Senior Backend Engineer – Rails & Microservices Lead

Zoolatech; Poland; On-site; PLN 167,000 - 335,000; Full time

Job summary

Zoolatech is seeking an experienced backend engineer to join as an independent contractor. You will build and maintain backend services using Ruby on Rails, evolve a microservice architecture, and ensure scalable and reliable systems.

You will collaborate with data scientists and engineers, participate in code reviews, design testing strategies, and ship high-quality features with end-to-end ownership in a fast-paced environment.

Qualifications

• 5+ years of back-end development with Ruby on Rails.
• Experience building API-based applications.
• Understanding of data structures and distributed microservices.
• Experience with relational databases and SQL (MySQL preferred).
• Bachelor's degree in Computer Science or related field.
• English: active intermediate level or higher.

Responsibilities

• Build and maintain backend services.
• Maintain and evolve microservice architecture (Kafka, GraphQL).
• Design and implement tests and testing strategy.
• Support and troubleshoot production systems.
• Participate in code reviews and design discussions.
• Collaborate cross-functionally with data scientists and engineers.

Skills

Ruby on Rails

API development

Distributed microservices

SQL / MySQL

English (intermediate+)

Education

Bachelor's degree in Computer Science or related field

Tools

GraphQL

AWS

RSpec

CI/CD

Job description

Zoolatech is seeking an experienced backend engineer to join as an independent contractor. You will build and maintain backend services using Ruby on Rails, evolve a microservice architecture, and ensure scalable and reliable systems.

You will collaborate with data scientists and engineers, participate in code reviews, design testing strategies, and ship high-quality features with end-to-end ownership in a fast-paced environment.