Senior Backend Engineer - Scalable Java in Warsaw

Moss; Warsaw (IN); On-site; USD 47,482 - 68,585; Full time

Benefits offered by this job

Equity

Office culture & events

Work from abroad (20 days)

Learning & Development budget

Local benefits

Job summary

Moss is seeking Senior Backend Engineers (f/m/d) for multiple Warsaw teams: Sales Enablement, Pricing & Billing, Acquisition, Spend Management, and Activation & Card Spend. You will collaborate with designers, PMs and frontend engineers to build scalable backend services, APIs, and testing strategies.

You should have proven backend leadership, Java/Spring experience, and strong REST API design with a focus on performance, reliability, and end-to-end testing. English fluency is required.

Qualifications

• Proven Backend Engineer experience leading end-to-end projects.
• Proficiency in Java with Spring; microservices, queues, monitoring and feature flags.
• Strong REST API design and testing practices.
• Fluent in English.

Responsibilities

• Backend development leading the application aligned with product requirements.
• Collaborate with PMs and designers during project kick-offs to refine backend and UI/UX concepts.
• Collaborate with frontend engineers to define APIs and frontend functionality.
• Write well-tested code and perform unit and integration tests.
• Plan efficient rollout strategies and monitor performance based on user feedback.

Skills

Java

Spring framework

Microservices

Message queue

Alerting

Reliability

Feature flags

REST API design

Testing (unit/integration)

English

Job description

Moss is seeking Senior Backend Engineers (f/m/d) for multiple Warsaw teams: Sales Enablement, Pricing & Billing, Acquisition, Spend Management, and Activation & Card Spend. You will collaborate with designers, PMs and frontend engineers to build scalable backend services, APIs, and testing strategies.

You should have proven backend leadership, Java/Spring experience, and strong REST API design with a focus on performance, reliability, and end-to-end testing. English fluency is required.