Senior Full-Stack Ruby Engineer 

We are looking for an experienced Full-Stack Engineer to join the EU-based Client’s Technical Team for the development of a new portal and extend our existing backend platform. The portal will allow small and mid-sized businesses to book staffing services fully online, enabling the company’s transition from semi-manual operations to a scalable B2B self-service platform. 

In this role, you will primarily focus on backend development in Ruby on Rails, building APIs, extending production systems, and helping scale the platform architecture. You will collaborate with frontend and mobile developers to ensure smooth integrations and a reliable customer experience. 

This is a great opportunity for engineers who enjoy working with real production systems, improving architecture, and building scalable backend services that power customer-facing products. 

Experience / Skills required: 

Must have: 

• Strong backend development experience with Ruby on Rails 
• Experience designing and building REST APIs and backend integrations 
• Solid knowledge of PostgreSQL, including data modeling and performance optimization 
• Experience working with scalable system architectures 
• Ability to work with and extend existing production systems 
• Experience with Git / GitHub workflows 
• Familiarity with AWS-based infrastructure 
• Upper-Intermediate English and better 

Good to have: 

• Experience with React, React Native  
• Knowledge of TypeScript / JavaScript  
• Experience building or integrating microservices  
• Experience with Rust or C++ for performance-critical processing 

Responsibilities: 

• Design, develop, and extend backend services using Ruby on Rails 
• Build and maintain scalable APIs supporting the new customer portal and mobile integrations 
• Improve and optimize PostgreSQL data models and database performance 
• Contribute to the evolution of a microservices-based architecture 
• Collaborate with frontend and mobile developers to support React Native integrations 
• Work with existing production systems, ensuring reliability, maintainability, and scalability 
• Support the development of performance-critical services where applicable 

We offer:  

• Competitive salary with the regular review 
• Medical Insurance after 3 months probation period (can be used in Ukraine) 
• Vacation (up to 20 working days) 
• Sick leaves (10 working days) 
• National Holidays as a time off (11 days) 
• Online English courses 
• Accountant assistance and legal support 
• Flexible working schedule, remote, office-based or hybrid format  
• Fully-equipped perfect office space located in the city center (ready for work in blackouts) 
• Direct cooperation with the customer 
• Dynamic environment with low level of bureaucracy and great team spirit 
• Challenging projects in diverse business domains and a variety of tech stacks 
• Communication with Top/Senior level specialists to strengthen your hard skills 
• Online/offline teambuildings 
• Volunteering culture development and support