Senior Fullstack Engineer – React and Kotlin Specialists

About the Position

Senior Fullstack Engineer – React and Kotlin Specialists

Warszawa, Poland (Remote)

Salary: 18 480 - 21 840 PLN (B2B)

Unleash innovation - design the future of intelligent advertising ecosystems!

Warszawa-based opportunity with hybrid work model.

As a Senior Fullstack Engineer – React and Kotlin Specialists, you will be working for our client, a leader in building advanced advertising tools, focusing on creating intelligent recommendation systems and automating campaign management for advertisers on Allegro Ads. Join a mission-driven project that revolutionizes how businesses grow through cutting-edge technology and data-driven insights, offering exciting avenues for professional growth and innovation.

Responsibilities

• Develop and maintain backend services using Kotlin, integrating machine learning-driven recommendation engines in collaboration with data science teams.
• Build scalable, event-driven architectures to process large data volumes within cloud environments, leveraging GCP.
• Design and implement high-performance APIs to support analytical dashboards and market benchmarks.
• Create and optimize scalable microfrontends using React, prioritizing accessibility and server-side rendering for analytical tools.
• Collaborate with cross-functional teams to deliver seamless, secure, and efficient software solutions.
• Ensure high code quality through testing frameworks such as Jest, Vitest, or Playwright, with a focus on performance and reliability.
• Contribute to evolving microservice architectures, utilizing Spring Boot, MongoDB, SQL, and cloud-native tools.
• Participate actively in code reviews, sprint planning, and technical discussions to foster continuous improvement.

Requirements

• At least 3 years of experience in full-stack development, with a focus on React and Kotlin.
• Strong proficiency in TypeScript, React, HTML/CSS, and backend technologies like Kotlin, Spring Boot, and microservices.
• Experience working with cloud ecosystems, preferably GCP.
• Solid understanding of database management, including MongoDB and SQL.
• Familiarity with event-driven architectures and large-scale data processing.
• Ability to communicate effectively in Polish and English.
• Experience working in an Agile environment with a focus on delivering high-quality software.

Nice to Have

• Certifications related to GCP or microservices architecture.
• Experience with agentic coding tools like Copilot/OpenCode.
• Knowledge of accessibility standards (a11y) and performance optimization techniques.

We Offer

• Competitive salary
• Opportunity to work in a mission-driven project
• Access to ITDS Clubs, medical insurance, Multisport, Pluralsight, and more
• Integrational Events and Ambassador Program

About the Company

Join our team and contribute to the future of intelligent advertising ecosystems. We are committed to fostering a collaborative and innovative environment where your skills and ideas can thrive.

Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

Internal number #9046