Senior Backend Engineer (Java/Kotlin) — High-Scale

Allegro; Toruń; Hybrid; PLN 210,000 - 3,469,000; Full time

Benefits offered by this job

Annual bonus

RSUs (Allegro shares)

MacBook Pro or Dell laptop

Cafeteria benefits (medical, sports, v

English classes paid by company

Training budget and hackathons

Volunteer day

Job summary

Allegro's Razor team maintains the critical backend for checkout and purchase, handling massive scale with high availability. You’ll own microservices in a cloud-native stack (Java, Kotlin, Spring, MongoDB) and collaborate across PMs and engineering teams.

The role supports hybrid work with flexible hours (4/1) and up to 30 days of remote work, based in Toruń. Enjoy annual bonus, RSUs, and a comprehensive benefits cafeteria plus tech gear.

Qualifications

• 5 years of experience building and maintaining complex, high-scalability systems.
• Proficiency in Java (primary) and Kotlin, with a focus on reactive programming.
• Hands-on experience with MongoDB and cloud-native environments.
• Ability to collaborate with Product Managers and cross-functional teams.
• Willingness to participate in on-call rotations to ensure system reliability.

Responsibilities

• Design, build, and optimize systems that handle thousands of requests per second.
• Work in a cloud-native environment (GCP) using Java, Kotlin, Spring, and MongoDB.
• Take ownership of microservices from design to deployment in an agile team.
• Partner with PMs to analyze requirements and drive initiatives across Allegro.
• Contribute to innovation with Large Language Models and AI tools.
• Mentor teammates and maintain high availability through on-call duties.

Skills

Java

Kotlin

Reactive programming

Team collaboration

On-call rotation

Tools

MongoDB

Kubernetes

Docker

Consul

GitHub

GitHub Actions

Job description

Allegro's Razor team maintains the critical backend for checkout and purchase, handling massive scale with high availability. You’ll own microservices in a cloud-native stack (Java, Kotlin, Spring, MongoDB) and collaborate across PMs and engineering teams.

The role supports hybrid work with flexible hours (4/1) and up to 30 days of remote work, based in Toruń. Enjoy annual bonus, RSUs, and a comprehensive benefits cafeteria plus tech gear.