Senior Java Developer (system design) (вакансія неактивна)

On behalf of our Client from the US, Mobilunity is looking for a Senior Java Developer.

You will work on mission-critical backend systems powering a large-scale US e-commerce platform. The role involves designing and developing backend services, integrations, inventory synchronization, order processing, pricing logic, and marketplace integrations supporting a high-traffic online business.

This is not a typical feature-delivery role. You’ll participate in architectural discussions, solve complex engineering problems, and collaborate directly with technical and business stakeholders to deliver scalable solutions.

Candidates must be available to work primarily during US business hours, with a preferred schedule of 1:00 PM — 8:00 PM CET.

What we’re looking for:

We’re looking for more than a Senior Java Developer.

We need an engineer who enjoys understanding business problems before proposing technical solutions.

You should be comfortable working with open-ended challenges, evaluating trade-offs, asking the right questions, and independently designing scalable backend solutions.

The ideal candidate:

• thinks beyond implementation;
• understands business impact;
• enjoys solving complex engineering problems;
• proactively identifies bottlenecks;
• can justify architectural decisions;
• understands scalability, performance and cost optimization;
• uses AI as an engineering productivity tool while applying independent judgment.

Responsibilities:

• Design, develop and maintain scalable backend services using Java and Spring.
• Build integrations with internal services, marketplaces and external partners.
• Develop REST and SOAP APIs.
• Work on inventory synchronization, pricing, catalog management and order processing.
• Participate in architecture discussions and technical decision-making.
• Troubleshoot production issues.
• Collaborate directly with engineering and business stakeholders.
• Improve system scalability, reliability and performance.
• Contribute to engineering standards and development best practices.

Requirements:

• 7+ years of commercial Java experience.
• Strong Java SE and OOP knowledge.
• Spring Boot, Spring Framework.
• Hibernate/JPA.
• REST APIs.
• SOAP.
• SQL (MySQL or similar).
• Software architecture principles.
• Experience designing scalable backend systems.
• Strong analytical and problem-solving skills.
• Advanced English.

Nice to have:

• SAP Commerce (Hybris)
• AWS
• Docker
• Kafka
• CI/CD
• GraphQL
• Marketplace integrations
• Event-driven architecture
• High-load systems
• Automotive / Retail / E-commerce
• AI-assisted development
• Experience working with US companies