Paychex is reimagining how organizations manage their workforce by unifying payroll, HR, benefits, and advisory services into a single connected HCM platform. As Paychex and Paycor integrate, we are combining innovative technology, data-driven insights, AI, and human expertise to help organizations work smarter, support their people, and achieve better business outcomes. This is an exciting time to join our team as One Paychex. We are seeking a Senior Full-Stack Engineer with a React focus to join our Belgrade, Serbia team. Responsibilities include building and leading frontend architecture using React, MUI, and high-fidelity design integrations; owning full-stack feature delivery with Python on AWS serverless (Lambda) and clean GraphQL API integration; collaborating with Product and Design to define roadmaps; architecting and integrating GraphQL APIs to power dynamic content; contributing to AI-powered features and intelligent automation interfaces; mentoring junior engineers and promoting clean code and BDD/TDD practices; integrating with our CI/CD pipelines; helping shape our design system and a scalable UI foundation. Qualifications include 5+ years of full-stack development with React and Python/AWS serverless; deep knowledge of React and MUI; experience with GraphQL and API-driven frontends; background in AI-powered features and intelligent UI flows; strong testing and clean coding mindset (BDD, TDD, SOLID); DevOps-aware mindset (CI/CD with CircleCI and GitHub Actions, observability, rollback readiness); experience leading product delivery and planning; experience bui

Paychex is reimagining how organizations manage their workforce by unifying payroll, HR, benefits, and advisory services into a single connected HCM platform. As Paychex and Paycor integrate, we are combining innovative technology, data-driven insights, AI, and human expertise to help organizations work smarter, support their people, and achieve better business outcomes. This is an exciting time to join our team as One Paychex. We are seeking a Senior Full-Stack Engineer with a React focus to join our Belgrade, Serbia team. Responsibilities include building and leading frontend architecture using React, MUI, and high-fidelity design integrations; owning full-stack feature delivery with Python on AWS serverless (Lambda) and clean GraphQL API integration; collaborating with Product and Design to define roadmaps; architecting and integrating GraphQL APIs to power dynamic content; contributing to AI-powered features and intelligent automation interfaces; mentoring junior engineers and promoting clean code and BDD/TDD practices; integrating with our CI/CD pipelines; helping shape our design system and a scalable UI foundation. Qualifications include 5+ years of full-stack development with React and Python/AWS serverless; deep knowledge of React and MUI; experience with GraphQL and API-driven frontends; background in AI-powered features and intelligent UI flows; strong testing and clean coding mindset (BDD, TDD, SOLID); DevOps-aware mindset (CI/CD with CircleCI and GitHub Actions, observability, rollback readiness); experience leading product delivery and planning; experience bui