A non-exhaustive list of the tools I use:
User Interface
React, Preact, Svelte, TailwindCSS, Bootstrap, JQuery
Back-end Frameworks
NodeJS, Symfony
Databases
MySQL, MongoDB, CouchDB, PouchDB
Web servers
Nginx, ExpressJS, Caddy
Web hosting
Hetzner, Netlify, Vercel
Static site generators
GatsbyJS, NextJS
Progressive web apps
Service Worker API, Workbox
CI/CD
Github Actions, Git, Webpack, Snowpack, Rollup
Libraries
Prosemirror, DraftJS, Slate, yjs
APIs
Stripe, Amazon Simple Email Service Slack, Twitter, Trello, IBM Watson