Tic Tac Toe на Svelte, серия статей Владимира Номхоева: от сравнения Svelte и React до работы с бэкендом:

https://habr.com/p/456474/
https://habr.com/p/458752/
https://habr.com/p/459630/
https://habr.com/p/459906/
https://habr.com/p/460621/
https://habr.com/p/460991/
https://habr.com/p/461531/