Highly experienced, senior-level, full-stack Node.js and React.js focused engineer needed

We have an existing, highly scaled web app and our team is looking for some help working on some new features. We are looking for a senior-level, full-stack engineer (5+ years experience) with proven expertise in React.js and Node.js. You must have experience with Webpack, Express/Koa, ES6/TypeScript, SCSS and Git/GitHub. You must right clean, testable code (your code will be reviewed and approved by our existing team). You will have to complete an interview (and possibly a take-home-style code test).