Java Backend Engineer (m/f/x)

osapiens; Mannheim; On-site; EUR 70,000 - 100,000; Full time

Job summary

osapiens invites a Java Backend Engineer to join our Mannheim-based team, working hybrid three days on-site to power the osapiens HUB, a scalable cloud platform for cross-company collaboration, automation, and compliance.

You will design and develop enterprise Java applications, own features end-to-end, shape architecture in a fast-paced Agile setting, and mentor peers to ensure high-quality code across the backend stack.

Qualifications

• Passion for Platform Engineering.
• Proficiency with Java/J2EE, Spring or Spring Boot.
• Relational and NoSQL databases (PostgreSQL, MongoDB, Cassandra).
• RESTful and/or SOAP API development.
• Experience with automated tests (unit, integration, end-to-end).
• Understanding of distributed systems challenges (scalability, consistency, availability).
• Familiarity with Git and agile mindset.

Responsibilities

• Design & Develop: Build and implement Java-based enterprise software with a focus on backend architecture and scalable system design.
• Own Features: Take full ownership of features from concept to delivery and support.
• Shape Architecture: Contribute to architectural decisions and design planning in an agile environment.
• Mentor & Review: Support junior developers and conduct peer code reviews to uphold quality.
• Collaborate & Grow: Work within an agile team and continuously grow technical and professional skills.

Skills

Java

Spring/Spring Boot

REST API development

SOAP API development

Distributed systems

Git

Agile practices

Code reviews

Tools

Git

Job description

Java Backend Engineer (m/f/x)

Department: osapiens Hub

Employment Type: Permanent - Full Time

Location: Mannheim

Description

About osapiens

At osapiens, more than 550 talented minds unite around one mission: enabling sustainable growth for businesses worldwide. Founded in 2018 and headquartered in Mannheim, Germany, we have built the AI-driven osapiens HUB - a multi-tenant platform hosting 26 enterprise-grade solutions designed for cross-company collaboration, automation, and compliance. With offices across Europe and the US, we are shaping the future of scalable and secure business technology.

Your Team

Our Backend Engineers (Hybrid in Mannheim · 3 days/week on-site) build the foundation of the osapiens HUB - the cloud platform powering all our SaaS products. The team develops engines for seamless monitoring, real-time data processing, centralized integration, automated workflows, and dynamic app development. Simply put: they build the core technologies that enable global companies to turn compliance into efficiency and sustainable growth.

Your Key Responsibilities

• Design & Develop: Build and implement Java-based enterprise software with a strong focus on backend architecture and scalable system design.
• Own Features: Take full ownership of features from concept to delivery and ongoing support.
• Shape Architecture: Contribute to architectural decisions, technical discussions, and design planning in an agile environment.
• Mentor & Review: Support junior developers and conduct peer code reviews to uphold high-quality coding standards.
• Collaborate & Grow: Work closely within an agile development team, learning from senior engineers and continuously growing your technical and professional skill set.

Your Experience

• Passion for Platform Engineering: You’re excited about building scalable, distributed backend systems that create real-world impact for global companies.
• Java Expertise: Solid experience with Java or JavaEE, ideally with Spring or Spring Boot frameworks.
• Database Skills: Proficiency with relational and/or NoSQL databases such as PostgreSQL, MongoDB, or Cassandra.
• API Development: Strong experience building and integrating RESTful and/or SOAP web services.
• Test Automation: Experience implementing and maintaining automated tests (unit, integration, end-to-end).
• Distributed Systems Knowledge: Understanding of common challenges such as scalability, consistency, and availability.
• Modern Engineering Practices: Familiarity with Git and a collaborative, agile mindset.
• Bonus Skills: Hands-on experience with search and analytics engines like OpenSearch or Elasticsearch is a plus.

Join us for this and more...

• A purpose-driven mission tackling complex sustainability challenges while working alongside global industry pioneers at a fast-growing unicorn company
• Room for creativity through collaborative teamwork and an open communication culture
• Flexibility and team bonding with our hybrid work options
• Fuel for your growth journey, both personally and professionally
• Sustainable mobility options, promoting eco-friendly commuting solutions
• Fun team events and outings with our global teams
• Inspiring workspaces in Mannheim and beyond