Senior Full-Stack Engineer: Java/React & Cloud Platform

BlackLine Systems, Inc.; Kraków; On-site; PLN 254,000 - 318,000; Full time

Job summary

BlackLine Systems, Inc. is seeking a Senior Full-Stack Engineer for the UI Platform team in Kraków.

You will build and maintain the core App Shell and the supporting micro-frontend services, bridging Java backends with React frontends and guiding modern, cloud-native deployments. With 4-8 years of experience, you’ll own SDLC from specs to delivery, collaborate in an agile setting, and mentor junior engineers while advancing platform-wide best practices.

Qualifications

• 4-8 years of professional full-stack software development experience.
• Strong expertise in Java and React with TypeScript.
• Solid experience with major cloud platforms (AWS, Azure, or GCP) and cloud-native services.
• Experience managing the SDLC from requirements to delivery.
• Hands-on CI/CD experience and DevOps mindset (Jenkins, GitHub Actions).
• Ability to work independently and collaborate in an agile environment.

Responsibilities

• Develop and maintain the core App Shell and services powering the micro-frontend ecosystem.
• Bridge backend Java and frontend React roles for seamless inter-app communication.
• Define integration strategies and enable cloud capabilities for faster, secure shipping.
• Write clean, secure, testable code and implement unit, integration tests across backend and frontend.
• Mentor junior engineers and contribute to team knowledge on full stack best practices.

Skills

Java (OOP)

React with TypeScript

Cloud platforms

SDLC ownership

DevOps

Independent worker

Tools

Jenkins

GitHub Actions

Terraform

Job description

BlackLine Systems, Inc. is seeking a Senior Full-Stack Engineer for the UI Platform team in Kraków.

You will build and maintain the core App Shell and the supporting micro-frontend services, bridging Java backends with React frontends and guiding modern, cloud-native deployments. With 4-8 years of experience, you’ll own SDLC from specs to delivery, collaborate in an agile setting, and mentor junior engineers while advancing platform-wide best practices.