ReactJS Developer Profile:

As a ReactJS developer, I am highly proficient in JavaScript and have extensive experience building user interfaces for web applications using the ReactJS library. 

I am skilled in developing reusable and scalable components, integrating APIs and other external services, and utilizing front-end development tools such as Webpack, Babel, and Redux. 

I am also experienced in testing frameworks such as Jest and Enzyme to ensure high-quality code. With strong communication and collaboration skills, I am able to work effectively with other developers, designers, and stakeholders to deliver successful projects.

MERN Stack Developer Profile:

As a MERN stack developer, I have a strong understanding of JavaScript and proficiency in each component of the MERN stack, including MongoDB, ExpressJS, ReactJS, and NodeJS. 

I am skilled in designing and developing APIs, integrating external services, and implementing database schemas and models using MongoDB. 

Additionally, I have experience with front-end development concepts such as JSX, virtual DOM, and state management, and have worked with front-end development tools such as Webpack, Babel, and Redux. With excellent communication and collaboration skills, I am able to work effectively with other developers, designers, and stakeholders to deliver successful full-stack web applications.