Senior Software Engineer (React, React Native & Node.js)

🏢 Summary: Senior Full Stack Engineer role focused on building and delivering scalable, mission-critical applications using Node.js and React. The position involves end-to-end ownership from design and architecture to deployment and production support within Agile environments. The role requires strong technical leadership, architectural involvement, and collaboration with cross-functional and customer-facing teams. 🗂️ Requirements: Minimum 6 years of commercial Full Stack development experience, Strong knowledge of Node.js and React, Proficiency in JavaScript and TypeScript, Experience working in Agile environments, Experience with AWS and Docker, Experience with PostgreSQL, Experience with Git or Bitbucket and Jenkins, Familiarity with REST APIs and GraphQL, Knowledge of SQL and NoSQL databases, Understanding of software architecture, design patterns, and SOLID principles, Experience with SDLC processes end-to-end, Fluency in English (minimum B2), Master’s degree in Computer Science, Software Engineering, or related field 📃 Skills: JavaScript, TypeScript, Node.js, React, AWS, Docker, PostgreSQL, Git, Bitbucket, Jenkins, REST, GraphQL, SQL, NoSQL, Azure, ReactNative, Expo 🏢 Description: About Webellian Webellian is a well-established Digital transformation and IT consulting company committed to creating a positive impact for our clients. We are driven by shared values, strong principles, and a passion for innovative and disruptive technologies. We are a community of engineers and senior advisors who work with our clients across industries, playing a deep and meaningful role in accelerating and realizing their vision and strategy. About the job We are actively looking for a Senior Full Stack Engineer (Node.js & React). In this role, you will own technical responsibilities from conception to delivery. As a Senior Full Stack Engineer, you will collaborate closely with engineering teams, interact directly with customers and stakeholders, work on mission-critical systems at scale, and support the SDLC process end-to-end. This role requires a strong ownership mindset and readiness to take technical responsibility for project delivery, including participation in architectural discussions and technical decision-making. To be successful in this position, you should have at least 6 years of commercial experience in Full Stack development, strong understanding of Node.js, React, and related frameworks, and experience working within Agile engineering environments. Key responsibilities Analyze business and technical functional and non-functional requirements Design and develop clean, maintainable, and scalable code, including unit tests Prepare and maintain technical documentation Propose and implement technical improvements to applications and development processes Participate in troubleshooting and resolving complex technical issues Collaborate with other engineering teams to design and implement technical solutions Contribute to architectural and technical decision-making processes Support SDLC activities end-to-end, including development, testing, deployment, and production support Take ownership of technical delivery Competencies Master’s degree in Software Engineering, Computer Science, or related technical field Must-have Technologies: JavaScript, TypeScript, Node.js, React Advantage: React Native, Expo, Microsoft Azure Fluency in English is required (minimum B2, C1 preferred) Excellent verbal and written communication skills Experience working with AWS, Docker, PostgreSQL, Git/Bitbucket, and Jenkins Familiarity with REST APIs and GraphQL Familiarity with SQL and NoSQL databases Strong understanding of Agile methodologies and SDLC practices Understanding of software architecture trade-offs, scalability considerations, design patterns, and SOLID principles Leadership mindset: previous experience in technically leading projects, participating in architectural decision-making, and taking responsibility for the technical delivery process Experience working in customer-facing or international environments Nice to have Experience with CI/CD pipelines and deployment automation for web and mobile applications (e.g., EAS Build for Expo) Experience in scaling applications and handling high-traffic workloads Experience with cloud-native architectures and distributed systems Familiarity with monitoring, observability, and production troubleshooting practices Experience in fintech or insuretech environments What we offer Contract under Polish law: B2B or Umowa o Pracę Benefits such as private medical care, group insurance, Multisport card There are English classes available Hybrid work (at least 3 days/week on-site) in Warsaw (Mokotów) Opportunity to work with excellent professionals High standards of work and focus on the quality of code New technologies in use Continuously learning and growth International team Pinball, PlayStation & much more (on-site 🤫) Interested? Please click the “Apply for this job” button and send us your CV in English. Please include the following statement: I hereby authorize Webellian Poland Sp. z o.o. to the process personal data provided in this document for realising the recruitment process pursuant to the Personal Data Protection Act of 10 May 2018 (Journal of Laws 2018, item 1000) and in agreement with Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016 on the protection of natural persons with regard to the processing of personal data and on the free movement of such data, and repealing Directive 95/46/EC (General Data Protection Regulation).

🏢 Summary: Senior Fullstack Engineer role focused on building and enhancing client solutions using Node.js and React technologies, including a back-office platform for a global insurance leader. The position involves fullstack development, technical analysis, clean code delivery, mentoring junior developers, and collaboration with international teams in a hybrid Warsaw-based environment. 🗂️ Requirements: 5+ years of Fullstack development experience, Master’s degree in Software Engineering or related field, Strong knowledge of Node.js and React, Experience with related frontend and backend frameworks, Experience writing unit tests and technical documentation, Understanding of software architecture and development principles, Familiarity with REST API and GraphQL, Knowledge of SQL and NoSQL databases, Fluent English level B2 minimum, Excellent verbal communication skills 📃 Skills: Node.js, React, ReactNative, Next.js, Redux, TypeScript, Bootstrap, MaterialUI, Nest.js, Fastify, Express, AWS, Bitbucket, Git, Jenkins, PostgreSQL, Docker, REST, GraphQL, SQL, NoSQL, Strapi 🏢 Description: About the Webellian Webellian is a well-established Digital Transformation and IT consulting company committed to creating a positive impact for our clients. We strive to make a meaningful difference in diverse sectors such as insurance, banking, healthcare, retail, and manufacturing. Our passion for cutting-edge and disruptive technologies, as well as our shared values and strong principles, are what motivate us. We are a community of engineers and senior advisors who work with our clients across industries, playing a deep and meaningful role in accelerating and realizing their vision and strategy. About the opportunity We are seeking an experienced Senior Fullstack Engineer (Node.js & React) to join our team and work on exciting projects for our key customers. In this role, you will have the opportunity to interface with our clients and drive the development of their solutions. For instance, you will join the team working on a back-office solution for a global insurance industry leader using Strapi and React. As a software engineer, you will be responsible for delivering high-quality projects by defining technical requirements based on business needs and deploying clean code. You won't need to reinvent the wheel as we value the power of reusing open-source frameworks and solutions. To be successful in this position, you must have at least 5 years of experience in Fullstack development, a deep understanding of Node.js, React and related frameworks , and experience in working collaboratively in a team environment. Join our team, work with us on challenging projects! Key responsibilities Analyzing business requirements Writing clean, functional code, including unit tests Writing technical documentation Propose technical improvements to the application Grow and nurture your junior colleagues' skills Supporting less experienced team members Competencies Master’s degree in Software Engineering or related engineering field Frontend Technologies: React, React Native, Next.js, Redux, Typescript, Bootstrap, Material UI Backend Technologies: Node.js, Nest.js, Fastify, Express Other Technologies: AWS, Bitbucket/GIT, Jenkins, PostgreSQL, Docker Familiarity with REST API and GraphQL Familiarity with SQL, NoSQL databases Deep understanding of software architecture and development principles Fluency in English is a must (min B2, C1 preferred) Excellent verbal communication skills are a must Can-do attitude Great attention to detail Independence and drive to grow and learn What we offer Contract under Polish law: B2B or Umowa o Pracę Benefits such as private medical care, group insurance, Multisport card There are English classes available Hybrid work (at least 3 days/week on-site) in Warsaw (Mokotów) Opportunity to work with excellent professionals High standards of work and focus on the quality of code New technologies in use Continuously learning and growth International team Pinball, PlayStation & much more (on-site 🤫) Join a growing team of dedicated professionals! We love to pass on the knowledge to grow excellence, speak our minds without playing politics, and just enjoy hanging around together. If you share our passions - we want to meet you! So go ahead and apply ➡️ Please include the following statement: I hereby authorize Webellian Poland Sp. z o.o. to the process personal data provided in this document for realising the recruitment process pursuant to the Personal Data Protection Act of 10 May 2018 (Journal of Laws 2018, item 1000) and in agreement with Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016 on the protection of natural persons with regard to the processing of personal data and on the free movement of such data, and repealing Directive 95/46/EC (General Data Protection Regulation).

🏢 Summary: Fullstack Engineer role focused on developing back-office and client solutions using Node.js and React technologies in a collaborative international environment. The position involves analyzing business requirements, building scalable applications, writing clean code and technical documentation, and supporting junior team members. Hybrid work in Warsaw with opportunities to work on modern technologies and enterprise projects. 🗂️ Requirements: 3+ years of Fullstack development experience, Master’s degree in Software Engineering or related field, Strong knowledge of Node.js and React, Experience with related frontend and backend frameworks, Familiarity with REST API and GraphQL, Knowledge of SQL and NoSQL databases, Understanding of software architecture and development principles, Fluent English level B2 minimum, Excellent verbal communication skills 📃 Skills: Node.js, React, ReactNative, Next.js, Redux, TypeScript, Bootstrap, MaterialUI, Nest.js, Fastify, Express, AWS, Bitbucket, Git, Jenkins, PostgreSQL, Docker, REST, GraphQL, SQL, NoSQL, Strapi 🏢 Description: About the Webellian Webellian is a well-established Digital Transformation and IT consulting company committed to creating a positive impact for our clients. We strive to make a meaningful difference in diverse sectors such as insurance, banking, healthcare, retail, and manufacturing. Our passion for cutting-edge and disruptive technologies, as well as our shared values and strong principles, are what motivate us. We are a community of engineers and senior advisors who work with our clients across industries, playing a deep and meaningful role in accelerating and realizing their vision and strategy. About the opportunity We are seeking an experienced Fullstack Engineer (Node.js & React) to join our team and work on exciting projects for our key customers. In this role, you will have the opportunity to interface with our clients and drive the development of their solutions. For instance, you will join the team working on a back-office solution for a global insurance industry leader using Strapi and React. As a software engineer, you will be responsible for delivering high-quality projects by defining technical requirements based on business needs and deploying clean code. You won't need to reinvent the wheel as we value the power of reusing open-source frameworks and solutions. To be successful in this position, you must have at least 3 years of experience in Fullstack development, a deep understanding of Node.js, React and related frameworks , and experience in working collaboratively in a team environment. Join our team, work with us on challenging projects! Key responsibilities Analyzing business requirements Writing clean, functional code, including unit tests Writing technical documentation Propose technical improvements to the application Grow and nurture your junior colleagues' skills Supporting less experienced team members Competencies Master’s degree in Software Engineering or related engineering field Frontend Technologies: React, React Native, Next.js, Redux, Typescript, Bootstrap, Material UI Backend Technologies: Node.js, Nest.js, Fastify, Express Other Technologies: AWS, Bitbucket/GIT, Jenkins, PostgreSQL, Docker Familiarity with REST API and GraphQL Familiarity with SQL, NoSQL databases Deep understanding of software architecture and development principles Fluency in English is a must (min B2, C1 preferred) Excellent verbal communication skills are a must Can-do attitude Great attention to detail Independence and drive to grow and learn What we offer Contract under Polish law: B2B or Umowa o Pracę Benefits such as private medical care, group insurance, Multisport card There are English classes available Hybrid work (at least 3 days/week on-site) in Warsaw (Mokotów) Opportunity to work with excellent professionals High standards of work and focus on the quality of code New technologies in use Continuously learning and growth International team Pinball, PlayStation & much more (on-site 🤫) Join a growing team of dedicated professionals! We love to pass on the knowledge to grow excellence, speak our minds without playing politics, and just enjoy hanging around together. If you share our passions - we want to meet you! So go ahead and apply ➡️ Please include the following statement: I hereby authorize Webellian Poland Sp. z o.o. to the process personal data provided in this document for realising the recruitment process pursuant to the Personal Data Protection Act of 10 May 2018 (Journal of Laws 2018, item 1000) and in agreement with Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016 on the protection of natural persons with regard to the processing of personal data and on the free movement of such data, and repealing Directive 95/46/EC (General Data Protection Regulation).

🏢 Summary: 6-month Full Stack Engineer internship focused on building and supporting web applications using Node.js and React. The role involves collaborating with the engineering team across the full development lifecycle, from conception to delivery, contributing to clean code, testing, and technical documentation. 🗂️ Requirements: Enrolled in Bachelor’s or Master’s degree in Computer Science or related technical field, Familiarity with JavaScript, Familiarity with TypeScript, Familiarity with Node.js, Familiarity with React, Familiarity with REST API, Familiarity with GraphQL, Familiarity with SQL databases, Familiarity with NoSQL databases, Familiarity with AWS, Familiarity with Git or Bitbucket, Familiarity with Jenkins, Familiarity with PostgreSQL, Familiarity with Docker 📃 Skills: JavaScript, TypeScript, Node.js, React, REST, GraphQL, SQL, NoSQL, AWS, Git, Bitbucket, Jenkins, PostgreSQL, Docker 🏢 Description: About Webellian Webellian is a well-established Digital transformation and IT consulting company committed to creating a positive impact for our clients. We are driven by shared values, strong principles, and a passion for innovative and disruptive technologies. We are a community of engineers and senior advisors who work with our clients across industries, playing a deep and meaningful role in accelerating and realizing their vision and strategy. About the job We are actively looking for an intern Full Stack Engineer (Node.js & React). As an intern Full Stack Engineer you will collaborate with the engineering team, you will have the opportunity to help them from conception to delivery, on the ongoing projects. Requirements Being enrolled in a Bachelor’s or Master’s degree in Computer Science or a related technical field. Familiarity with: JavaScript, TypeScript, Node.js Familiarity with : React, React Native will be considered as a plus Familiarity with REST API and GraphQL Familiarity with SQL, NoSQL databases Good English skills (B2+), Polish is a plus Excellent verbal communication skills. Familiarity with other technologies: AWS, Bitbucket/GIT, Jenkins, PostgreSQL, Docker A grasp of software architecture trade-offs and considerations, an understanding of software development principles such as design patterns and SOLID concepts (Nice to have) Key responsibilities Help to write clean, functional code, including unit tests Help to write technical documentation Participate in troubleshooting and resolving technical issues Collaborate with the engineering team from conception to delivery What we offer 6 month internship Opportunity to work with excellent professionals, in a professional and friendly environment High standards of work and focus on the quality of code New technologies in use Continuously learning and growth International team Pinball, PlayStation & much more (on-site) About you: Open-minded and eager to learn Autonomous and not afraid to ask questions Business oriented and looking to bring solutions Capable of detailed and analytical thinking Ready to take responsibilities and have an impact on companies’ projects BE BOLD In your CV, please include the following information: Why would you like to join us? Do you have something to share with us? (portfolio, projects, ideas, …)

🏢 Summary: Full Stack Engineer role focused on building scalable distributed applications using Java and modern frontend technologies in an agile environment. The position involves backend and frontend development, microservices, testing, and collaboration with cross-functional teams in a hybrid work model in Warsaw. 🗂️ Requirements: Proven experience as a Full Stack Engineer, Strong experience with Java, Strong experience with Spring, Strong experience with Kafka, Strong understanding of TypeScript, Strong understanding of Angular, Experience with databases, Experience with distributed systems, Solid understanding of microservice architecture, Experience writing unit tests, Experience writing integration tests, Ability to work in agile delivery environments, Strong communication skills 📃 Skills: Java, Spring, Kafka, TypeScript, Angular, SQL, Microservices, Docker, Kubernetes, OpenAPI, Swagger, Atlas, DevOps, AI, MachineLearning 🏢 Description: About Webellian Webellian is a well-established Digital Transformation and IT consulting company committed to creating a positive impact for our clients. We strive to make a meaningful difference in diverse sectors such as insurance, banking, healthcare, retail, and manufacturing. Our passion for cutting-edge and disruptive technologies, as well as our shared values and strong principles, are what motivate us. We are a community of engineers and senior advisors who work with our clients across industries, playing a deep and meaningful role in accelerating and realizing their vision and strategy. About the position We are seeking a motivated and experienced Full Stack Engineer with a strong background in Java and distributed systems to join our dynamic team. The ideal candidates will have extensive expertise in developing scalable and maintainable applications in agile-based delivery environments, with a proactive approach to problem-solving. Key responsibilities: Design, develop, and maintain applications in a complex and interconnected environment. Participate in code reviews and contribute to a culture of continuous improvement. Analyze existing business logic and data structures across several systems. Collaborate with cross-functional teams to refine, design, and develop new features. Troubleshoot and resolve complex technical issues. Required Experience & Skills Proven experience as a Full Stack Engineer Ability to learn quickly and adapt to new technologies and methodologies. Strong communication skills. Strong experience with backend technologies (Java, Spring, Kafka). Strong understanding of front-end technologies (TypeScript, Angular). Experience with databases and distributed systems. Solid understanding of microservice architecture. Strong testing background and experience writing unit- and integration tests. Preferred Qualifications Familiarity with containerization and orchestration tools (e.g., Docker, Kubernetes). DevOps experience. Knowledge of Atlas or similar database migration tools. Familiarity with OpenAPI/Swagger specifications and code generation. Knowledge of AI and machine learning concepts. What we offer Contract under Polish law: B2B or Umowa o Pracę Benefits such as private medical care, group insurance, Multisport card There are English classes available Hybrid work (at least 1 day/week on-site) in Warsaw (Mokotów) Opportunity to work with excellent professionals High standards of work and focus on the quality of code New technologies in use Continuously learning and growth International team Pinball, PlayStation & much more (on-site) Join a growing team of dedicated professionals! We love to pass on the knowledge to grow excellence, speak our minds without playing politics, and just enjoy hanging around together. If you share our passions - we want to meet you! So go ahead and apply ➡️

🏢 Summary: Senior Full Stack Developer role focused on architecting and delivering high-performance web applications using React and Node.js. The position involves leading system design, building scalable front-end and back-end solutions, and overseeing cloud-based deployments and DevOps processes. The role includes technical ownership of microservices, APIs, databases, and application performance in a hybrid Warsaw-based setup. 🗂️ Requirements: 7+ years full stack development experience, 2+ years in senior or technical lead role, Expert-level React.js with Hooks and Redux, Advanced JavaScript ES6+ proficiency, Strong Node.js and Express.js experience, Experience designing REST or GraphQL APIs, Experience with OAuth, JWT, sessions, RBAC, Database design and optimization with PostgreSQL, MySQL, or MongoDB, Hands-on Docker experience, Experience with AWS, Azure, or GCP, CI/CD pipeline management experience, Proficiency with Git workflows, Bachelor’s or Master’s in Computer Science or related field 📃 Skills: React, Redux, JavaScript, HTML5, CSS3, Node.js, Express, GraphQL, REST, OAuth, JWT, RBAC, PostgreSQL, MySQL, MongoDB, Docker, Kubernetes, AWS, Azure, GCP, Git, CI/CD, Webpack, Babel, Vite 🏢 Description: 🧩 About the Company Our client is a rapidly growing US-based technology firm with global operations. With a strong commitment to innovation and quality engineering, the company is building a new engineering hub in Warsaw. This is your opportunity to join a high-performing team and play a pivotal role in developing next-generation digital solutions for the private capital markets. 📍 Location & Setup Start remotely and transition to a hybrid model based in Warsaw (3 days/week in the office in the coming months). 🧠 The Role: Senior Full Stack Developer (React & Node.js) We’re looking for an expert-level Senior Full Stack Developer with at least 7 years of professional experience in designing, architecting, and delivering high-performance web applications. You will take ownership of complex technical challenges across both the front-end and back-end, drive architectural decisions, and provide technical leadership and mentorship within the software development lifecycle. 🔧 Key Responsibilities Technical Leadership: Architect and develop scalable, responsive UIs with React.js, Redux, and modern JavaScript (ES6+). System Design: Design, build, and scale advanced server-side applications, microservices architecture, and RESTful/GraphQL APIs with Node.js and Express. Data Architecture: Lead database design, optimization, and integration strategies (PostgreSQL, MySQL, or MongoDB). Quality Assurance: Define testing strategies, write robust unit/integration tests, and establish efficient debugging protocols for the team. DevOps & Deployment: Oversee and optimize CI/CD pipelines, containerization using Docker, and cloud deployments. Agile Mentorship: Lead agile collaboration with product managers, designers, and engineers, while mentoring mid-level and junior developers. Performance: Proactively monitor system performance, identify bottlenecks, and maintain high-availability production-grade applications. Standards: Establish and maintain comprehensive technical documentation and coding standards. 📌 What We’re Looking For Front-End: Expert-level experience with React.js, Hooks, Redux, and complex component-based architecture. Deep mastery of HTML5, CSS3, and ES6+. Advanced configuration and optimization experience with build tools like Webpack, Babel, or Vite. Back-End: Senior-level proficiency in Node.js & Express.js for enterprise applications. Extensive API design and architecture experience (GraphQL highly preferred, alongside REST). Deep understanding and implementation experience with advanced security and authentication protocols: OAuth, JWT, sessions, and RBAC. Databases & DevOps: Proven experience in scaling and optimizing relational and non-relational databases (PostgreSQL, MySQL, or MongoDB). Solid hands-on experience with Docker; Kubernetes experience is highly advantageous. Demonstrated experience designing and deploying applications on cloud platforms (AWS, Azure, or GCP). Advanced proficiency with Git workflows and driving Agile/Scrum methodologies. 🎓 Qualifications Bachelor’s or Master’s in Computer Science or a related field. 7+ years of hands-on experience in full stack development. 2+ years of experience in a senior or technical lead capacity. Proven track record of architecting, deploying, and maintaining high-traffic production applications. 💡 Soft Skills Strategic, analytical thinker and highly effective problem-solver. Strong technical leadership, team collaboration, and cross-functional communication skills. Self-motivated with excellent time management and the ability to drive projects autonomously. Passion for continuous learning, adopting new technologies, and sharing knowledge with the team. 🎁 What’s Offered Competitive salary up to $6,200 USD/month. Hybrid remote role with 3 days form office in the heart of Warsaw Generous Paid Time Off (PTO). Comprehensive full benefits package. The unique chance to shape the technical foundation of a new engineering hub and lead high-impact projects. A supportive, innovation-driven work environment that values technical excellence.

🏢 Summary: Senior AI/Full Stack Engineer role focused on building AI-powered applications using LLMs, RAG systems, and modern full-stack technologies. The position involves developing and deploying intelligent systems, integrating AI with external services, and making architectural decisions in a collaborative environment. The offer includes work with cutting-edge AI tooling, local GPU infrastructure, and high ownership over technical decisions. 🗂️ Requirements: 5+ years of full-stack development experience, TypeScript, Node.js, Nest.js, React, Experience with LLM deployment and serving, Experience building RAG systems, Understanding of prompt engineering, Understanding of agent/tool-use patterns, Experience with relational databases, Redis, Docker, Basic CI/CD knowledge, Ability to evaluate model performance, English B2+, Strong problem-solving skills 📃 Skills: AI, ML, LLMs, RAG, TypeScript, Node.js, Nest.js, React, PostgreSQL, Redis, Docker, CI/CD, Embeddings, LangChain, AWS, LoRA, QLoRA, MLOps, GPU 🏢 Description: About Webellian Webellian is a well-established Digital Transformation and IT consulting company committed to creating a positive impact for our clients. We strive to make a meaningful difference in diverse sectors such as insurance, banking, healthcare, retail, and manufacturing. Our passion for cutting-edge and disruptive technologies, as well as our shared values and strong principles, are what motivate us. We are a community of engineers and senior advisors who work with our clients across industries, playing a deep and meaningful role in accelerating and realizing their vision and strategy. About the role We are seeking a Senior AI/Full Stack Engineer to join our team and drive the development of AI-powered solutions for our clients. You will work on projects that combine modern web development with applied AI - from building intelligent agents and search systems to deploying and optimizing language models on dedicated infrastructure. This role bridges two worlds: solid full-stack engineering and practical AI/ML implementation. You'll design, build, and ship products that leverage LLMs, RAG, and other AI techniques to solve real business problems. Your responsibilities Designing and developing full-stack applications with AI capabilities Deploying, configuring, and optimizing LLMs (both cloud APIs and self-hosted) Building and maintaining RAG pipelines, vector search, and knowledge retrieval systems Integrating AI systems with external services and APIs Evaluating and selecting appropriate models and tools for specific use cases Writing clean, maintainable code with tests and documentation Proposing technical improvements and architectural decisions Supporting and mentoring less experienced team members Must-have requirements AI/ML: Hands-on experience with LLM deployment and serving (cloud APIs and/or self-hosted solutions) Experience building RAG systems (embeddings, vector stores, retrieval strategies) Understanding of prompt engineering and agent/tool-use patterns Ability to evaluate model performance and make informed trade-off decisions Full Stack: 5+ years in full-stack development with TypeScript/Node.js, Nest.js Frontend experience with React Relational databases (PostgreSQL or similar), Redis Docker, basic CI/CD Soft skills: Self-driven, able to take ownership of projects end-to-end Strong problem-solving skills English B2+ (C1 preferred) Excellent communication - able to translate technical concepts for non-technical stakeholders Nice-to-have Experience with model fine-tuning (LoRA, QLoRA) MLOps practices (experiment tracking, model versioning) Familiarity with agent frameworks (LangChain, Vercel AI SDK, or similar) React Native and knowledge of mobile development Experience with GPU infrastructure and model optimization (quantization, inference tuning) AWS or other cloud provider (working knowledge) What we offer Projects at the intersection of AI and software engineering Opportunity to work with cutting-edge AI tooling and local GPU infrastructure Autonomy and ownership over technical decisions Hybrid work mode Small, collaborative team Challenging problems - no boring CRUD work

🏢 Summary: Senior AI/Full Stack Engineer role focused on building and delivering AI-powered web applications that integrate LLMs, RAG pipelines, and modern full-stack technologies. The position combines hands-on AI/ML implementation with TypeScript-based backend and React frontend development. You will design, deploy, and optimize intelligent systems running on cloud and self-hosted infrastructure. 🗂️ Requirements: 5+ years of full-stack development experience, Hands-on experience with LLM deployment and serving (cloud APIs or self-hosted), Experience building RAG systems including embeddings and vector stores, Understanding of prompt engineering and agent/tool-use patterns, Ability to evaluate model performance and make trade-off decisions, Strong experience with TypeScript and Node.js, Experience with Nest.js, Frontend development experience with React, Experience with relational databases such as PostgreSQL, Experience working with Redis, Experience using Docker, Basic knowledge of CI/CD pipelines 📃 Skills: TypeScript, Node.js, Nest.js, React, PostgreSQL, Redis, Docker, CI/CD, LLM, RAG, Embeddings, VectorDB, APIs 🏢 Description: About Webellian Webellian is a well-established Digital Transformation and IT consulting company committed to creating a positive impact for our clients. We strive to make a meaningful difference in diverse sectors such as insurance, banking, healthcare, retail, and manufacturing. Our passion for cutting-edge and disruptive technologies, as well as our shared values and strong principles, are what motivate us. We are a community of engineers and senior advisors who work with our clients across industries, playing a deep and meaningful role in accelerating and realizing their vision and strategy. About the role We are seeking a Senior AI/Full Stack Engineer to join our team and drive the development of AI-powered solutions for our clients. You will work on projects that combine modern web development with applied AI - from building intelligent agents and search systems to deploying and optimizing language models on dedicated infrastructure. This role bridges two worlds: solid full-stack engineering and practical AI/ML implementation. You'll design, build, and ship products that leverage LLMs, RAG, and other AI techniques to solve real business problems. Your responsibilities Designing and developing full-stack applications with AI capabilities Deploying, configuring, and optimizing LLMs (both cloud APIs and self-hosted) Building and maintaining RAG pipelines, vector search, and knowledge retrieval systems Integrating AI systems with external services and APIs Evaluating and selecting appropriate models and tools for specific use cases Writing clean, maintainable code with tests and documentation Proposing technical improvements and architectural decisions Supporting and mentoring less experienced team members Must-have requirements AI/ML: Hands-on experience with LLM deployment and serving (cloud APIs and/or self-hosted solutions) Experience building RAG systems (embeddings, vector stores, retrieval strategies) Understanding of prompt engineering and agent/tool-use patterns Ability to evaluate model performance and make informed trade-off decisions Full Stack: 5+ years in full-stack development with TypeScript/Node.js, Nest.js Frontend experience with React Relational databases (PostgreSQL or similar), Redis Docker, basic CI/CD Soft skills: Self-driven, able to take ownership of projects end-to-end Strong problem-solving skills English B2+ (C1 preferred) Excellent communication - able to translate technical concepts for non-technical stakeholders Nice-to-have Experience with model fine-tuning (LoRA, QLoRA) MLOps practices (experiment tracking, model versioning) Familiarity with agent frameworks (LangChain, Vercel AI SDK, or similar) Experience with GPU infrastructure and model optimization (quantization, inference tuning) AWS or other cloud provider (working knowledge) What we offer Projects at the intersection of AI and software engineering Opportunity to work with cutting-edge AI tooling and local GPU infrastructure Autonomy and ownership over technical decisions Hybrid work mode Small, collaborative team Challenging problems - no boring CRUD work

🏢 Summary: Senior Fullstack Engineer role focused on building scalable enterprise applications using .NET and React in a hybrid Krakow-based environment. The position involves full software lifecycle ownership, UI improvements, DevOps automation, architecture contributions, and customer-facing solution delivery. 🗂️ Requirements: 7+ years of experience in .NET application development, Experience with React frontend development, Proficiency in C#, Experience with Web API development, Advanced SQL Server and T-SQL skills, Understanding of SDLC processes, Experience with DevOps practices, Fluent English, Legal right to work in the European Union 📃 Skills: .NET, React, C#, WebAPI, SQL, SQLServer, TSQL, DevOps, SDLC, Docker, Kubernetes 🏢 Description: Unleash innovation — shape the future of enterprise applications. Krakow-based opportunity with hybrid work model. As a Senior Fullstack Engineer – .NET and React Development , you will be working for our client, a leader in enterprise software solutions, dedicated to delivering robust, scalable, and innovative digital tools. Your expertise will drive the development of cutting-edge applications that empower businesses worldwide, supporting their digital transformation journeys. Your main responsibilities: Implement solutions following best Design Patterns to ensure maintainability and scalability Analyze requirements to fully understand solutions and recommend improvements for optimal performance Lead UI enhancements and improvements to boost user experience and application stability Actively participate in DevOps automation and improve the CI/CD lifecycle processes Manage changes through the entire service management lifecycle, ensuring seamless updates Contribute to software architecture design and technical decision-making Develop and prototype applications to validate concepts and designs Provide exceptional customer support by addressing and resolving issues promptly Communicate effectively with clients to understand needs and deliver tailored solutions You're ideal for this role if you have: A minimum of 7 years of professional experience in production application development within .NET ecosystems, including front-end (preferably React) and DevOps practices Proficiency in C# and Web API development, with a focus on scalable, secure backend services Strong hands-on experience with React, building dynamic, responsive web applications Advanced SQL skills, particularly with SQL Server, including T-SQL scripting, query optimization, and performance tuning Solid understanding of the SDLC, from requirement gathering to deployment and maintenance Exceptional problem-solving abilities and an eye for detail to ensure high-quality deliverables It is a strong plus if you have: (optional) Certifications in cloud or DevOps tools Experience with containerization (e.g., Docker, Kubernetes) Language Required for the role: Fluent English (written and spoken) Eligibility for the role: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Fullstack Engineer role focused on developing scalable enterprise applications using .NET and React in a hybrid Krakow-based environment. The position involves full lifecycle development, UI enhancements, DevOps automation, architecture contributions, and customer-focused solution delivery. 🗂️ Requirements: 7+ years of experience in .NET application development, Experience with React frontend development, Proficiency in C#, Experience with Web API development, Advanced SQL Server and T-SQL skills, Understanding of SDLC processes, Experience with DevOps practices, Fluent English, Legal right to work in the European Union 📃 Skills: .NET, React, C#, WebAPI, SQL, SQLServer, T-SQL, DevOps, CI/CD, Docker, Kubernetes 🏢 Description: Unleash innovation — shape the future of enterprise applications. Krakow-based opportunity with hybrid work model. As a Senior Fullstack Engineer – .NET and React Development , you will be working for our client, a leader in enterprise software solutions, dedicated to delivering robust, scalable, and innovative digital tools. Your expertise will drive the development of cutting-edge applications that empower businesses worldwide, supporting their digital transformation journeys. Your main responsibilities: Implement solutions following best Design Patterns to ensure maintainability and scalability Analyze requirements to fully understand solutions and recommend improvements for optimal performance Lead UI enhancements and improvements to boost user experience and application stability Actively participate in DevOps automation and improve the CI/CD lifecycle processes Manage changes through the entire service management lifecycle, ensuring seamless updates Contribute to software architecture design and technical decision-making Develop and prototype applications to validate concepts and designs Provide exceptional customer support by addressing and resolving issues promptly Communicate effectively with clients to understand needs and deliver tailored solutions You're ideal for this role if you have: A minimum of 7 years of professional experience in production application development within .NET ecosystems, including front-end (preferably React) and DevOps practices Proficiency in C# and Web API development, with a focus on scalable, secure backend services Strong hands-on experience with React, building dynamic, responsive web applications Advanced SQL skills, particularly with SQL Server, including T-SQL scripting, query optimization, and performance tuning Solid understanding of the SDLC, from requirement gathering to deployment and maintenance Exceptional problem-solving abilities and an eye for detail to ensure high-quality deliverables It is a strong plus if you have: (optional) Certifications in cloud or DevOps tools Experience with containerization (e.g., Docker, Kubernetes) Language Required for the role: Fluent English (written and spoken) Eligibility for the role: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.