Ruby Principal Engineer: Architect & Lead, Rails Expert

Sigma Software; Warszawa; On-site; PLN 250,000 - 350,000; Full time

Job summary

Sigma Software in Warszawa seeks a Principal Software Engineer with deep Ruby expertise to lead the technical direction of our platform and drive scalable systems. You will architect high-performance solutions, mentor engineers, and collaborate across teams to deliver robust features while maintaining code quality and engineering excellence.

The role demands hands-on coding balanced with strategic thinking, cloud familiarity, and a passion for cutting-edge technologies to keep us ahead in a

Qualifications

• 8–10+ years of software development experience with leadership.
• Expert-level Ruby and Rails expertise.
• Bachelor's degree in CS/SE or equivalent.
• Proficient in PostgreSQL/MySQL and Git.
• Strong knowledge of software design patterns and testing.
• Experience with TDD and automated testing frameworks.
• Experience with Agile methodologies and distributed systems.
• Ability to mentor junior developers and lead teams.

Responsibilities

• Architect and implement scalable, high‑performance Ruby/Rails solutions.
• Lead the design and development of new features and products with strong coding standards.
• Collaborate with cross‑functional teams to define technical strategies.
• Mentor and guide junior developers, conduct code reviews and provide feedback.
• Optimize existing systems for performance and scalability; evolve tech stack.
• Participate in technical decision‑making and future engineering direction.
• Stay up‑to‑date with emerging technologies and industry trends.

Skills

Ruby

Ruby on Rails

Leadership

TDD

Cloud platforms

Databases

Git

Agile methodologies

Education

Bachelor's degree in Computer Science, Software Engineering, or related field

Tools

Git

PostgreSQL

MySQL

AWS

Job description

Sigma Software in Warszawa seeks a Principal Software Engineer with deep Ruby expertise to lead the technical direction of our platform and drive scalable systems. You will architect high-performance solutions, mentor engineers, and collaborate across teams to deliver robust features while maintaining code quality and engineering excellence.

The role demands hands-on coding balanced with strategic thinking, cloud familiarity, and a passion for cutting-edge technologies to keep us ahead in a