Ruby on Rails Developer (mid/senior)

🏢 Summary: Senior Ruby on Rails Developer responsible for building and maintaining production-grade server-side applications, implementing new features, and ensuring high code quality through testing and reviews. The role involves working with AWS-based environments, optimizing performance and scalability, and contributing to frontend components in React. The position requires close collaboration with cross-functional teams in a remote or hybrid setup. 🗂️ Requirements: 6+ years of experience with Ruby on Rails, Experience with Active Record and RSpec, Experience with AWS or Heroku in production environments, Experience with PostgreSQL or other RDBMS, Experience writing unit, integration, and E2E tests, Experience with TDD or strong testing practices, Experience building applications using MVC pattern, Experience building React components and integrating APIs, Understanding of distributed systems, Experience designing and consuming REST APIs, Knowledge of Agile methodologies (Scrum or Kanban), Polish and English at minimum B2 level 📃 Skills: Ruby, Rails, ActiveRecord, RSpec, AWS, Heroku, PostgreSQL, RDBMS, React, REST, MVC, TDD, Scrum, Kanban 🏢 Description: About us LLInformatics 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: B2B Location: Remote or in our Warsaw office Your 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.

🏢 Summary: B2B contract for a Ruby on Rails Developer to build and maintain a client platform, implement new features, and ensure performance and reliability in a remote or hybrid setup. The role involves backend development with Rails, testing, database management, and occasional frontend support with React. You will collaborate in an Agile team to deliver high-quality, production-ready solutions. 🗂️ Requirements: 3+ years experience with Ruby on Rails, Knowledge of Active Record, Knowledge of RSpec, Experience with production applications, Familiarity with relational databases, Experience writing unit and integration tests, Understanding of MVC architecture, Basic experience with React, Understanding of REST API principles, English B2 level minimum, Polish B2 level minimum, Familiarity with Agile methodologies 📃 Skills: Ruby, Rails, ActiveRecord, RSpec, PostgreSQL, React, REST, AWS, Heroku, Scrum, Kanban, MVC 🏢 Description: About us LLInformatics 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: B2B Location: Remote or in our Warsaw office Your Tasks and Responsibilities: Implementing new features on our client’s platform. Solving programming challenges and continuously developing your skills. Participating in code reviews and collaborating with team members. Maintaining the existing codebase and fixing bugs. Writing unit and integration tests (E2E is a plus). Supporting frontend development using React when needed. Contributing to product improvements through experimentation and iteration. Taking care of application performance and reliability. Collaborating with Product Managers and team members to deliver high-quality solutions. Requirements: 3+ years of experience with Ruby on Rails. Good knowledge of Active Record and RSpec. Experience working with production applications (AWS or Heroku is a plus). Familiarity with relational databases (e.g., PostgreSQL). Experience writing tests and understanding of testing best practices. Understanding of the MVC pattern or similar architectures. Basic experience with React (components, API integration). Understanding of REST API principles. English and Polish at a minimum B2 level. Familiarity with Agile methodologies (Scrum, Kanban). Nice to have: Experience with distributed systems. Interest in using AI tools to improve development workflow. 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.

🏢 Summary: B2B contract for a senior backend-focused engineer to design and develop scalable APIs and services using Ruby on Rails, with supporting frontend work in React. The role involves building production-grade systems, ensuring high test coverage, and improving performance, reliability, and scalability in a distributed environment. 🗂️ Requirements: 6+ years commercial experience with Ruby on Rails, Experience building production APIs and backend systems, Entry-level experience with React (components, state management, API integration), Knowledge of PostgreSQL and relational databases, Experience with RSpec and automated testing, Experience with AWS and/or Heroku, Understanding of scalable and distributed systems, Experience working in Agile teams, English and Polish at minimum B2+ 📃 Skills: Ruby, Rails, React, PostgreSQL, SQL, RSpec, AWS, Heroku, API, REST, JavaScript, Git 🏢 Description: About us LLInformatics 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: B2B Location: Remote or in our Warsaw office Your Tasks and Responsibilities: Design and develop backend features and APIs using Ruby on Rails as the primary technology stack. Contribute to frontend development in React, including building components and integrating APIs when needed. Build scalable backend services and APIs powering applications. Develop reusable frontend components and maintain a clean UI architecture. Collaborate directly with Product, Design, QA, and DevOps teams to deliver business-focused solutions. Improve application performance, reliability, scalability, and maintainability. Write clean, production-grade code with strong test coverage (unit, integration, E2E). Review code, maintain engineering standards, and support technical decision-making. Troubleshoot production issues and support stable deployments. Participate in agile delivery processes and contribute to continuous improvement. Support knowledge sharing and technical mentorship within the team. Requirements: 6+ years of commercial Ruby on Rails experience. Solid entry-level React experience (components, state management, API integration). Strong experience building production APIs and backend systems. Good knowledge of PostgreSQL and relational databases. Experience with RSpec, automated testing, and strong engineering practices. Experience with AWS and/or Heroku. Understanding of scalable and distributed systems. Experience working in Agile teams. Strong communication skills in English at a minimum B2+ level. Nice to Have: Tech Lead or mentoring experience. Experience with observability, monitoring, and performance optimization. Experience working directly with international stakeholders. 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.

🏢 Summary: Senior Ruby on Rails engineer role focused on designing and building scalable, production-grade backend systems and APIs in a remote-first environment. The position involves architectural decision-making, performance optimization, mentoring, and close collaboration with cross-functional teams. The offer includes flexible remote work within the EU, modern equipment, and a strong engineering culture emphasizing quality and automation. 🗂️ Requirements: 6+ years commercial experience with Ruby on Rails, Strong experience building production-grade APIs and backend systems, Advanced knowledge of PostgreSQL, Experience with database optimization and data modeling, Strong experience with RSpec and automated testing, Experience with AWS and/or Heroku, Understanding of distributed systems and system architecture, Experience working in Agile environments, English proficiency at B2+ level 📃 Skills: Ruby, Rails, PostgreSQL, RSpec, AWS, Heroku, APIs, SQL, Git, Agile 🏢 Description: About us LLInformatics 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: B2B Location: Remote or in our Warsaw office Your Tasks and Responsibilities: Design, develop, and own complex backend features and APIs using Ruby on Rails. Architect scalable, reliable, and maintainable backend services. Collaborate closely with Product, QA, DevOps, and business stakeholders to translate requirements into technical solutions. Drive improvements in system performance, scalability, reliability, and engineering quality. Write clean, production-grade code with strong automated test coverage. Review code, establish engineering standards, and contribute to architectural decisions. Troubleshoot complex production issues and support stable, efficient deployments. Participate in agile delivery processes and drive continuous improvement initiatives. Mentor other engineers and actively contribute to knowledge sharing within the team. Requirements: 6+ years of commercial Ruby on Rails experience. Strong experience designing and building production-grade APIs and backend systems. Advanced knowledge of PostgreSQL, database optimization, and data modeling. Strong experience with RSpec, automated testing, and engineering best practices. Experience with AWS and/or Heroku. Good understanding of distributed systems, scalability, and system architecture. Experience working in Agile environments. Strong communication skills in English (B2+). Nice to Have: Technical leadership or mentoring experience. Experience with observability, monitoring, and performance optimization. Experience participating in architectural discussions and technical decision-making. Experience working directly with international stakeholders. 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.

🏢 Summary: B2B contract opportunity for an experienced Ruby on Rails Backend Developer to design, build, and maintain scalable backend services and production-grade APIs in a remote-first environment. The role focuses on delivering high-quality, reliable, and performant solutions in close collaboration with cross-functional teams. Candidates will work in an agile setup, contributing to architecture decisions, automated testing, and continuous improvement initiatives. 🗂️ Requirements: 4+ years of commercial experience with Ruby on Rails, Experience building and maintaining production-grade APIs and backend systems, Knowledge of PostgreSQL and relational database design, Experience with RSpec and automated testing, Experience with AWS and/or Heroku, Understanding of software architecture principles and backend scalability, Experience working in Agile environments, English proficiency at B2+ level 📃 Skills: Ruby, Rails, PostgreSQL, RSpec, AWS, Heroku, Sidekiq, SQL, REST, Git 🏢 Description: About us LLInformatics 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: B2B Location: Remote or in our Warsaw office Your Tasks and Responsibilities: Design, develop, and maintain backend features and APIs using Ruby on Rails. Build scalable backend services supporting business applications. Collaborate with Product, QA, and DevOps teams to deliver business-focused solutions. Improve application performance, reliability, maintainability, and scalability. Write clean, production-ready code with appropriate test coverage (unit and integration tests). Participate in code reviews and follow engineering best practices. Troubleshoot application issues and support production deployments. Participate in agile development processes and contribute to continuous improvement initiatives. Requirements: 4+ years of commercial Ruby on Rails experience. Strong experience building and maintaining production-grade APIs and backend systems. Good knowledge of PostgreSQL and relational database design. Experience with RSpec and automated testing. Experience with AWS and/or Heroku. Understanding of software architecture principles and backend scalability concepts. Experience working in Agile environments. Strong communication skills in English (B2+). Nice to Have: Experience with background processing solutions (e.g., Sidekiq). Experience with monitoring, observability, and performance optimization. Experience working with international teams and stakeholders. 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.

🏢 Summary: B2B IT Project Manager role responsible for end-to-end delivery of multiple software projects, ensuring timelines, budgets, and quality standards are met. The position focuses on operational ownership, KPI-driven performance tracking, and client-facing coordination in Agile and hybrid environments. Fully remote or Warsaw-based with strong emphasis on process optimization and delivery excellence. 🗂️ Requirements: Minimum 4 years experience as IT Project Manager or similar delivery role, Experience managing multiple software projects simultaneously, Experience in software delivery environments, Knowledge of Agile, Lean, and traditional project management methodologies, Experience with budget and resource management, KPI-driven performance monitoring experience, Fluent English (C1 minimum) 📃 Skills: Agile, Lean, ProjectManagement, RiskManagement, Budgeting, ResourcePlanning, KPI, SoftwareDelivery 🏢 Description: About us LLInformatics 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: B2B Location: Remote/Warsaw Your Tasks & Responsibilities Project Delivery & Operational Ownership Plan, execute, and deliver projects on time, within budget, and according to quality standards Define project scope, objectives, deliverables, timelines, and resource allocation Coordinate day-to-day project operations across teams Track project progress, priorities, blockers, and risks Proactively resolve issues and escalate concerns early Ensure accountability and operational efficiency across all project stakeholders Continuously optimize project workflows, tools, and methodologies Client Relationship Management Serve as the main operational point of contact for clients Build strong client trust through responsiveness and transparent communication Provide regular updates on project progress, risks, and milestones Ensure clients consistently feel supported and well-informed Identify opportunities for delivery improvements and enhanced client satisfaction Budget, Resource & Staffing Management Monitor budgets, project costs, and resource efficiency Optimize resource planning and task distribution across teams Define staffing and hiring needs for assigned projects/accounts Coordinate recruitment processes with technical interviewers Ensure strong alignment between client needs and team capabilities Quickly address underperformance or mismatches within project teams Team Operational Management Support team efficiency, collaboration, and overall project health Provide operational feedback to team members Help resolve team performance or collaboration challenges Foster alignment with company culture, values, and delivery expectations Performance Tracking & Continuous Improvement Monitor KPIs related to project delivery, client satisfaction, and operational effectiveness Prepare reports, analyses, and risk assessments Use data-driven insights to implement process improvements Contribute to refining internal project management standards and best practices Requirements Minimum 4 years of experience as an IT Project Manager or similar delivery role Strong ownership mentality and accountability Proven success managing multiple projects simultaneously Excellent organizational and planning capabilities Proactive communication and stakeholder management Strong problem-solving and decision-making skills Ability to work independently while managing multiple priorities Experience in software delivery environments Knowledge of Agile, Lean, and traditional project management methodologies Analytical mindset with KPI-driven decision-making Strong cultural alignment and team leadership capabilities Fluent English (minimum C1) Why Join LLInformatics? Flexible working hours focused on outcomes Work from anywhere in the EU, hybrid, or from our Warsaw office Comprehensive onboarding and mentor support Flat organizational structure with real influence on company processes High-trust, positive team culture Modern project management practices Transparent communication and regular feedback Premium equipment package (MacBook + office workstation setup) Optional weekly English lessons with native speakers Recruitment Process Stage 1: 30-minute video interview with the Recruitment Team Stage 2: 1-hour video interview with the Management Team

🏢 Summary: A junior developer academy program offering hands-on experience with Ruby on Rails under mentorship, leading to potential full-time collaboration. Participants will build features, fix bugs, and write tests while deepening their understanding of web application development. The program starts on-site in Warsaw with the possibility of remote work later. 🗂️ Requirements: Basic knowledge of Ruby on Rails, Basic knowledge of JavaScript, Understanding of web application architecture, Ability to write unit, integration, and end-to-end tests, Upper-Intermediate English (B2+) 📃 Skills: Ruby, Rails, JavaScript, UnitTesting, IntegrationTesting, E2ETesting 🏢 Description: 🚀 LLI Academy 3rd Edition: Now Recruiting! We’re excited to launch the third edition of our LLI Academy – an initiative dedicated to discovering talented junior developers who are passionate about the IT world, coding, and eager to grow their skills in a professional environment. This program is designed to give promising developers the opportunity to gain hands-on experience, receive mentorship, and become a part of our dynamic team. Our previous editions were a great success, resulting in continued cooperation with amazing junior developers who joined our company full-time. Now, we’re looking for the next wave of talent to join us! About us LLInformatics 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 100+ 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. 📍 Location: Warsaw (on-site for first 3 months), then possibility of remote work📄 Contract Type: UZ Your tasks and responsibilities: Develop your coding skills with the support of mentors and a structured curriculum Implement new features and functionalities Solve programming challenges while deepening your understanding of Ruby Participate in regular code reviews and receive feedback from experienced developers Maintain and improve existing codebases (bug fixing, refactoring) Write unit, integration, and end-to-end tests Requirements: Basic knowledge of Ruby on Rails Basic knowledge of JavaScript Eagerness to learn, improve, and tackle new challenges Logical and critical thinking skills Understanding of how web applications work A proactive, hands-on attitude towards solving problems Upper-Intermediate English ( B2+ ) Why join us? Flexible Working Hours – We focus on results! Manage your time, keep your team informed about your availability, and attend key meetings. 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.

🏢 Summary: Hybrid Software Engineer role focused on developing and maintaining a scalable Ruby on Rails platform, building APIs, and delivering secure, high-performance solutions. The position involves implementing new features, supporting integrations with external partners, and contributing to agile development processes. The engineer will also take ownership of services and support ongoing platform reliability. 🗂️ Requirements: Minimum 3 years of professional experience as a Software Engineer, Proficiency in Ruby on Rails, Experience developing and managing APIs, Familiarity with React, Knowledge of JavaScript or TypeScript, Ability to work in a hybrid environment (Warsaw-based), Advanced written and spoken English 📃 Skills: Ruby, Rails, API, React, JavaScript, TypeScript, GraphQL 🏢 Description: Our Client, an American software company is opening a new branch in Warsaw and we are looking for a Software Engineer with Ruby to join a growing team. About the Position This role focuses on enhancing and maintaining a robust platform, supporting new project initiatives, and delivering scalable solutions that improve the user experience for both industry professionals and individual clients. The ideal candidate is proactive, collaborative, and committed to delivering high-quality, scalable software. This is a hybrid role based in Warsaw, Poland. Key Responsibilities Design and implement new functionalities for a cutting-edge platform Develop and manage APIs to enable smooth integration with financial and sales partners Build secure and scalable services designed for sustained performance Support agile development practices and help ensure consistent, impactful sprint results Mentor team members and contribute to a positive engineering culture through knowledge-sharing Maintain and take responsibility for services you develop, including participating in the on-call rotation Requirements Minimum 3 years of professional experience as a Software Engineer good proficiency with Ruby on Rails Excellent communication skills and experience working in cross-functional teams Familiarity with React and component-based front-end frameworks Knowledge of JavaScript and/or TypeScript Ability to perform in a hybrid (office/remote) work environment Advanced written and spoken English (please provide your CV in English) Nice to have Experience with GraphQL

🏢 Summary: Senior Software Engineer role focused on developing and scaling a robust platform using Ruby on Rails, with responsibility for building secure services and APIs. The position involves implementing new features, improving system performance, and supporting integrations with external partners. This hybrid role in Warsaw includes technical ownership of developed services and participation in agile processes. 🗂️ Requirements: Minimum 5 years of professional Software Engineering experience, Strong proficiency in Ruby on Rails, Experience with React and component-based frameworks, Working knowledge of JavaScript or TypeScript, Experience developing and managing APIs, Ability to work in a hybrid (office/remote) model, Advanced written and spoken English 📃 Skills: Ruby, Rails, React, JavaScript, TypeScript, GraphQL, APIs, Agile 🏢 Description: Our Client, an American software company is opening a new branch in Warsaw and we are looking for a Senior Software Engineer with Ruby to join a growing team. About the Position This role focuses on enhancing and maintaining a robust platform, supporting new project initiatives, and delivering scalable solutions that improve the user experience for both industry professionals and individual clients. The ideal candidate is proactive, collaborative, and committed to delivering high-quality, scalable software. This is a hybrid role based in Warsaw, Poland. Key Responsibilities Design and implement new functionalities for a cutting-edge platform Develop and manage APIs to enable smooth integration with financial and sales partners Build secure and scalable services designed for sustained performance Support agile development practices and help ensure consistent, impactful sprint results Mentor team members and contribute to a positive engineering culture through knowledge-sharing Maintain and take responsibility for services you develop, including participating in the on-call rotation Requirements Minimum 5 years of professional experience as a Software Engineer Strong proficiency with Ruby on Rails Excellent communication skills and experience working in cross-functional teams Familiarity with React and component-based front-end frameworks Working knowledge of JavaScript and/or TypeScript Ability to perform in a hybrid (office/remote) work environment Advanced written and spoken English (please provide your CV in English) Nice to have Experience with GraphQL

🏢 Summary: Offer for an experienced React FrontEnd Developer to design and build responsive, high-performance user interfaces in a hybrid model in Warsaw. The role focuses on developing modern web applications using React and related technologies, with strong emphasis on testing, accessibility, and performance optimization. The position involves close collaboration with cross-functional teams to deliver robust, user-centric digital products. 🗂️ Requirements: 6+ years of experience in JavaScript development, 6+ years of experience in TypeScript development, Commercial experience with React.js, Experience with Redux, Hands-on experience with HTML5, Hands-on experience with CSS3, Ability to write cross-browser compatible code, Understanding of object-oriented programming concepts and design patterns, Knowledge of functional programming paradigms, Understanding of asynchronous programming, Experience with TDD, Experience with continuous integration, Knowledge of Git and branch management, Experience with front-end debugging tools, Experience working in Agile methodology 📃 Skills: JavaScript, TypeScript, React, Redux, Next.js, HTML5, CSS3, Git, TDD, CI, OOP, FP 🏢 Description: React FrontEnd Developer IT · Warsaw (City Center) · Hybrid About the Client Our Client is a fast-growing, international technology company that provides innovative digital solutions for the global market. They are currently expanding and developing their R&D center in Warsaw. They are a leader in AI-powered enterprise operations, delivering digital solutions and consulting services that drive value and transform businesses. They specialize in using advanced technology to streamline operations, improve efficiency, and unlock new revenue opportunities, particularly within the private capital markets. With over a decade of experience supporting high-growth companies, they bring deep domain expertise and a proven ability to turn technology into a strategic advantage. Role Overview We are seeking a skilled React FrontEnd Developer to design and develop responsive user interfaces. In this role, you will collaborate with cross-functional teams to deliver robust, user-centric solutions while driving best practices in testing, accessibility, and performance optimization. Key Responsibilities UI Development: Designing and developing responsive user interfaces using React Testing & Integration: Implementing and maintaining TDD in applications and continuous integration. Driving best practices in testing, accessibility, and performance optimization. Collaboration: Collaborating with a cross-functional team of project managers, project analysts, and sales staff to deliver high-quality, interactive products on time. Collaborating cross-functionally with design, backend, QA, and product teams to deliver robust and user-centric solutions. Requirements & Qualifications Experience & Education: 6+ years of experience in JavaScript and TypeScript development. A Bachelor's degree in Computer Science or equivalent is preferred. Core Tech Stack: Must know a modern front-end JS framework, such as React.js + Redux; Next.js is a bonus. Hands-on experience with HTML5, CSS3. Proficiency in writing cross-browser compatible code. Programming Paradigms: Should understand OO concepts and design patterns, and their application to JavaScript development. Knows functional programming paradigms. Understands asynchronous programming paradigms and best practices. Tools & Debugging: Git and branch management knowledge. Experience debugging front-end problems and a knowledge of front-end debugging tools. Familiarity with custom package creation and integration. Soft Skills & Methodology: Experience with Agile methodologies and development practices. Good communication skills and good organization skills. Ability to work under pressure and deliver against tight deadlines. What Is Offered Compensation: Monthly compensation up to $4,800 USD . Contract Type: B2B contract via Optiveum. Work Model: Hybrid (3 days working from the office located in the center of Warsaw, 2 days working from home). Stability: Long-term cooperation with a stable, international organization.