Senior Software Engineer

Doghouse Recruitment

Germany

1 day ago

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Role details

Contract type

Permanent contract

Employment type

Full-time (> 32 hours)

Experience level

Expert

Experience required

5 years minimum

Working hours

Regular working hours

Job source

www.adzuna.de

Tech stack

Java (Programming Language) Artificial Intelligence Business Systems Code Review Data Integration Software Debugging Distributed Systems Java Persistence API Junit PostgreSQL Microsoft SQL Server MongoDB

+14 more

MySQL Oracle (Applications) Software Tools Mockito Jetty Multithreading Load Balancing Concurrency Spring-boot Technical Debt Backend Code Restructuring Automation Anywhere Microservices

Job description

Senior Software Engineer - Core Java - Java 21 monolith - Remote within Germany

Our client is a data integration platform serving more than 2,000 customers, helping them connect business systems, automate workflows, and exchange data across cloud and on-premise environments. Their platform powers supply chains through real-time integration, automation, and intelligent data processing.

The codebase is a Java 21 monolith with no microservices and no Spring Boot but rather homegrown framework built on top of libraries such as Netty, Jetty, and JPA. This role sits in a team, where the focus is not distributed systems or load balancing but using AI to modernize and clean up legacy tech debt + improve internal AI workflows within the codebase.

What You’ll Do

Design, develop, test, and maintain production-grade backend software in Java
Work through legacy code to identify and resolve tech debt, using AI-assisted engineering tools as a core part of the workflow
Contribute to technical design discussions and code reviews
Debug and optimize complex production systems
Collaborate closely with Product, QA, and fellow engineers to deliver high-quality releases
Take ownership of features from implementation through production

Requirements

5+ years of backend Java development
Strong Core Java skills, including the ability to write Java without the Spring Boot framework
Genuine, hands-on experience using AI tools to refactor, clean up, or modernize legacy codebases (not just AI-assisted feature work)
Experience with concurrency and multithreading
Experience with JUnit, Mockito, or similar testing frameworks
Experience with PostgreSQL, Oracle, MySQL, SQL Server, or MongoDB
Comfortable working in a large, mature monolithic codebase, with curiosity about legacy decisions rather than a desire to rewrite from scratch