Senior Software Engineer ( Ruby on Rails)

🏢 Summary: Full-time Senior Software Engineer role focused on building and scaling a Ruby on Rails-based platform used by solar professionals to design and sell solar projects. The position involves developing secure, high-performance backend services, reliable APIs, and contributing to frontend features in a distributed, hybrid work environment. The engineer will also support agile delivery, system ownership, and technical mentorship. 🗂️ Requirements: 5+ years of professional software engineering experience, Strong proficiency in Ruby on Rails, Experience with React and component-based frontend development, Working knowledge of JavaScript or TypeScript, Experience designing and maintaining APIs, Experience building secure, scalable backend systems, Ability to work in distributed, remote environment, Strong English communication skills 📃 Skills: Ruby, Rails, React, JavaScript, TypeScript, GraphQL, API, Backend, Agile 🏢 Description: Senior Software Engineer (Ruby on Rails) 💰 Salary: 19,000-28,000 PLN 🌎 Hybrid (2 days on site) ☑️ Full-time 🕦 Contract through Deel We’re looking for a Senior Software Engineer for a leading software provider in the clean-energy space, building technology that helps solar professionals design and sell solar projects accurately and at scale. Their platform has powered millions of solar designs and is recognized as one of the top remote-friendly and sustainability-focused companies in the industry. Requirements: 5+ years of professional software engineering experience. Strong proficiency with Ruby on Rails. Clear communication skills and comfort working cross-functionally. Familiarity with React and component-based frontend development. Working knowledge of JavaScript and/or TypeScript. Ability to thrive in a fully remote, distributed environment. Strong English skills (written and spoken). Nice to Have Experience with GraphQL . Interest in renewable energy, climate tech, or mission-driven products. Responsibilities: Build new features for a leading platform used by solar professionals for design and sales. Design and maintain reliable APIs that integrate smoothly with financial and sales partners. Develop secure, scalable backend services built for long-term stability and performance. Contribute to agile planning and help drive predictable, high-quality delivery. Mentor teammates, share knowledge, and strengthen the overall engineering culture. Take ownership of the services you build, including participating in on-call rotations. Benefits Health Coverage: Medical, dental, and vision insurance Internet & Mobile Stipend Work-From-Home Support (home office budget) Learning & Development support

🏢 Summary: Hybrid Software Engineer role focused on building and maintaining scalable solar technology platforms using Python or Ruby on Rails. The position involves developing APIs, collaborating across agile teams, and contributing to clean-energy products used by solar professionals worldwide. 🗂️ Requirements: 5+ years of professional software development experience, Experience with Python or Ruby on Rails, Experience delivering and maintaining production applications, Experience with React and component-based frontend development, Experience with JavaScript or TypeScript, Ability to collaborate across product, design, and engineering teams, Fluent written and spoken English 📃 Skills: Python, Ruby, Rails, React, JavaScript, TypeScript, GraphQL, API 🏢 Description: Salary: 21,000 - 27,000 PLN per month Hybrid from Warsaw (2 days on site / per week) Full-time Contract through Deel We’re looking for a Software Engineer for a leading software provider in the clean-energy space, building technology that helps solar professionals design and sell solar projects accurately and at scale. Their platform has powered millions of solar designs and is recognized as one of the top remote-friendly and sustainability-focused companies in the industry. Requirements: - At least 5 years of professional experience developing software - Hands-on experience delivering and maintaining real-world applications using Python OR Ruby on Rails - Strong communication abilities with a proven track record of working effectively across product, design, and engineering teams - Exposure to modern front-end development using React and reusable, component-driven architectures - Practical experience with JavaScript, TypeScript, or both in production environments - Fluent in written and spoken English Nice to Have: - Hands-on experience designing or working with GraphQL-based APIs - Interest in renewable energy, climate tech, or mission-driven products Responsibilities: - Design, build, and enhance features for an industry-leading solar design and sales platform - Develop and maintain APIs that integrate with financial and sales partners - Produce clean, well-structured, and maintainable code to support scalable and secure services - Work collaboratively within an agile team to deliver high-quality results in consistent sprint cycles - Participate in code reviews and team problem-solving to continuously raise code quality - Own the features and services you develop, including contributing to an on-call rotation with team support Benefits: - Health Coverage: Medical, dental, and vision insurance - Internet & Mobile Stipend - Work-From-Home Support (home office budget) - Learning & Development support

🏢 Summary: Full-time Senior Software Engineer role focused on designing and delivering scalable features and integrations for a renewable energy platform. The position involves building and maintaining large-scale systems, contributing to greenfield products, and supporting production services in a hybrid Warsaw setup. The goal is to enhance performance and automation in solar project development through robust software solutions. 🗂️ Requirements: 5+ years of software development experience, Proficiency in at least two production programming languages, Strong computer science fundamentals, Experience building and maintaining large-scale systems, Ability to work in remote or hybrid teams, Fluent English (spoken and written) 📃 Skills: Python, Java, Go, C++, JavaScript, TypeScript, Spring, Jackson, JPA, HTTP, SQL, MySQL, MariaDB, Git, Gradle, AWS, DDD 🏢 Description: Senior Software Engineer 💰 Salary: 14,000-28,000 PLN 🌎 Hybrid from Warsaw 🕦 Full-time position, long-term ☑️ Contract through Deel The company develops software that helps businesses plan and manage renewable energy projects more efficiently. Its technology platform uses data and automation to simplify complex workflows, enabling teams to design, evaluate, and deliver energy solutions at scale. The overall goal is to make clean energy projects easier to develop and deploy. Requirements: At least 5+ years of experience in software development Strong proficiency in at least two production programming languages (ideally Python and Java), though any combination of languages is acceptable Good engineering judgment based on solid computer science knowledge Experience working with teams to build and maintain large-scale systems Strong communication and collaboration skills, especially when working in remote or hybrid teams Comfortable adapting to changes in a growing product and evolving technology stack, with the ability to make practical decisions and support the team as things scale Fluent in spoken and written English (please submit your resume in English) Nice to Have: Interest in renewable energy and sustainability Experience applying Domain-Driven Design (DDD) principles Experience developing production software in at least one additional language besides Java (such as Python, Go, C++, JavaScript, or TypeScript) Familiarity with technologies such as Spring Framework, Jackson, JPA, HTTP, SQL (MySQL/MariaDB), Git, Gradle, and AWS Key Responsibilities: Design and deliver new features that improve the performance and accuracy of the platform Build integrations with key partners across the solar ecosystem to simplify end-to-end project workflows Develop new capabilities for our industry-leading solar design platform Lead the creation of new greenfield products that influence how solar systems are designed and implemented Take ownership of the services managed by your team, including participating in an on-call rotation for operational support Get to know DevsData: We are a technology consulting company and a recruitment agency, delivering software solutions to clients from Europe and the US. We work 100% remotely, in an international team, including people from Asia, London, or San Francisco. We employ people with experience in international corporations as well as students of the best technical and business universities. Find out more: https://devsdata.com/

🏢 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: Senior individual contributor engineering role focused on building and delivering scalable software, driving technical direction, solving complex problems, and mentoring engineers while remaining hands-on with development. The position involves working across backend and frontend systems using Ruby, Rails, React, PostgreSQL, Redis, Kafka, Elasticsearch, and Kubernetes. 🗂️ Requirements: Strong experience with Ruby, Experience leading complex cross-team projects, Ability to solve complex technical problems, Ability to work independently in ambiguous environments, Strong communication with technical and non-technical stakeholders, Experience mentoring engineers 📃 Skills: Ruby, Rails, PostgreSQL, Redis, React, Kafka, Elasticsearch, Kubernetes 🏢 Description: We are looking for a Senior Engineer to join our team and help us build and deliver software at scale. We have a flat structure, but this is a very senior individual role for someone who can make a big impact. In this role, you will take initiative, solve complex problems, improve our technical standards, and support other engineers. You will work closely with leadership to shape our technical direction while still writing code. Our Tech Stack Ruby 3.3.8 & Rails 7.2 PostgreSQL & Redis React (frontend) Kafka, Elasticsearch, Kubernetes (K8s) What you will do Drive technical work: Help turn high-level goals into clear projects and plans. Support the team: Mentor both junior and senior engineers to help them grow. Set standards: Improve how we work and make sure our code stays maintainable in the future. Handle uncertainty: Work without clear instructions at times, set direction, and guide others. Solve complex problems: Take the lead on difficult issues and important technical decisions. What we are looking for Strong experience with Ruby Experience in HR, Fintech, or Accounting systems is a plus Proven impact: experience leading complex projects across teams Good communication: able to work with both engineers and non-technical stakeholders Initiative: able to find important problems and follow through with solutions The process Screening call: 15-minute chat with a recruiter System design interview: 60-minute discussion about architecture Behavioral interview: 60-minute conversation about your experience and teamwork Final call: conversation with the CEO

🏢 Summary: Senior individual contributor role focused on building and delivering scalable software systems while shaping technical direction and standards. The position combines hands-on Ruby/Rails development with system design, cross-team technical leadership, and mentoring. The engineer will lead complex initiatives and drive architectural decisions in a modern distributed stack. 🗂️ Requirements: Strong experience with Ruby, Experience with Rails framework, Experience designing scalable systems, Proven experience leading complex cross-team technical projects, Ability to make architectural decisions, Experience mentoring engineers, Experience with distributed systems and backend integrations, Ability to work with PostgreSQL and Redis, Experience working with React frontend, Experience with Kafka, Elasticsearch, and Kubernetes 📃 Skills: Ruby, Rails, PostgreSQL, Redis, React, Kafka, Elasticsearch, Kubernetes, HR, Fintech, Accounting 🏢 Description: We are looking for a Senior Engineer to join our team and help us build and deliver software at scale. We have a flat structure, but this is a very senior individual role for someone who can make a big impact. In this role, you will take initiative, solve complex problems, improve our technical standards, and support other engineers. You will work closely with leadership to shape our technical direction while still writing code. Our Tech Stack Ruby 3.3.8 & Rails 7.2 PostgreSQL & Redis React (frontend) Kafka, Elasticsearch, Kubernetes (K8s) What you will do Drive technical work: Help turn high-level goals into clear projects and plans. Support the team: Mentor both junior and senior engineers to help them grow. Set standards: Improve how we work and make sure our code stays maintainable in the future. Handle uncertainty: Work without clear instructions at times, set direction, and guide others. Solve complex problems: Take the lead on difficult issues and important technical decisions. What we are looking for Strong experience with Ruby Experience in HR, Fintech, or Accounting systems is a plus Proven impact: experience leading complex projects across teams Good communication: able to work with both engineers and non-technical stakeholders Initiative: able to find important problems and follow through with solutions The process Screening call: 15-minute chat with a recruiter System design interview: 60-minute discussion about architecture Behavioral interview: 60-minute conversation about your experience and teamwork Final call: conversation with the CEO

🏢 Summary: Senior Frontend Engineer role focused on building and evolving a browser-based 3D design platform for modeling real-world physical systems. The position involves owning frontend features end-to-end, contributing to frontend architecture, collaborating across teams, and occasionally working with backend systems in a hybrid Warsaw-based setup. 🗂️ Requirements: 5+ years building production user interfaces in JavaScript and TypeScript, React experience, Knowledge of component-based frontend architecture, Experience integrating frontends with backend services and APIs, Ability to own features end-to-end, Willingness to work with backend code, Knowledge of system design, testing, refactoring, and technical writing, CS degree or equivalent production software experience, Fluent written and spoken English 📃 Skills: TypeScript, JavaScript, React, GraphQL, three.js, PostgreSQL, Ruby, Rails, Python, Playwright, Git, CAD 🏢 Description: Salary: 24,000 - 28,000 PLN/month Hybrid, Warsaw (2 Days/Week) Full-time Employment contract (UOP) via Employer of Record We're looking for a Senior Frontend Engineer for a software company whose platform lets professionals design real-world physical systems in an interactive, browser-based 3D environment. You'd join the team that owns the core of the product: the design surface where users model actual sites in a 3D canvas, backed by CAD tooling and a data model that keeps designs accurate to the physical world. Working stack: - TypeScript - JavaScript - React - GraphQL - three.js - PostgreSQL - Ruby on Rails - Python A senior individual contributor role reporting into engineering leadership. You'll own features end-to-end, from technical design through to production support, and help steer the frontend architecture the team relies on. Requirements: - 5+ years building production user interfaces in JavaScript and TypeScript - React experience and a firm grasp of component-based frontend architecture - Experience wiring frontends to backend services and APIs - Comfort owning features end-to-end, from scoping through to production - Willingness to step beyond the frontend when a feature calls for it, including reading and touching backend code (Ruby on Rails familiarity is a plus) - Engineering fundamentals: system design, testing, refactoring, and clear technical writing - A CS degree or an equivalent hands-on track record shipping production software - Fluent in written and spoken English Nice to Have: - GraphQL in production - three.js or another 3D graphics library - Ruby on Rails or Python - Playwright or a comparable end-to-end testing framework - Git in a collaborative, multi-engineer codebase - Any exposure to CAD software - Experience with distributed teams in a hybrid setup Key Responsibilities: - Build and ship frontend experiences that make designing faster and more accurate - Partner with Product, Design, and Engineering to scope, build, and release features - Write clean, well-tested code and raise the bar through code reviews and technical discussions - Strengthen reliability with automated tests and a share of the team's on-call rotation - Contribute to shared frontend architecture, tooling, and technical standards - Pick up backend work when it's needed to land the features you own - Support a collaborative engineering culture through mentoring, planning, and cross-team work

🏢 Summary: Senior Ruby on Rails Developer role focused on building and evolving a cloud-ready product into a scalable, distributed system. The position involves designing architecture, developing core services and APIs, and driving Kubernetes-based deployments with CI/CD automation. You will influence engineering standards and contribute production-ready code in a greenfield development environment. 🗂️ Requirements: 5+ years of software engineering experience, Senior-level Ruby on Rails expertise, Experience building and scaling distributed systems, Knowledge of Kubernetes, Experience with CI/CD pipelines, Experience with Infrastructure as Code, Strong API design skills, Experience with microservices communication, Ability to lead architectural initiatives, Mentoring experience for engineers 📃 Skills: Ruby, Rails, Kubernetes, CI/CD, IaC, API, Microservices, DistributedSystems 🏢 Description: We are looking for an experienced Senior Ruby on Rails Developer to join the team responsible for development of the product, which is evolving into a modern, cloud‑ready solution. In this role, you will have opportunity to influence architectural decisions, contribute production‑ready code, and collaborate closely with cross‑functional teams. Your daily responsibilities: Build and improve core platform services and APIs Design scalable, distributed system architecture Implement and optimize key components in the codebase Set engineering standards for reliability and maintainability Drive deployments using Kubernetes and CI/CD automation Collaborate across teams to align technical and product goals. Requirements: 5+ years of software engineering experience, including senior‑level work Strong proficiency in Ruby on Rails Experience building and scaling distributed systems Solid knowledge of Kubernetes, CI/CD, and IaC Strong skills in API design and microservice communication Ability to lead architectural initiatives and mentor other engineers. What we offer: Attractive salary and benefits package, including Multisport card, insurance, and medical care Hybrid work from the Krakow office International work environment in a product company Training and development opportunities within the organization Joining the greefield project with pure development. Apply now!

🏢 Summary: Full-time hybrid Software Engineer role focused on building responsive, AI-driven web applications for enterprise platforms using modern JavaScript technologies. The position involves developing high-quality React-based interfaces, applying TDD and CI practices, and collaborating within cross-functional Agile teams. Long-term B2B contract based in Warsaw with competitive salary. 🗂️ Requirements: 6+ years experience with JavaScript, 6+ years experience with TypeScript, Strong knowledge of design patterns in JavaScript, Proficiency in React with Redux, Experience with Next.js, Understanding of functional programming concepts, Strong knowledge of asynchronous programming, Experience with Git and branch management, Experience debugging front-end applications, Experience creating and integrating custom packages, Understanding of object-oriented programming principles, Practical experience with HTML5, Practical experience with CSS3, Experience in Agile environments, Ability to develop cross-browser compatible code 📃 Skills: JavaScript, TypeScript, React, Redux, Next.js, HTML5, CSS3, Git, TDD, CI, Agile 🏢 Description: 💰 Salary: 14,500-17,000 PLN/month 🌎 Hybrid from Warsaw, Poland 🕦 Full-time position, long-term ☑️ B2B We are looking for a Software Engineer to join our client, a technology company that builds AI-powered platforms and consulting solutions for enterprise operations, with a strong focus on the private capital sector. The company has over ten years of experience working with high-growth and PE-backed businesses, combining deep domain expertise with advanced technology to drive measurable results. Requirements: 6+ years of experience working with JavaScript and TypeScript Solid understanding of design patterns and how to apply them in JavaScript development. Proficiency in a modern front-end JavaScript framework such as React.js with Redux; experience with Next.js is an advantage. Familiarity with functional programming concepts. Strong grasp of asynchronous programming and its best practices. Knowledge of Git and experience with branch management. Experience troubleshooting front-end issues and using relevant debugging tools. Familiarity with creating and integrating custom packages. Good understanding of object-oriented programming principles and their use in JavaScript. Ability to perform effectively under pressure and meet strict deadlines. Practical experience with HTML5 and CSS3. Experience working within Agile development environments and practices. Strong communication and organizational abilities. Skilled in developing cross-browser compatible code. A Bachelor’s degree in Computer Science or a related field is preferred. Key Responsibilities: Creating and building responsive user interfaces using React. Applying and maintaining test-driven development (TDD) practices along with continuous integration processes. Working closely with a cross-functional team that includes project managers, analysts, and sales representatives to deliver high-quality, interactive products within deadlines. Promoting and implementing best practices in testing, accessibility, and performance optimization. Partnering with design, backend, QA, and product teams to develop reliable, user-focused solutions.

🏢 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