Senior Software Developer with 6+ years in back-end, full-stack & cloud-native systems. Skilled in modernising legacy apps, Python, Java, Kotlin, SQL
Aktualisiert am 04.09.2025
Profil
Freiberufler / Selbstständiger
Remote-Arbeit
Verfügbar ab: 01.10.2025
Verfügbar zu: 100%
davon vor Ort: 100%
Python
Java
SQL
Kotlin
TypeScript
C#
NoSQL
REST
REST API
Spring Boot
Hibernate
JPA
React
Angular
AWS
GitLab
Docker
Kubernetes
JUnit
Mockito
Android
Linux
CI/CD
Romanian
Muttersprache
English
Fluent
Russian
Fluent
French
Intermediate
German
Beginner

Einsatzorte

Einsatzorte

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

Projekte

Projekte

1 year 9 months
2025-01 - now

Software Development

Senior Software Developer API CI/CD DevOps ...
Senior Software Developer
  • Modernised a 30-year-old platform, ensuring regulatory compliance, by Reverse Engineering existing, historically evolved structures.
  • Stack & infrastructure upgrade: Java 1.8/Python 3.8 ? Java 21/Python 3.12; Ubuntu 20?24, PostgreSQL 12?17.
  • Cut API latency 5?8s ? <700 ms (Java?Python refactor 2s ? <1s).
  • Secured REST API (Python, Docker, Redis, SQL) with robust session management
  • Introduction of comprehensive testing (Unit, Integration, and Usability in Java/ Kotlin/ Python/ TypeScript), which increased defect detection by approximately 35%.
  • Team Lead & QA Manager mentoring on secure, TDD practices by introducing and implementing modern DevOps concepts: automation, build and deployment pipelines (CI/CD)
API CI/CD DevOps Docker Java Kotlin PostgreSQL Python Redis REST API Reverse Engineering SQL session management TypeScript Ubuntu automation infrastructure mentoring QA regulatory compliance testing Usability
Lion Software GmbH
Hamburg (Germany)
7 months
2024-01 - 2024-07

Machine Learning Engineering

Machine Learning Engineer data pipelines Machine Learning Python ...
Machine Learning Engineer
  • Designed RL experiments in an open-ended multi-stage game; compared multi-stage vs. hardest-difficulty training strategies. Built Python data pipelines for children?s play session capture ? training human-like behavioural models.
  • MLFlow analysis for 200+ runs (params, performance, predictions) ? lightweight experimental architecture enabling fast comparison of approaches.
data pipelines Machine Learning Python architecture experiments predictions
PlayYoli
Copenhagen (Denmark)
10 months
2023-03 - 2023-12

Software Development

Software Developer/ Data Analyst AWS S3 AWS JSON ...
Software Developer/ Data Analyst
  • Migrated analytics pipeline: AWS S3, conversion of JSON ? Parquet using Lambda + Glue
  • Integrated AWS QuickSight dashboards, Dockerized Python Lambdas, tested with Pytest
  • Enhanced Kotlin prototype, including AWS Cognito integration
AWS S3 AWS JSON Kotlin Parquet Pytest Python prototype dashboards
PlayYoli
Copenhagen (Denmark)
1 year 2 months
2022-01 - 2023-02

Full-Stack Development

Full-Stack Developer/ Data Scientist (.NET, C#) .NET Core .NET C# ...
Full-Stack Developer/ Data Scientist (.NET, C#)
  • Migrated legacy app .aspx ? Razor Pages (.NET Core) with REST microservices + SQL Server.
  • Delivered REST APIs and reporting tools for researchers. Integrated workflows for reproducible, cloud-based reporting and data access.
.NET Core .NET C# data access microservices SQL Server REST APIs reporting tools reproducible researchers workflows
ICES (International Council for the Exploration of the Sea)
Copenhagen (Denmark)
1 year 5 months
2020-08 - 2021-12

Developed an IoT healthcare solution

Kotlin and Android Developer backend Firebase Kotlin ...
Kotlin and Android Developer
  • Developed an IoT healthcare solution (Android + Firebase NoSQL, Kotlin backend Coroutines)
  • Approved by Danish Medical Association (DADL) ? one of Denmark?s first IoT COPD monitors
backend Firebase Kotlin NoSQL IoT
StepUp Solutions (Air)
Copenhagen (Denmark)
1 year 7 months
2017-03 - 2018-09

Development

Java Back-End Developer CI/CD Integration tests Java ...
Java Back-End Developer
  • Built REST APIs (Java, Spring Boot, PostgreSQL), integrated with Jenkins CI/CD pipelines
  • Unit & Integration tests (JUnit, Mockito) for safe inter-service interactions
CI/CD Integration tests Java Java Back-End Jenkins JUnit Mockito PostgreSQL REST APIs Spring Boot
Endava
Bucharest (Romania)

Aus- und Weiterbildung

Aus- und Weiterbildung

2 years 2 months
2021-09 - 2023-10

Study - Computer Games & Programming

Master of Science, IT University of Copenhagen
Master of Science
IT University of Copenhagen
2 years 10 months
2018-09 - 2021-06

Study - Information Technology (New Media & Communication)

Bachelor of Science, Aalborg University
Bachelor of Science
Aalborg University

Position

Position

Senior Software Developer with 6+ years of experience in enterprise modernisation, REST API development, and cloud-native systems. Proven expertise in migrating legacy stacks, optimising performance (APIs cut from 8s ? <700ms), and leading teams through secure, test-driven development. Skilled in Kotlin, Java, Python, C#, SQL/NoSQL, and AWS/Docker/Kubernetes, with hands-on experience in reinforcement learning (MLFlow), CI/CD pipelines, and microservices architecture. Passionate about building scalable systems, cloud data pipelines, and developer-friendly processes. Open to remote, hybrid, or on-site opportunities.

Kompetenzen

Kompetenzen

Top-Skills

Python Java SQL Kotlin TypeScript C# NoSQL REST REST API Spring Boot Hibernate JPA React Angular AWS GitLab Docker Kubernetes JUnit Mockito Android Linux CI/CD

Produkte / Standards / Erfahrungen / Methoden

CAREER SUMMARY
Senior Software Developer with 6+ years of experience in back-end, full-stack, and cloud-native systems. Specialised in modernising legacy enterprise apps, building REST APIs and introducing DevOps/QA practices. Skilled in Java, Kotlin, Python, C#, SQL/NoSQL, AWS, Docker, Redis, CI/CD pipelines, with additional experience in AI/ML and front-end frameworks (React, Angular).

SKILLS

  • Frameworks: REST API, Spring Boot, Hibernate/JPA, .NET Core, React, Angular
  • Cloud/DevOps: AWS (Lambda, Glue, S3, Cognito, QuickSight), Docker, Kubernetes, Redis
  • Testing/QA: JUnit, Mockito, Pytest, Postman, Moto, Instrumentation & Usability Testing
  • CI/CD & Process: Jenkins, GitLab CI, CircleCI, Git workflow design
  • Other: Team Leader, QA leadership. Other tools: MLFlow, RMI interoperability tools

Programmiersprachen

Java
Kotlin
Python
SQL
NoSQL
C#
TypeScript

Datenbanken

PostgreSQL
MySQL
SQL Server
MongoDB
DynamoDB
CouchBase

Einsatzorte

Einsatzorte

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

Projekte

Projekte

1 year 9 months
2025-01 - now

Software Development

Senior Software Developer API CI/CD DevOps ...
Senior Software Developer
  • Modernised a 30-year-old platform, ensuring regulatory compliance, by Reverse Engineering existing, historically evolved structures.
  • Stack & infrastructure upgrade: Java 1.8/Python 3.8 ? Java 21/Python 3.12; Ubuntu 20?24, PostgreSQL 12?17.
  • Cut API latency 5?8s ? <700 ms (Java?Python refactor 2s ? <1s).
  • Secured REST API (Python, Docker, Redis, SQL) with robust session management
  • Introduction of comprehensive testing (Unit, Integration, and Usability in Java/ Kotlin/ Python/ TypeScript), which increased defect detection by approximately 35%.
  • Team Lead & QA Manager mentoring on secure, TDD practices by introducing and implementing modern DevOps concepts: automation, build and deployment pipelines (CI/CD)
API CI/CD DevOps Docker Java Kotlin PostgreSQL Python Redis REST API Reverse Engineering SQL session management TypeScript Ubuntu automation infrastructure mentoring QA regulatory compliance testing Usability
Lion Software GmbH
Hamburg (Germany)
7 months
2024-01 - 2024-07

Machine Learning Engineering

Machine Learning Engineer data pipelines Machine Learning Python ...
Machine Learning Engineer
  • Designed RL experiments in an open-ended multi-stage game; compared multi-stage vs. hardest-difficulty training strategies. Built Python data pipelines for children?s play session capture ? training human-like behavioural models.
  • MLFlow analysis for 200+ runs (params, performance, predictions) ? lightweight experimental architecture enabling fast comparison of approaches.
data pipelines Machine Learning Python architecture experiments predictions
PlayYoli
Copenhagen (Denmark)
10 months
2023-03 - 2023-12

Software Development

Software Developer/ Data Analyst AWS S3 AWS JSON ...
Software Developer/ Data Analyst
  • Migrated analytics pipeline: AWS S3, conversion of JSON ? Parquet using Lambda + Glue
  • Integrated AWS QuickSight dashboards, Dockerized Python Lambdas, tested with Pytest
  • Enhanced Kotlin prototype, including AWS Cognito integration
AWS S3 AWS JSON Kotlin Parquet Pytest Python prototype dashboards
PlayYoli
Copenhagen (Denmark)
1 year 2 months
2022-01 - 2023-02

Full-Stack Development

Full-Stack Developer/ Data Scientist (.NET, C#) .NET Core .NET C# ...
Full-Stack Developer/ Data Scientist (.NET, C#)
  • Migrated legacy app .aspx ? Razor Pages (.NET Core) with REST microservices + SQL Server.
  • Delivered REST APIs and reporting tools for researchers. Integrated workflows for reproducible, cloud-based reporting and data access.
.NET Core .NET C# data access microservices SQL Server REST APIs reporting tools reproducible researchers workflows
ICES (International Council for the Exploration of the Sea)
Copenhagen (Denmark)
1 year 5 months
2020-08 - 2021-12

Developed an IoT healthcare solution

Kotlin and Android Developer backend Firebase Kotlin ...
Kotlin and Android Developer
  • Developed an IoT healthcare solution (Android + Firebase NoSQL, Kotlin backend Coroutines)
  • Approved by Danish Medical Association (DADL) ? one of Denmark?s first IoT COPD monitors
backend Firebase Kotlin NoSQL IoT
StepUp Solutions (Air)
Copenhagen (Denmark)
1 year 7 months
2017-03 - 2018-09

Development

Java Back-End Developer CI/CD Integration tests Java ...
Java Back-End Developer
  • Built REST APIs (Java, Spring Boot, PostgreSQL), integrated with Jenkins CI/CD pipelines
  • Unit & Integration tests (JUnit, Mockito) for safe inter-service interactions
CI/CD Integration tests Java Java Back-End Jenkins JUnit Mockito PostgreSQL REST APIs Spring Boot
Endava
Bucharest (Romania)

Aus- und Weiterbildung

Aus- und Weiterbildung

2 years 2 months
2021-09 - 2023-10

Study - Computer Games & Programming

Master of Science, IT University of Copenhagen
Master of Science
IT University of Copenhagen
2 years 10 months
2018-09 - 2021-06

Study - Information Technology (New Media & Communication)

Bachelor of Science, Aalborg University
Bachelor of Science
Aalborg University

Position

Position

Senior Software Developer with 6+ years of experience in enterprise modernisation, REST API development, and cloud-native systems. Proven expertise in migrating legacy stacks, optimising performance (APIs cut from 8s ? <700ms), and leading teams through secure, test-driven development. Skilled in Kotlin, Java, Python, C#, SQL/NoSQL, and AWS/Docker/Kubernetes, with hands-on experience in reinforcement learning (MLFlow), CI/CD pipelines, and microservices architecture. Passionate about building scalable systems, cloud data pipelines, and developer-friendly processes. Open to remote, hybrid, or on-site opportunities.

Kompetenzen

Kompetenzen

Top-Skills

Python Java SQL Kotlin TypeScript C# NoSQL REST REST API Spring Boot Hibernate JPA React Angular AWS GitLab Docker Kubernetes JUnit Mockito Android Linux CI/CD

Produkte / Standards / Erfahrungen / Methoden

CAREER SUMMARY
Senior Software Developer with 6+ years of experience in back-end, full-stack, and cloud-native systems. Specialised in modernising legacy enterprise apps, building REST APIs and introducing DevOps/QA practices. Skilled in Java, Kotlin, Python, C#, SQL/NoSQL, AWS, Docker, Redis, CI/CD pipelines, with additional experience in AI/ML and front-end frameworks (React, Angular).

SKILLS

  • Frameworks: REST API, Spring Boot, Hibernate/JPA, .NET Core, React, Angular
  • Cloud/DevOps: AWS (Lambda, Glue, S3, Cognito, QuickSight), Docker, Kubernetes, Redis
  • Testing/QA: JUnit, Mockito, Pytest, Postman, Moto, Instrumentation & Usability Testing
  • CI/CD & Process: Jenkins, GitLab CI, CircleCI, Git workflow design
  • Other: Team Leader, QA leadership. Other tools: MLFlow, RMI interoperability tools

Programmiersprachen

Java
Kotlin
Python
SQL
NoSQL
C#
TypeScript

Datenbanken

PostgreSQL
MySQL
SQL Server
MongoDB
DynamoDB
CouchBase

Vertrauen Sie auf Randstad

Im Bereich Freelancing
Im Bereich Arbeitnehmerüberlassung / Personalvermittlung

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Rufen Sie uns an +49 89 500316-300 oder schreiben Sie uns:

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