Q2 2019 EU : Whats the best mobile + web + payment + checkout experience ?

Q2 2019 EU : Whats the best mobile + web + payment + checkout experience ?

Hey there, we are looking for inspiration regarding mobile + web + payment + checkout experience for amounts ~ 2-30 €.

I wish to experience smooth and frictionless as possible

I know that Payment request API is W3C OK so better things are coming but I would go with PayPal + G/Apple Pay and credit card

For now the best example I have is thetrainline.com , those guys rocks in UI/UX

Any recommendations to look for ?

Cheers !