Senior Java Backend Developer / Integration Engineer

Hive-X; Town of Belgium (WI); On-site; USD 100,000 - 130,000; Full time

Benefits offered by this job

Collaborative team environment

Opportunity to contribute to sensitive projects

Long-term engagement

Job summary

A healthcare technology company is seeking 5 Senior Java Backend Developers/Integration Engineers in the Town of Belgium, WI. The position involves designing reliable backend services and secure APIs within a modern Java environment. You will develop integrations and ensure the platform's reliability. A hybrid work model is possible, and the role may engage as freelance or employee, depending on the profile. Strong expertise in Java and Spring is required, with a focus on API design and system integration.

Qualifications

• Strong experience in backend development with Java and Spring.
• Solid knowledge of API design, security, and system integration.
• Experience with relational databases such as MariaDB or MySQL.

Responsibilities

• Designing and implementing backend features in a modern Java stack.
• Building and maintaining secure APIs and gateway flows.
• Developing integrations with external systems and healthcare partners.

Skills

Java Backend Development

Spring Framework

API Design

System Integration

Relational Databases

Cloud Environments

Testing

Collaboration

Tools

Spring Boot

MariaDB

Redis

JUnit

AWS SDK

Job description

We are looking for a 5 Senior Java Backend Developers / Integration Engineers to strengthen the team working in pharma sector, a strategic integration platform in the healthcare ecosystem. This role is ideal for someone who enjoys building reliable backend services, secure APIs, event-driven integrations, and cloud-connected data flows in a modern Java environment.

Mission

You will join a team responsible for the evolution of the solution, a multi-module platform built around integration, interoperability, security, and data exchange.

Responsibilities

• Designing and implementing backend features in a modern Java stack
• Building and maintaining secure APIs and gateway flows
• Developing integrations with external systems and healthcare partners
• Working on event-driven communication and asynchronous processing
• Contributing to data persistence, migration, and operational reliability
• Supporting cloud-based data exchange patterns and AWS-connected services
• Ensuring code quality through unit and integration testing
• Collaborating closely with analysts, architects, and product stakeholders

Tech Environment

The current stack includes:

• Spring Boot 4
• Spring Cloud Gateway
• Spring WebFlux
• Spring Security
• Spring Data JPA
• MariaDB
• Flyway
• Redis
• JWT / OAuth2 Resource Server
• AWS SDK with S3 , Glue , Athena
• OpenAPI / Springdoc
• Jackson
• Parquet / Hadoop
• Maven
• JUnit 5 / Mockito

Qualifications

• Strong experience in backend development with Java and Spring
• Solid knowledge of API design, security, and system integration
• Experience with relational databases such as MariaDB or MySQL
• Experience with messaging platforms such as Kafka
• Familiarity with cloud environments, ideally AWS
• Good understanding of authentication and authorization mechanisms such as JWT and OAuth2
• A quality-driven mindset with attention to testing, maintainability, and production reliability
• The ability to work autonomously while collaborating effectively with a broader team

Nice to Have

• Experience with Spring Cloud Gateway or API gateway patterns
• Experience with Redis
• Exposure to healthcare, interoperability, or regulated environments
• Experience with data pipelines or analytical storage flows using S3 / Athena / Glue
• Familiarity with hexagonal architecture or domain-driven design principles

Benefits

• Strategic project with real business and integration impact
• Modern Java and Spring ecosystem
• Combination of backend engineering, integration, security, and cloud topics
• Collaborative team environment
• Opportunity to contribute to a platform used in a sensitive and meaningful domain

Practical Information

• Location: Belgium / hybrid possible
• Engagement: freelance or employee, depending on profile
• Duration: long-term reinforcement for the team