Senior Fullstack Developer (React / Node.js) – Fully Remote

Experis is a global leader in recruitment of IT specialists and management staff in key IT areas. It offers competitive employment opportunities and interesting IT projects for both experienced experts and newcomers to the IT industry. Experis is part of ManpowerGroup and has been recognized as one of the most ethical companies in the world.

• Minimum 5 years of professional experience as a Fullstack Developer
• Very strong knowledge of React and TypeScript
• Solid experience with Node.js and API development
• Hands-on experience with webhooks and system integrations
• Ability to read, understand, and extend existing backend codebases
• Practical experience using Claude Code or similar AI-assisted coding tools
• English proficiency at C1 level (daily collaboration with international clients)
• Polish proficiency at B2 level or higher (internal team communication)

• Design and develop a new custom module within an existing HubSpot application
• Build user-facing interfaces for internal HubSpot users
• Implement a management panel for customer trials and licenses
• Integrate the application with existing internal APIs
• Identify and implement missing backend functionalities
• Develop integration code in Node.js connecting LMS webhooks with the authentication system
• Automate user account creation based on LMS-triggered events
• Automate user roles and permissions assignment based on learning system data
• Ensure data consistency, reliability, and observability across systems
• Handle error management, retries, and monitoring of webhook-based flows