Senior Backend Architect (Java)

On behalf of our Client from the US, Mobilunity is looking for a Senior Backend Architect (Java).
 

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 are not looking for someone who simply implements requirements.
 

We are looking for an engineer with a strong consultant mindset who:

• understands business goals before proposing technical solutions;
• is comfortable working with ambiguous requirements;
• asks the right questions instead of waiting for detailed specifications;
• evaluates architectural trade-offs between scalability, performance, operational complexity, and cost;
• independently designs scalable solutions;
• communicates technical decisions clearly to both engineering and business stakeholders;
• takes ownership of technical decisions and their business impact;
• leverages AI tools to improve engineering productivity while applying independent technical judgment.
   

Requirements:

• 8+ years of professional Java development experience.
• Strong expertise in Java SE and Spring Framework (Core, MVC, Spring Boot).
• Solid experience designing scalable backend systems and distributed architectures.
• Strong understanding of software architecture principles and design patterns.
• Experience with microservices and event-driven architecture.
• Experience with Kafka or similar messaging technologies.
• Strong SQL skills and experience with relational databases.
• Experience working with AWS or other cloud platforms.
• Strong analytical and problem-solving skills.
• Ability to evaluate scalability, performance, reliability and cost trade-offs.
• Experience participating in architectural discussions and technical decision-making.
• Experience communicating directly with business stakeholders.
• Excellent written and spoken English.
   

Responsibilities:

• Design scalable backend architecture for business-critical systems.
• Translate business requirements into technical solutions.
• Evaluate architectural alternatives and justify technical decisions.
• Improve platform scalability, performance and operational efficiency.
• Design integrations with internal systems and third-party services.
• Participate in technical strategy and long-term architecture planning.
• Collaborate directly with the CTO, Tech Lead and business stakeholders.
• Mentor engineers and contribute to engineering best practices.
• Promote AI-assisted engineering workflows across the development process.
• Take ownership of complex technical domains from design through delivery.
   

Nice to have:

• SAP Commerce (Hybris).
• Marketplace or e-commerce experience.
• High-load distributed systems.
• Automotive, retail or e-commerce background.
• Startup experience.
• Experience working directly with CTOs, founders or product leadership.
• Previous experience as a Tech Lead or Software Architect.
• Experience with AI-assisted software development (Cursor, Claude Code, ChatGPT, etc.).
   

In return we offer:

• The friendliest community of like-minded IT-people
• Open knowledge-sharing environment – exclusive access to a rich pool of colleagues willing to share their endless insights into the broadest variety of modern technologies
• Mobilunity Medical Insurance program designed to attend our teams’ needs
• Paid vacations and sick leaves, including 5 paid days per year that don’t require a sick note
• Perfect office location in the city-center (900m from Lukyanivska metro station with a green and spacious neighborhood) or remote mode engagement: you can choose a convenient one for you, with a possibility to fit together both
• No open-spaces setup – separate rooms for every team’s comfort and multiple lounge and gaming zones
• English classes in 1-to-1 & group modes with elements of gamification
• Neverending fun: sports events, tournaments, music band, multiple affinity groups
   

Come on board, and let’s grow together!