloud with an AKS cluster.

Deutsche Vermögensberatung

Position

Position

Full Stack Developer

Kompetenzen

Kompetenzen

Top-Skills

Fullstack Java Spring Boot Go Kubernetes AWS Azure Docker CI/CD

Produkte / Standards / Erfahrungen / Methoden

Profile

  • My heart has always been in technology, especially software development. I am constantly continuing my education and am now proficient in a wide range of programming languages and software development technologies
  • My main focus is on backend development, but I am also proficient in fullstack. If you ask me about my passion, it is definitely development with the Go programming language. I have already written high performance services with Go, as well as tried out new things with Webassembly


Skills

  • Golang - My favorite programming language
  • Java / Kotlin - Programming language I have worked the most with in projects
  • Cloud Architecture - Deployment and configuration of Kubernetes, communication of microservices, Infra as Code


COMPETENCIES

CLOUD

  • KUBERNETES 
  • CI/CD 
  • JWT / OAUTH 
  • AZURE 
  • AWS 


FRAMEWORKS

  • SPRING BOOT
  • KTOR
  • REACT
  • Selenium
  • Compose Multiplatform


BUILD TOOLS

  • MAVEN
  • GRADLE
  • WEBPACK


CONTAINER

  • Docker 
  • Helm Charts


What is important for me in regards of coding

Throughout my projects I learned one thing: code is more often read than written. What implications does this have? For me clean code practices and test driven development are practices which I value the most. But not in an ideological way, but in a way to integrate it smoothly in the development process. 

When you write code which clearly shows it?s intent, which is not over engineered and over abstracted, it is far easier for others to read your code and to test it. So win win!


PROJECT OVERVIEW (LAST 3 PROJECTS)

01/2024 - 12/2024
Role: Technical Lead
Customer: Ignite Applications Inc.

Tasks:
Greenfield project for the startup Ignite Applications Inc. founded by us, building an EdTech platform for students. The backend is designed as a serverless architecture in which functions are executed using the Go programming language

01/2023 - 01/2024
Role: Senior Backend Developer
Customer: yourIT GmbH

Tasks:
Further development of an existing microservice architecture with different technologies. Kotlin, Golang and C#.NET were used. Communication between the services took place asynchronously via Kafka.

01/2022 - 11/2022
Role: Senior Java Backend Developer
Customer: Lufthansa Airplus GmbH

Tasks:

Further development of a complex gateway service for processing credit card transactions. Java was used in the backend with Spring Boot. The challenge was the complexity of the transactions, as well as the fast transaction processing.


MY SIDEPROJECTS

Kotlin Native JVMTI client

Yes you can write dynamic C libraries with Kotlin ! I wrote a JVMTI client with Kotlin Native to analyze JVM runtime behaviour. The challenging part was using the JVM global lock in the right time in the right places to read object metadata without creating some hard to track bugs.


Clojure / GO Windows binary runner on virtual CPU

I wrote a small service which could read the windows binary format and load it into a virtual memory / CPU to run he binary and analyze the behavior. Pretty challenging even understanding how windows binaries are loaded into memory and how does an operating system work.


EMPLOYMENT HISTORY

01/2018 - 06/2019

Role: Java Developer

Customer: Devoteam GmbH


Tasks:

Employed as a Java Developer we were working in a team of 5 for Lufthansa Airplus developing multiple Java Spring Boot microservices handling credit card transactions. The challenging factor was the throughput and handling lots of data with asynchronous communcation. The microservices were all deployed with to Kubernetes and configures with helm templates.


06/2016 - 12/2017

Role: Data Warehouse Developer

Customer: RSM Consult GmbH


Tasks:

Employed as a Data Warehouse Developer building complex ETL pipelines with IBM Cognos. My main task was to directly communicate with our customer, take their requirements and build ETL processes around the needed Reporting. I built the complete pipeline from database to reports which were developed with Javascript.


01/2014 - 05/2016

Role: ABAP OO / Fiori / UI5 Developer

Customer: AdS Consulting GmbH


Tasks:

Employed as a SAP Developer I built forms for S3 with ABAP in the context of the FI module. We also helped companies switching to S4/Hana where I implemented complex UI logic with Fiori / UI5


Programmiersprachen

KOTLIN
JAVA
GOLANG
PYTHON
C#.NET

Datenbanken

MYSQL
REDIS
POSTGRES
MongoDB

Datenkommunikation

REST
SOAP
WEBSOCKETS
GRPC

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