Answer
What are some well-known examples of PWAs?
Well-documented production PWAs include Twitter Lite (X’s lightweight PWA for low-bandwidth markets), the Starbucks ordering PWA (built for reliable performance on slow connections), Pinterest’s mobile web PWA, and Uber’s m.uber.com PWA designed to work on low-end feature phones. Each company has published its own case study describing the goals and outcomes of its build.
Twitter Lite
Built specifically to serve markets with expensive data and slow networks, using aggressive caching and a small bundle size.
Starbucks
Rebuilt its ordering site as a PWA to work reliably even on slow connections, given that many customers order from inside stores with poor signal.
Where to read the details
web.dev hosts a library of company-submitted PWA case studies with the specific goals and techniques each team used.