Can a PWA be built on top of an existing store?
A PWA service (Progressive Web App), like most apps, runs on top of communication with a backend. The app itself is responsible for the visual layer (the interface — UI) and marketing functions, while all the logic, product information, and order processing stays on the operational backend.
So to build a PWA on top of an existing store we have to make sure that the current platform can be the backend that provides the right data and communication channel (e.g. the popular REST API).
Most open-source platforms or dedicated platforms where we have access to the source code can be adjusted accordingly to the PWA requirements. Closed apps — e.g. popular SaaS platforms — that don't expose a full API by default cannot be adapted.
Mature open-source platforms such as Magento 2 ship APIs that allow building apps on top of them. This typically requires some additional backend work, but much less than building the entire backend from scratch. On top of that, both for Magento and for other platforms, you can find ready-made frameworks based on PWA. One of them is Vue Storefront. As PWA gains traction, official tools are appearing too — for example PWA Studio from Adobe (a Magento-targeted solution).
Most open-source platforms or dedicated platforms where we have access to the source code can be adjusted accordingly to the PWA requirements. Closed apps — e.g. popular SaaS platforms — that don't expose a full API by default cannot be adapted.
Mature open-source platforms such as Magento 2 ship APIs that allow building apps on top of them. This typically requires some additional backend work, but much less than building the entire backend from scratch. On top of that, both for Magento and for other platforms, you can find ready-made frameworks based on PWA. One of them is Vue Storefront. As PWA gains traction, official tools are appearing too — for example PWA Studio from Adobe (a Magento-targeted solution).