Senior Software Engineer (Python)

🏢 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: Full-time Team Lead Software Engineer role focused on leading a full-stack team building high-performance web applications using React and Node.js. The position combines hands-on development with architectural ownership, mentoring, and delivery of scalable, AI-powered enterprise platforms. Work involves designing microservices, APIs, and cloud-based containerized deployments in a hybrid setup from Warsaw. 🗂️ Requirements: 7+ years full-stack experience with React.js and Node.js in production, 2+ years in Team Lead or senior engineering leadership role, Strong knowledge of React ecosystem (Redux, Hooks, component architecture, performance optimization), Proficiency in HTML5, CSS3, JavaScript ES6+, Experience with build tools (Webpack, Vite, or Babel), Experience with Express.js and RESTful API design, Knowledge of OAuth, JWT, session-based authentication, Experience with PostgreSQL or MySQL, Experience with MongoDB or other NoSQL databases, Hands-on experience with Docker, Familiarity with AWS or other major cloud platform, Experience with Git and Agile/Scrum methodologies 📃 Skills: React, Redux, JavaScript, HTML5, CSS3, Node.js, Express, REST, GraphQL, OAuth, JWT, PostgreSQL, MySQL, MongoDB, Docker, Kubernetes, AWS, Git, Webpack, Vite, Babel, Agile, Scrum 🏢 Description: 💰 Salary: 29,500–33,200 PLN/month 🌎 Hybrid from Warsaw, Poland 🕦 Full-time position, long-term ☑️ Contract of Employment We are looking for a Team Lead 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. In this role, the focus will be on leading a team of developers across front-end and back-end development, owning architectural decisions, and contributing directly to the codebase. You will mentor engineers and drive the delivery of high-performance web applications using React and Node.js. Requirements 7+ years of full-stack development experience with React.js and Node.js in production environments 2+ years in a team lead, tech lead, or senior engineering leadership role Strong command of the React ecosystem: Redux, React Hooks, component architecture, and performance optimization Solid HTML5, CSS3, and modern JavaScript (ES6+); experience with build tooling such as Webpack, Vite, or Babel Proficiency with Express.js and API design (RESTful; GraphQL is a plus) Working knowledge of auth patterns: OAuth, JWT, session-based authentication Hands-on experience with PostgreSQL or MySQL; familiarity with MongoDB or similar NoSQL databases Docker experience required; Kubernetes is a plus Familiarity with at least one major cloud platform (AWS preferred) Comfortable with Git workflows and Agile/Scrum delivery Responsibilities Lead and mentor a team of software engineers; run code reviews, set engineering standards, and hold the bar on quality Architect and build full-stack features using React.js (with Redux and Hooks) on the front end and Node.js / Express.js on the back end Design scalable microservices and RESTful (or GraphQL) APIs aligned with product requirements Own the testing strategy: define coverage expectations, enforce unit and integration testing, and integrate quality gates into CI/CD pipelines Manage containerized deployments via Docker; collaborate on infrastructure with cloud platforms (AWS, Azure, or GCP) Partner directly with Product and Design to translate requirements into production-grade, accessible interfaces Model and maintain SQL and NoSQL data schemas; own data interaction patterns across services Monitor production systems, triage incidents, and drive root-cause resolution Keep technical documentation accurate and up to date 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. We employ people with experience in international corporations as well as the ones from the best technical and business universities. Find out more: https://devsdata.com

🏢 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: Full-time remote engineering role focused on developing and scaling a SaaS platform that delivers digital identity records for physical products via QR codes. The position involves building and extending a Django-based backend, creating React/TypeScript front-end features, and designing data pipelines integrating external product systems. The engineer will also contribute to cloud infrastructure reliability and architectural decisions as the platform grows. 🗂️ Requirements: 5+ years of hands-on software engineering experience, Advanced Python and Django expertise, Strong TypeScript and React proficiency, Experience with REST APIs and webhooks, Experience processing JSON, XML, CSV data formats, Experience with Google Cloud Platform or AWS or Azure, Experience using AI-assisted development tools (e.g., Claude, GitHub Copilot), Advanced English proficiency 📃 Skills: Python, Django, TypeScript, React, Tailwind, REST, Webhooks, JSON, XML, CSV, GCP, AWS, Azure, Claude, Copilot 🏢 Description: 💰 Salary: 19 100 - 23 400 PLN per month 🌎 100% remote 🕦 Full-time position, long-term ☑️ B2B Contract The company operates a SaaS platform that lets brands create and administer digital identity records for their physical goods. Shoppers reach these records by scanning QR codes on items such as apparel or footwear, landing in branded interfaces that surface sustainability data, maintenance guidance, after-sales support, and secondary market options. The product ingests existing product data from brand clients and makes it consumable at scale. Requirements: At least 5+ years of hands-on engineering experience, combined with solid product thinking Advanced Python capability, since Django carries most of the platform's business logic Confident working knowledge of TypeScript, React, and Tailwind CSS Practical background integrating REST endpoints and webhooks, plus experience parsing inconsistent production data in formats such as JSON, XML, and CSV Direct exposure to Google Cloud Platform, or transferable depth in AWS or Azure Daily use of AI-assisted development tools such as Claude or GitHub Copilot as part of standard workflow Advanced spoken and written English Nice to Have: Prior work with enterprise resource planning or product information management systems, for instance SAP, Akeneo, or inRiver Exposure to GS1 specifications or other supply chain data interchange formats Key Responsibilities: Extend and refine the Django-based Python backend through new API endpoint development, data model changes, background job processing, and performance tuning Build and maintain the APIs that power the Passport Builder product Deliver user-facing functionality written in TypeScript and React within the Passport Builder and the administrative tools used by brand teams Take responsibility for uptime and monitoring on GCP infrastructure, spotting anomalies ahead of customer-reported incidents Contribute to technical direction and shape architectural choices as the platform expands across additional clients, larger product catalogs, and new geographic regions Architect and implement data pipelines that move ERP, PLM, and PIM records from client systems into the platform during new brand onboarding 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: Full-time Senior Full Stack Developer role focused on building scalable, data-driven platforms for financial and enterprise sectors using Node.js and React. The position involves designing microservices, developing RESTful APIs, and creating responsive front-end applications in a hybrid work model (Warsaw). 🗂️ Requirements: 5+ years experience as Senior Full Stack Developer, Strong expertise in Node.js, Strong expertise in React, Experience with Express.js, Experience building RESTful or GraphQL APIs, Knowledge of OAuth and JWT authentication, Proficiency in Redux, HTML5, CSS3, ES6+, Experience with Vite, Webpack or Babel, Experience with MySQL or PostgreSQL, Experience with AWS, Azure or GCP, Experience with Docker and Kubernetes, Proficiency with Git 📃 Skills: Node.js, React, Express.js, GraphQL, REST, OAuth, JWT, Redux, HTML5, CSS3, JavaScript, ES6, Vite, Webpack, Babel, MySQL, PostgreSQL, AWS, Azure, GCP, Docker, Kubernetes, Git, SQL, MongoDB, CI/CD 🏢 Description: Senior Full Stack Developer (Node.js + React) 💰 Salary: 23,000-24,800 PLN/Month 💻 Warsaw, Poland (Hybrid - 3 days in office, 2 days remote) 🕦 Full-time ☑️ B2B or CoE We’re looking for a Senior Full-Stack Developer to join a fast-growing international tech company focused on building modern, data-driven platforms that power digital transformation in the financial and enterprise sectors. Requirements: 5+ years of experience as a Senior Full Stack Developer with significant expertise in Node.js and React. Strong experience in building server-side applications using Node.js and Express.js. Hands-on experience with API development and integration, particularly with GraphQL or RESTful services. Strong knowledge of authentication and authorization mechanisms (OAuth, JWT, session-based). Front-end proficiency in React.js, Redux, HTML5, CSS3, and modern JavaScript (ES6+). Familiarity with front-end build tools such as Vite, Webpack, and Babel. Strong experience with databases such as MySQL and  PostgreSQL. Experience with cloud platforms (AWS, Azure, or GCP), as well as containerization and orchestration tools such as Docker and Kubernetes. Strong experience using Git and version control systems. Proficiency in English (both written and spoken). Key Responsibilities: Design, build, and maintain scalable, high-performance server-side applications and RESTful APIs using Node.js and Express.js. Develop and maintain interactive, responsive user interfaces using React.js, Redux, and modern JavaScript (ES6+). Lead the design and implementation of scalable architectures and microservices. Work closely with database engineers to design efficient schemas and manage data interactions using SQL databases or MongoDB. Ensure reliable deployments and smooth release of updates using CI/CD pipelines and Docker. Write unit and integration tests and optimize performance to ensure high-quality code. Collaborate closely with cross-functional teams to define and implement technical solutions. Improve system performance, reliability, and long-term maintainability through optimization and best practices. 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: Full-time Senior Back-End Engineer (Node.js) role focused on designing and maintaining scalable, high-performance server-side applications and APIs for modern, data-driven platforms. The position involves building RESTful services, integrating with third-party systems, ensuring code quality through testing, and optimizing system reliability and performance. Hybrid work model in Warsaw with B2B or CoE contract options. 🗂️ Requirements: Strong experience with Node.js, Strong experience with Express.js, Experience building and integrating APIs (GraphQL or REST), Knowledge of OAuth, JWT, and session-based authentication, Experience with MySQL, Experience with PostgreSQL, Experience writing unit tests with Chai and Mocha, Experience using Git and version control systems 📃 Skills: Node.js, Express.js, GraphQL, REST, OAuth, JWT, MySQL, PostgreSQL, Chai, Mocha, Git 🏢 Description: Senior Back-End Engineer (Node.js) 💰 Salary: 18,700-20,900 PLN/Month 💻 Warsaw, Poland (Hybrid - 3 days in office, 2 days remote) 🕦 Full-time ☑️ B2B or CoE We’re looking for a Senior Back-End Engineer to join a fast-growing international tech company focused on building modern, data-driven platforms that power digital transformation in the financial and enterprise sectors. Requirements: Strong experience in building server-side applications using Node.js and Express.js. Hands-on experience with API development and integration, particularly with GraphQL or RESTful services. Strong knowledge of authentication and authorization mechanisms (OAuth, JWT, session-based). Strong experience with databases such as MySQL and  PostgreSQL. Experience writing unit tests with tools such as Chai and Mocha. Strong experience using Git and version control systems. Proficiency in English (both written and spoken). Nice To have: Bachelor’s degree in Computer Science or a related field. Experience with cloud platforms (AWS, Azure, or GCP), as well as containerization and orchestration tools such as Docker and Kubernetes. Experience with microservices architecture. Experience setting up CI for static analysis and test execution. Experience developing RAG applications and storing data in vector embeddings. Key Responsibilities: Design, build, and maintain scalable, high-performance server-side applications and RESTful APIs using Node.js and Express.js. Guide and supervise the development of key code components to ensure long-term reliability and scalability. Integrate with front-end components and third-party services. Actively review the codebase, recommending and implementing refinements where needed. Write unit and integration tests and optimize performance to ensure high-quality code. Collaborate closely with cross-functional teams to define and implement technical solutions. Improve system performance, reliability, and long-term maintainability through optimization and best practices. 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: Full-time Full Stack Software Engineer role focused on building AI-powered enterprise platforms using Java and React in a hybrid Warsaw setup. The position involves developing responsive front-end applications and scalable microservices-based back-end systems, integrating cloud services, and maintaining CI/CD pipelines. Long-term employment contract with emphasis on high-performance, secure, and maintainable solutions. 🗂️ Requirements: 5+ years experience as Full Stack Developer with Java and React.js, Strong proficiency in React.js and Redux, Strong knowledge of TypeScript, HTML5, CSS3, ES6+, Experience with state management and component-based architecture, Experience with UI libraries (Material-UI, Bootstrap, or Tailwind), Strong expertise in Java, Spring Boot, Hibernate, JPA, Experience building RESTful APIs and microservices, Knowledge of OAuth2, JWT, and session-based authentication, Experience with PostgreSQL or MySQL, Experience with MongoDB or Redis, Hands-on experience with CI/CD tools, Experience with AWS, Azure, or GCP, Experience with Docker and Kubernetes, Bachelor’s or Master’s degree in Computer Science or related field, Experience working in Agile environments 📃 Skills: Java, React, Redux, TypeScript, HTML5, CSS3, JavaScript, Spring, SpringBoot, Hibernate, JPA, REST, Microservices, OAuth2, JWT, PostgreSQL, MySQL, MongoDB, Redis, Jenkins, GitHub, GitLab, AWS, Azure, GCP, Docker, Kubernetes 🏢 Description: 💰 Salary: 21,000-22,000 PLN/month 🌎 Hybrid from Warsaw, Poland 🕦 Full-time position, long-term ☑️ Contract of Employment 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: 5+ years of professional experience as a Full Stack Developer working with Java and React.js. Strong proficiency in React.js, Redux, TypeScript, HTML5, CSS3, and modern JavaScript (ES6+). In-depth understanding of state management solutions and component-based design principles. Experience working with UI libraries/frameworks such as Material-UI, Bootstrap, or Tailwind CSS. Solid expertise in Java, Spring Boot, Hibernate, JPA, and building RESTful APIs. Experience designing and working with microservices architecture and API Gateway patterns. Knowledge of authentication and authorization approaches, including OAuth2, JWT, and session-based methods. Experience with relational databases (PostgreSQL, MySQL) as well as NoSQL solutions (MongoDB, Redis). Hands-on experience using CI/CD tools like Jenkins, GitHub Actions, or GitLab CI/CD. Familiarity with cloud platforms such as AWS, Azure, or GCP, along with containerization tools like Docker and Kubernetes. Bachelor’s or Master’s degree in Computer Science, Engineering, or a related discipline. Experience operating within Agile development environments. Strong analytical thinking and problem-solving abilities. Key Responsibilities: Build and develop dynamic, responsive, and high-performing user interface components using React.js, Redux, and modern JavaScript (ES6+). Ensure applications function consistently across different browsers while delivering a smooth user experience. Enhance front-end performance and apply best practices in UI/UX design. Design, develop, and maintain RESTful APIs and microservices using Java technologies such as Spring Boot, Hibernate, and JPA. Implement secure authentication, authorization, and effective data management solutions. Work with both relational and NoSQL databases, including PostgreSQL, MySQL, and MongoDB. Integrate external services, APIs, and cloud-based platforms into applications. Oversee deployment processes using CI/CD pipelines and containerization technologies like Docker and Kubernetes. Produce clean, efficient, and maintainable code in line with established best practices. Develop and maintain unit and integration tests for both front-end and back-end systems. Collaborate closely with UI/UX designers, product managers, and DevOps specialists. Take part in Agile/Scrum processes and support ongoing improvements to development workflows.

🏢 Summary: Senior Backend Developer role focused on designing and delivering scalable server-side applications and APIs using Python and Django for early-stage B2B SaaS products. The position involves architectural ownership, system reliability, and performance optimization in a fully remote, full-time setup. The developer will drive backend best practices, testing, and CI/CD processes. 🗂️ Requirements: 5+ years of backend development experience, Extensive experience with Python, Extensive experience with Django, Proficiency in data modelling, Experience with relational databases, Experience with non-relational databases, Ability to write complex SQL queries, Experience with API design, Experience with system integrations, Experience with distributed systems (synchronous and asynchronous), Hands-on experience with Docker, Hands-on experience with Redis, Experience with message brokers, Experience with cron jobs, Experience writing unit tests (e.g. Pytest), Strong understanding of code quality and testing best practices, Good command of English for technical communication 📃 Skills: Python, Django, SQL, Docker, Redis, Pytest, APIs, Databases, PostgreSQL, MongoDB, CI/CD, MessageBroker, Cron, Git 🏢 Description: Senior Backend Developer (Python/Django; 100% remote) 💰 Salary: 23,400-25,500 PLN/month 🌎 100% Remote 🕦 Full-time position ☑️ B2B or Contract of Employment We are looking for a Senior Backend Developer for a partner client with a compelling mission: they act as a product and technology partner for early-stage B2B SaaS founders, helping them navigate the crucial journey from launch to their first million in revenue. They essentially become the dedicated tech backbone for these startups. Requirements: 5+ years of professional backend development experience. Extensive, proven experience with Python and the Django framework. Proficient in data modelling, relational and non-relational databases, and complex SQL queries. Strong experience with API design, integrations, and distributed systems (synchronous & asynchronous communication). Hands-on experience with Docker, Redis, message brokers, and cron jobs. Expertise in writing unit tests (e.g., Pytest) and a commitment to code quality and testing best practices. Great understanding of English with strong communication and collaboration skills. Nice to have: Previous experience in Greentech or Ecotech is a significant plus. Experience as an unofficial tech lead or mentoring junior developers. Knowledge of additional testing methodologies (integration, end-to-end). Responsibilities: Lead the design and development of complex server-side applications, APIs, and databases, taking ownership of architectural decisions. Architect, write, and deliver high-quality, scalable, and efficient code using Python and Django. Collaborate closely with cross-functional teams, including front-end developers and the tech lead, to align backend development with project goals. Architect and implement advanced user authentication, authorisation, and security mechanisms. Conduct performance analysis and optimisation, identifying bottlenecks and implementing solutions. Drive the implementation of automated testing and CI/CD processes to ensure code reliability. Establish and enforce coding standards, conduct thorough code reviews, and document backend architecture and APIs. Take responsibility for system reliability, scalability, and security, ensuring best practices. 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: Full Stack Developer role focused on building and modernizing a cloud-based SaaS platform in Microsoft Azure for managing and optimizing district heating and energy systems. The position involves end-to-end development across Node.js backend services and React frontend applications, working with real-time data, integrations, and distributed cloud environments. The offer includes ownership of features from development to production in a quality-driven, Agile team. 🗂️ Requirements: Minimum 3 years commercial experience as Full Stack Developer, Strong experience with Node.js and TypeScript, Strong experience with React and TypeScript, Experience building and maintaining REST APIs, Experience with MySQL and MongoDB, Experience with InfluxDB, Experience with automated unit and integration testing, Experience with Git and pull request workflows, Ability to work within large existing codebases, Understanding of safe data operations and data integrity, Experience working in Agile/Scrum environments, Good written and spoken English 📃 Skills: Node.js, TypeScript, React, REST, MySQL, MongoDB, InfluxDB, MQTT, Docker, Kubernetes, Azure, AzureDevOps, CI/CD, YAML, Grafana, Sentry, Cypress, Git, pnpm 🏢 Description: Salary: 700 - 850 PLN/MD on B2B Work model: hybrid from Gdańsk / Warszawa / Kraków / Rzeszów Why choose this offer? Work on a modern SaaS platform hosted in the cloud (including Microsoft Azure), used to manage and optimize district heating and energy systems Join a distributed team working across the full technology stack, from backend services to frontend applications Take ownership of features from development through production deployment Work in an environment that values automated testing, code quality, and peer code reviews Contribute to a platform with a real-world impact on energy efficiency and operational optimization Project The project is a cloud-based SaaS platform hosted in Microsoft Azure that supports the management and optimization of district heating networks, heating substations, and other components of heating infrastructure. The application collects and processes data from meters, sensors, network measurements, and controllers, enabling remote monitoring, configuration, and control of connected devices. It provides real-time and historical analysis of energy consumption and operational parameters , along with reporting, alerting, dashboards, maps, and data visualizations that help operators efficiently oversee entire heating networks. The platform also integrates with external data sources, such as weather forecasts and optimization systems, to improve operational efficiency and decision-making. The successful candidate will initially focus on modernizing and improving internal tools before moving into feature development and platform-related initiatives. The role involves broad full-stack development across Node.js backend services and React-based frontend applications, working within a large, established codebase and contributing to solutions used in a distributed, cloud-native environment. Expected competences and knowledge Minimum 3 years of commercial experience as a Full Stack Developer working with Node.js, TypeScript and React Strong experience with Node.js and TypeScrip t for building and maintaining backend services and REST APIs Strong experience with React and TypeScript , including modern hooks-based development and component design Experience working with MySQL, MongoDB, and ideally InfluxDB , with a solid understanding of data modelling, querying, performance optimization, and maintaining data integrity across relational and document databases Ability to work effectively within a large existing codebase, following established patterns and safely extending applications and services built by other engineers Practical experience with automated testing , including unit and integration testing as a standard part of the development process Experience working with Git and pull request-based workflows , including participating in code reviews and providing constructive feedback Understanding of safe and reliable data operations , including idempotency, handling partial failures, and minimizing risks associated with data modifications Good written and spoken English skills , enabling effective collaboration within a distributed, international team Experience working in Agile/Scrum environments , including estimation, stand-ups, sprint planning, and sprint commitments Proactive, self-organized approach to work , with the ability to identify and communicate blockers early Strong ownership mindset and accountability for delivering features from development through production Nice to have: Experience with microservices and event-driven architectures, including message brokers, queues, and pub/sub patterns Familiarity with MQTT and systems processing telemetry or IoT device data Experience with Docker and basic knowledge of Kubernetes Experience working in monorepo environments and with pnpm workflows Familiarity with Microsoft Azure and Azure DevOps CI/CD pipelines Understanding of observability concepts, including logs, metrics, and traces, with tools such as Grafana and Sentry Experience with Cypress or other end-to-end testing frameworks Experience with event sourcing architectures Knowledge of IoT, industrial protocols, or domains such as energy management, district heating, building management systems, or smart infrastructure solutions Technologies you'll work with Node.js TypeScript React REST APIs MySQL MongoDB InfluxDB MQTT Job Queues Docker Kubernetes pnpm Monorepo Architecture Microsoft Azure Azure DevOps CI/CD Pipelines (YAML) Grafana Sentry Cypress Git Automated Testing (Unit, Integration, E2E) Client – why choose this particular client from the Jit portfolio? Our Client engineers technologies that enable the world of tomorrow to do more with less. They meet the growing need for infrastructure, food supply, energy efficiency and climate-friendly solutions . Their products and services are used in areas such as refrigeration, air conditioning, heating, motor control and mobile machinery. They are also active in the field of renewable energy as well as district heating infrastructure for cities and urban communities. Their innovative engineering dates back to 1933 and today our Client is a world-leader , employing more than 27,000 employees and serving customers in more than 100 countries . They are still privately held by the founding family. About Jit Team The Human Factor of IT - it’s not just a slogan, it’s a philosophy. The foundation of Jit Team is people, which is why we prioritise you. We employ over 770 experienced experts , to whom we offer developmental projects, a wide range of benefits, and a proprietary professional development programme. Together with clients from around the world, we create innovative IT solutions delivered by highly specialised and efficient teams. Behind our maxim are also charitable and educational activities. We support schools, universities, and educational institutions by conducting workshops, running educational projects, sponsoring events, and donating learning equipment. We offer internships that help launch careers in IT. We support water rescuers and hospitals by providing the necessary equipment. We also support numerous charitable organisations helping people in need, children, and the elderly. We are a Polish company and we share what we have achieved over more than 15 years of activity. By supporting local initiatives, we contribute to the circulation of good energy.

🏢 Summary: Full-time hybrid Associate Frontend Team Lead role focused on leading a React development team, owning frontend architecture, and delivering high-performance web applications. The position combines hands-on coding with mentorship and technical leadership in building scalable, enterprise-grade AI-driven platforms. You will drive best practices in frontend design, state management, testing, and performance optimization. 🗂️ Requirements: 5+ years experience with JavaScript and TypeScript, Minimum 3 years experience with React.js, Strong proficiency in React Hooks and Context API, Experience with Redux and Redux Toolkit, Knowledge of frontend design patterns and clean code practices, Experience integrating REST or GraphQL APIs, Proficiency in HTML5, CSS3, SCSS, Experience with responsive UI development, Hands-on experience with component libraries and design systems, Familiarity with Webpack or Vite, Experience leading or mentoring developers, Experience with unit and integration testing 📃 Skills: JavaScript, TypeScript, React, ReactHooks, ContextAPI, Redux, ReduxToolkit, HTML5, CSS3, SCSS, REST, GraphQL, Webpack, Vite, Storybook, MaterialUI, Tailwind, Next.js, Jest, ReactTestingLibrary, Lighthouse, ChromeDevTools, WCAG, CICD 🏢 Description: 💰 Salary: 25,000-29,500 PLN/month 🌎 Hybrid from Warsaw, Poland 🕦 Full-time position, long-term ☑️ Contract of Employment We are looking for an Associate Frontend Team Lead 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. In this role, the focus will be on leading a team of developers across front-end development, owning architectural decisions, and contributing directly to the codebase. You will mentor engineers and drive the delivery of high-performance web applications. Requirements: 5+ years of experience with JavaScript/TypeScript, including at least 3 years working with React.js Strong proficiency in React Hooks, Context API, and Redux (preferably Redux Toolkit) Demonstrated understanding of frontend design patterns and clean coding practices Experience integrating frontend applications with RESTful APIs or GraphQL services Solid knowledge of HTML5, CSS3/SCSS, and building responsive user interfaces Hands-on experience with component libraries and design systems (e.g., Storybook, Material UI, Tailwind) Familiarity with modern build tools such as Webpack and Vite, including optimization techniques Experience leading or mentoring developers within a team environment Nice to Have: Familiarity with performance analysis and profiling tools (e.g., Lighthouse, Chrome DevTools) Experience working with SSR/SSG frameworks like Next.js Understanding of web accessibility standards (WCAG) Contributions to open-source frontend projects or libraries Key Responsibilities: Guide and support a team of React developers through code reviews, one-on-one meetings, and practical coaching. Work closely with product managers, designers, and backend engineers to shape and prioritize features. Take ownership of sprint planning, task estimation, and meeting delivery deadlines for the frontend team. Design and build sophisticated user interfaces using React, including Hooks and the Context API. Develop and maintain a scalable state management approach using Redux Toolkit. Apply and promote modern frontend design patterns such as container/presenter, compound components, render props, and higher-order components. Create reusable components and ensure consistency with the overall design system. Improve application performance, accessibility, and compatibility across different browsers. Champion best practices for code quality, testing, CI/CD processes, and documentation. Ensure strong unit and integration test coverage using tools like Jest and React Testing Library. Participate in frontend architecture decisions and assess new tools and libraries when appropriate. 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.