Backend Software Engineer (Java & Kotlin)

Quick Facts

• Role: Backend engineer for e-commerce platform APIs and services
• Focus: Kotlin/Java, Spring Boot, microservices, MongoDB, GCP

Description

Design, develop, and maintain scalable backend services and APIs for an e-commerce platform transforming from a general marketplace into specialized “stores within a store”. You will build microservices-based solutions with reliability, performance, and maintainability in mind, and continuously improve existing systems. The work includes using AI-assisted and agentic coding tools during development.

Responsibilities

• Design, develop, and maintain backend services and APIs using Kotlin, Java, and Spring Boot
• Build and evolve solutions based on microservices architecture
• Design architecture for new modules and contribute to key technical decisions
• Optimize and improve existing systems (performance, scalability, code quality)
• Work with MongoDB, Spring Data MongoDB, and Google Cloud Platform (GCP)
• Write and maintain well-tested, high-quality code following engineering best practices
• Use AI-assisted and agentic coding tools as part of daily development workflow
• Collaborate with Product Managers, Data Analysts, UX Designers, and other engineers to translate product and business needs into technical solutions
• Occasionally contribute beyond the backend (web or mobile) as needed

Requirements

• Ability to effectively use AI-assisted development tools (e.g., GitHub Copilot, OpenCode, or other agentic coding tools) daily
• Strong proficiency in Kotlin and Java
• Hands-on experience with Spring Boot backend development
• Experience designing and implementing microservices-based solutions
• Strong focus on building, testing, and maintaining high-quality backend services and APIs
• Ability to design architecture for new modules and proactively identify optimization opportunities
• Experience working with product and business teams to define and refine technical and functional requirements
• Strong understanding of software engineering best practices and commitment to high engineering standards
• English proficiency at B2+ level or higher

Benefits

• B2B contract compensation: 20–26k PLN
• Access to the Worksmile platform
• Growth- and innovation-oriented work environment