Senior Ruby on Rails Developer

Momentum; Wrocław; On-site; PLN 180,000 - 260,000; Full time

Job summary

Momentum is hiring a Senior Ruby on Rails Developer to build robust, scalable web apps for HealthTech clients worldwide. You will write and review code, influence architecture, optimize performance, and ensure secure, maintainable delivery.

You will work closely with PMs, designers and other engineers, leveraging AI daily to accelerate work while maintaining high quality. A strong focus on testing (RSpec), CI/CD, PostgreSQL and REST/WebSocket interfaces, plus a passion for quality, security and

Qualifications

• 5+ years of commercial experience with Ruby on Rails.
• Strong knowledge of relational database design (PostgreSQL).
• Ability to implement various ways of communication with the client (REST API, WebSockets).
• Experience with CI/CD, deployment tools, Docker and Git.
• Practical knowledge of design patterns and SOLID principles.

Responsibilities

• Designing and building web applications using Ruby on Rails.
• Designing and implementing relational databases.
• Collaborating with cross-functional teams to define, design and ship new features.
• Writing automated tests for your code, including edge cases and reliability.
• Fixing bugs and improving performance.
• Reviewing code, including AI-generated code, to standards.
• Helping define internal standards for maintainability and style.
• Using AI tools to speed up development work.
• Communicating directly with clients when needed.

Skills

Ruby on Rails

English fluency

Polish language

Client communication

Code reviews

Education

Bachelor's degree in Computer Science or related field

Tools

PostgreSQL

Docker

Git

REST API

WebSockets

CI/CD

Nginx

AWS

Job description

At Momentum, we accelerate digital innovation in healthcare. Our mission is to empower HealthTech startups and scaleups by transforming ideas into cutting-edge digital products. We combine deep industry expertise, strategic consulting, and full-stack development to create solutions that drive growth, compliance, and patient impact.

We work AI-first. AI is part of our everyday work, in development and in delivery. We keep testing new tools, agents and workflows, and when we find a better way to build, we change how we work.

But in healthcare, AI output is a starting point, not a final answer. Verification and ownership stay with us. We believe in technology that makes healthcare more accessible, efficient, and human-centered.

Role overview:

We are looking for a Senior Ruby on Rails Developer to help build robust, scalable web applications for clients around the world, mainly in HealthTech but not only.

You'll write and review code, contribute to architecture decisions, optimize performance and care about code quality, working closely with PMs, designers and other developers. You'll use AI every day to move faster, and you'll be the one who makes sure the code is actually correct, secure and maintainable before it gets merged. "AI generated it" isn't done. In healthcare, a subtle bug or a missed edge case costs more than time.

Requirements:

• 5+ years of commercial experience with Ruby and Ruby on Rails,
• Strong knowledge of relational database design (e.g. PostgreSQL),
• Ability to implement various ways of communication with the client (e.g. REST API, WebSockets),
• Experience with CI/CD, deployment tools, Docker and Git,
• Practical knowledge of design patterns and SOLID principles,
• Practical experience in writing and maintaining automated tests using RSpec or similar frameworks,
• Practical knowledge of non-relational databases, caching and message brokers,
• Experience in diagnosing and solving performance and optimization problems,
• Ability to contribute to project architecture based on business, functional and non-functional requirements, with an understanding of scalability concepts,
• Love for code review, both giving and receiving it,
• Willingness to help other developers and share knowledge,
• Using AI tools in your daily work and the ability to critically review AI-generated code before it reaches the codebase,
• Fluent written and spoken English, and confidence in talking directly with clients, e.g. during calls, demos or technical discussions
• Fluent written and spoken Polish, as it's our main language of internal communication,
• Interest in HealthTech and readiness to work on projects where quality, security and compliance really matter.

Nice to have:

• Experience with AWS or similar platform
• Experience with Web Server (e.g. Nginx)
• Degree in Computer Science or relevant field
• Healthtech or pharmacy experience: HIPAA, e-prescribing, insurance, FHIR.
• You've worked embedded with a client, in consulting, as an FDE or in a startup where you wore several hats.

Responsibilities:

• Designing and building web applications using Ruby on Rails,
• Designing and implementing relational databases,
• Collaborating with cross-functional teams to define, design and ship new features,
• Writing automated tests for your code, including edge cases, usability and general reliability,
• Fixing bugs and improving performance,
• Reviewing code, including AI-generated code, with the same standards as any other,
• Helping define and improve internal standards for maintainability and style,
• Using AI tools (e.g. Claude) to speed up development work,
• Communicating directly with clients when needed: clarifying requirements