● Collaborated with front-end developers and stakeholders to gather requirements and translate them into technical specifications, ensuring alignment with project goals.● Constructed and maintained 15 RESTful APIs and microservices to facilitate seamless communication between front-end and back-end systems, ensuring data integrity and security.● Applied asynchronous programming and multithreading concepts, optimising system performance and responsiveness, resulting in a 30% reduction in response time.● Conducted testing and debugging, identifying and resolving bugs and issues, resulting in improved application reliability and stability.● Monitored and analysed application performance, identifying and resolving 8 bottlenecks and issues, resulting in improved application responsiveness and user satisfaction.● Networked with database administrators to design and optimise database schemas and queries, resulting in a 20% improvement in database performance.● Led the development of web applications using ReactJS, Node.js, MongoDB resulting in a 25% improvement in user interface responsiveness and a 15% increase in user engagement.● Established advanced user authentication and authorization systems with Auth0, fortified by JSON Web Token encryption, guaranteeing ironclad security and enabling seamless access to critical application resources.