Senior Ruby on Rails Developer - Freelance - Wrocław/Remote

Monterail; Wrocław; Hybrid; PLN 180,000 - 250,000; Full time

Job summary

Monterail is seeking a Senior Ruby on Rails Developer to join a client in the luxury travel and hospitality space. The role focuses on migrating data and business logic from a legacy MS SQL Server system, developing back-office features in Rails, and building integrations with CRM and payment gateways.

The position is based in Wrocław, Poland, with 90% remote work and occasional office visits; Wrocław is a strategic focus for the company.

Qualifications

• Solid commercial experience with Ruby on Rails.
• Skills in relational database design (normalization, data integrity).
• Basic React familiarity.
• Awareness of working in a CI/CD and containerized environment infrastructure.
• Understanding of secure application design principles.

Responsibilities

• Developing back-office features in Rails.
• Modeling and designing the PostgreSQL database with a strong focus on security and normalization (premium customer data).
• Migrating data and business logic from the legacy system (MS SQL Server) — analyzing existing structures and porting them thoughtfully and securely.
• Building integrations with external systems (CRM, payment gateway).
• Working with PM/PO to reconstruct domain logic from the old system.
• Maintaining code quality and security in the context of sensitive customer and billing data.

Skills

Ruby on Rails

Relational database design

React basics

CI/CD & containerized environments

Secure application design

Tools

PostgreSQL

MS SQL Server

Job description

Hi,

Hi! We are Monterail. A team of ~130 developers, designers, QAs and other technology professionals building innovative software everyday. We work with clients around the globe. We've helped businesses of all sizes develop outstanding digital products.

We are currently looking for a Senior Ruby on Rails Developer to join one of our clients - a company operating in the luxury travel & hospitality space, managing an exclusive collection of premium properties across the Mediterranean.

Project Description

Our client's engineering team builds and maintains the internal tools that power the client-matching, sales, and operations workflows behind their business. The stack is Ruby on Rails + PostgreSQL (hosted on AWS) alongside Next.js, with a trunk-based repo, CI/CD, and multiple deploys per day. This role is focused on a migration project.

Role is based in Wrocław, Poland. 90% remote work with occasional office visits but Wrocław is important from a stategic perspective.

Key Responsibilities

What you’ll be doing

• Developing back-office features in Rails
• Modeling and designing the PostgreSQL database with a strong focus on security and normalization (premium customer data)
• Migrating data and business logic from the legacy system (MS SQL Server) — analyzing existing structures and porting them thoughtfully and securely
• Building integrations with external systems (CRM, payment gateway)
• Working with PM/PO to reconstruct domain logic from the old system
• Maintaining code quality and security in the context of sensitive customer and billing data

What we’re looking for

• Solid commercial experience with Ruby on Rails
• Skills in relational database design (normalization, data integrity)
• Basic React familiarity
• Awareness of working in a CI/CD and containerized environment infrastructure
• Understanding of secure application design principles

Nice to have

• Experience with data/system migrations, Pundit, Inertia.js, feature flags
• Knowledge of C#/.NET
• Experience in the travel/hospitality industry or in projects with a strong customer-care focus