Senior Ruby on Rails Developer

About usLLInformatics is a forward-thinking IT consulting firm, trusted by clients across Europe and North America. We specialize in delivering complex projects on time, with exceptional quality, and always meeting the highest compliance standards. Our remote-first team of 130+ experts is passionate about building cutting-edge digital products that drive real results. With a focus on data-driven decisions, measurable outcomes, and a strategic mindset, we’re raising the bar in our industry—backed by a strong, collaborative work culture that fuels our success.Contract Type: B2BLocation: Remote or in our Warsaw officeYour Tasks and Responsibilities:Implementing new functionalities on our client’s platform.Solving complex programming challenges while improving your knowledge.Conducting regular code reviews / PR reviews for your colleagues.Maintaining existing code and fixing bugs.Writing unit, integration, and E2E tests.Contributing to frontend components using React when needed.Supporting rapid iteration, experimentation, and data-driven development initiatives.Optimizing application performance, reliability, and scalability.Collaborating with Product Managers and cross-functional teams to align engineering execution with product vision.Requirements:6+ years of experience in Ruby on Rails.Familiarity with Active Record and RSpec.Experience working on production applications in AWS or Heroku.Experience working with RDBMS like PostgreSQL.Experience writing tests / following a TDD approach or strong testing culture.Experience building server-side applications using the MVC pattern or similar.React experience (building components, integrating APIs).Understanding distributed systems and resilient applications.Practical knowledge of REST API communication.Polish and English at B2+ minimum level.Familiarity with Agile methodologies (Scrum, Kanban).Experience as a tech team lead is a strong plus.Demonstrated ability to leverage AI tools to improve workflows or development efficiency is a plus.Why join us? Flexible Working Hours – We focus on results! Manage your time, keep your team informed about your availability, and attend key meetings.Work from Anywhere – Choose your ideal setup! Work 100% remotely within the EU, go hybrid, or enjoy our Warsaw office, fully equipped for productivity.Comprehensive Onboarding – From day one, we ensure you feel comfortable and supported, so you can quickly become part of the team.Flat Structure – We value initiative and open communication. Every voice matters here!Positive Company Culture & Team Spirit – We create an environment where everyone feels appreciated and comfortable.Modern Work Methods – We use cutting-edge project management techniques inspired by the IT world.Transparent Communication – Regular 360° feedback sessions and mentor support to help you grow.Top-Notch Equipment – Get a MacBook for your work. If you choose to work from our Warsaw office, you'll also have access to a 34” (16:9) widescreen monitor and an ergonomic standing desk.Weekly English Lessons – Optional classes with a native speaker to help you improve your skills.