Senior Java Software Engineer

Doghouse Recruitment; Amsterdam; Hybrid; EUR 80,000 - 100,000; Full time

Benefits offered by this job

30 vacation days

Paid holidays Eve (Christmas Eve / New

Learning budget

Bike leasing (JobRad)

EU remote up to 30 days/year

Weekly team evenings

Small engineering teams

Job summary

Doghouse Recruitment is assisting an established software company in Amsterdam in finding a Java Developer with 5+ years of experience. You will work on a large Java 21 platform built with core Java, Jetty/Netty, and homegrown frameworks, focusing on backend development.

Expect ~70% new feature work and 30% maintenance, with responsibilities including distributed systems, REST APIs, and platform modernization, and strong English communication and ownership culture.

Qualifications

• 5+ years of professional software engineering experience.
• Strong core Java knowledge and understanding of concurrency/multi-threading.
• Experience with complex mature codebases and backend APIs.

Responsibilities

• Develop new features on a large Java 21 platform.
• Maintain and improve existing code and technical debt.
• Collaborate on distributed systems, REST APIs, and platform modernization.

Skills

Core Java

Concurrency

Backend APIs

English

Tools

Kafka

Jetty

Netty

JPA

Job description

My client is an established software company with more than 20 years of experience in data integration, primarily serving the DACH market with a strong focus on the logistics industry.

Their platform connects modern and legacy systems and runs both in the cloud (AWS) and on-premises.

With around 2,000 customers, the company is now modernizing its product and engineering organization, introducing new APIs, AI capabilities, and an improved user experience.

The engineering culture is also evolving toward greater ownership, customer focus, open communication, and product thinking.

About the Role

Are you a Java Developer with at least 5 years of professional experience? You will work on a large and complex Java 21 platform built primarily with core Java, rather than Spring Boot. The environment includes homegrown frameworks alongside technologies such as Jetty, Netty, and JPA.

The role is strongly backend-focused, with approximately 70% new feature development and 30% maintenance and technical debt. Depending on the team, you may work on distributed systems, high availability, REST APIs, user permissions, secure remote data access, observability, and platform modernization.

What You Will Bring

• 5+ years of professional software engineering experience
• Strong core Java knowledge
• Good understanding of concurrency, multithreading, and parallel processing
• Experience working with complex or mature codebases
• Understanding of backend architecture and APIs
• Willingness to work with and improve legacy code
• A customer-focused and product-oriented mindset
• Strong communication skills in English

Nice to Have

• Experience with Kafka, AMQP, MQTT, Jetty, Netty, JPA, Hazelcast, Infinispan, Prometheus, Micrometer, OpenTelemetry/OTLP, AWS, or distributed/high-availability systems would be beneficial but is not required.
• Experience using AI tools to improve engineering productivity or tackle technical debt would also be highly relevant.
• 30 vacation days per year
• Paid days off on Christmas Eve and New Year's Eve
• Personal learning and development budget
• JobRad bike leasing
• Work remotely from another EU country for up to 30 days per year
• Weekly team evenings
• Small engineering teams with meaningful ownership

€80,000–€100,000 gross per year, depending on experience.