Senior Java Backend Engineer - Networking & Data Platform

Doghouse Recruitment; Deutschland; Hybrid; USD 85,324 - 108,077; Full time

Benefits offered by this job

Personal learning budget

Remote work flexibility

Up to 30 days remote work per year

Job summary

Doghouse Recruitment is seeking a Senior Software Engineer – Java with a networking focus to extend our data platform and integration systems. You will work in backend engineering on network-layer components, data transport, and scalable infrastructure, collaborating with senior engineers and leveraging AI to enhance productivity.

You will design and implement Java networking solutions, enable robust load balancing, and integrate cloud with on-prem sources while participating in code reviews and

Qualifications

• 3–6 years of backend development experience with strong Java skills.
• Solid understanding of Java networking internals (NIO, sockets, HTTP tunnelling).
• Practical experience with Netty or similar async frameworks (Vert.x, gRPC).
• Knowledge of load balancing concepts (L4/L7, health checks, failover).
• Debugging low-level networking or concurrency issues.

Responsibilities

• Develop, test, and deploy core backend components of the data platform.
• Design network-layer solutions in Java (HTTP tunnelling, TCP/IP).
• Build and maintain load balancing strategies for high-availability systems.
• Design integrations of cloud systems with on-prem sources.
• Contribute to technical designs and code reviews.
• Integrate AI tools to accelerate development and automation.
• Collaborate with QA and product teams on reliable releases.

Skills

Java backend

Networking internals

Netty

Concurrency

Test automation

HTTP/REST/WebSocket

AI augmentation

English communication

Tools

Netty

Vert.x

gRPC

JUnit

Mockito

PostgreSQL

MongoDB

Job description

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

About the Role

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. The team uses homegrown frameworks built on top of libraries such as Netty, Jetty, and JPA.

What You'll Do

• Design, develop, test, and maintain production-grade backend software in Java
• Build reliable, scalable, and maintainable platform capabilities
• 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
• Use AI-assisted engineering tools to improve productivity, automate repetitive work, and enhance software quality
• Take ownership of features from implementation through production

What We're Looking For

• 5+ years of backend Java development
• Strong Core Java skills, including the ability to write Java without the Spring Boot framework
• 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 monolithic codebase

Bonus Skills: Experience in one or more of the following is highly valued and maps to specific teams

• Platform Engineering High availability, load balancing, connection pooling, failover, performance optimization