The Modest Web Store was a mobile-first, responsive, multi-tenant web application that powered each of our merchant's web-based storefronts. In addition to (and more importantly than) a browsable store, it powered contextual buy buttons and instant checkout screens that could be embedded into ads, emails, and anywhere else on the web or in a mobile application. The client-side of the web store was initially built in Backbone.js and integrated with the Modest Commerce API via a thin Node.js proxy. Later, we started to migrate the front-end to Vue.js. I was the architect, tech lead, and leading contributor to the web client.