Salary range: B2B 37-46E/h + VAT Ciklum  is looking for a  Senior Ruby on Rails Developer  to join our team full-time in Poland. We are a custom product engineering company that supports both multinational organizations and scaling startups to solve their most complex business challenges. With a global team of over 4,000 highly skilled developers, consultants, analysts and product owners, we engineer technology that redefines industries and shapes the way people live. About the role: As a Senior Ruby on Rails Developer, become a part of a cross-functional development team engineering experiences of tomorrow. Together, we will work on the project that aims to power loyalty programs for some of the largest global Retail, QSR, Airline, Grocery, and Gasoline merchants. The platform handles nearly half a billion API calls a day – with a global footprint in four AWS regions.  Responsibilities: Back-end development to meet customer’s business needs and implement components according to modern software development environments (cloud-based platforms, microservice architecture, etc.) Taking part in the decision-making process of application architecture design, solution development, architecture, and code review Develop and review feature design documents and provide inputs/updates to the solution specification Design and implement a set of various types of tests (unit, integration, functional, etc) Proactive position in solution development, and process improvements Working in an international distributed team in an Agile environment Communicate with PMs, engineers, Architects, QA and other colleagues and stakeholders Delivering the product roadmap and plannings Following coding standards, software best practices and writing highly testable, automatable and performant code over the whole SDLC. Requirements: Excellent knowledge in Computer Science, Computing Theory: Paradigm & Principles (OOP, SOLID, TDD, BDD) Database theory (RDBMS) Code testing practices Enterprise and Design Patterns Microservices architecture, SOA Security patterns, Common attacks types (OWASP) Understanding of network interactions: Protocols Conventions (GraphQL, REST) Excellent knowledge of Ruby programming language, paradigms, constructs, and idioms (more than 5 years) Excellent knowledge and experience in Ruby on Rails (more than 5 years) Practical commercial experience with: RDBMS (e.g, PostgreSQL) Key-value storages (Redis) Version control systems (GIT) Cloud computing platforms (AWS, GCP, Azure) Microservices Docker Continuous Integration tools (e.g. Gitlab Pipeline, Jenkins) Experience with Troubleshooting, profiling, and debugging applications Creation software architecture and design of complex applications, platforms Agile software processes and technologies Code Review process Refactoring process Fluent or Upper-Intermediate English You can: Perform a broad range of complex technical or professional activities, in a variety of contexts. Investigate, define, and resolve complex issues Able to work in distributed cross-functional teams effectively Influence customers and team members on the project level May supervise others or make decisions which impact the work assigned to individuals or phases of projects Plan, schedule, and monitor your own work (and of others where applicable) competently Have learning agility (readiness for challenge and being open to change) Desirable : Experience in software development for more than 6 years Understanding of orchestration and containerization (e.g. Kubernetes, Docker Swarm) Knowledge in Deployment patterns Experience with TDD environments (RSpec, Minitest, Capybara, Selenium) Experience with web architecture at scale (20krpm and above) Experience solving logistical problems with software Autoscaling, monitoring, and alerting approaches What's in it for you? Care: your mental and physical health is our priority. We ensure comprehensive company-paid medical insurance, life insurance and Multisport card Tailored education path: boost your skills and knowledge with our regular internal events (meetups, conferences, workshops), Udemy license, language courses and company-paid certifications Growth environment: share your experience and level up your expertise with a community of skilled professionals, locally and globally Flexibility: Own your schedule – you are the one to decide when to start your working day. Just don’t miss your regular team stand-up Opportunities: we value our specialists and always find the best options for them. Our Internal Mobility Program helps change a project if needed to help you grow, excel professionally and fulfill your potential Global impact: work on large-scale projects that redefine industries with international and fast-growing clients Welcoming environment: feel empowered with a friendly team, open-door policy, informal atmosphere within the company and regular team-building events About us: Join a well-established company and a strong team of professionals.  Seize the perks of global opportunities, local approach and start-up spirit.  Boost your skills with modern stacks and industry-leading clients! Enjoy what you do, do what you enjoy!  Be bold, not bored! Interested already? We would love to get to know you! Submit your application. Can’t wait to see you at Ciklum.