I will present my recent work 1902.10093 on classical de Sitter string backgrounds, motivated by the connection of string theory to cosmology, with a revived interest in the context of the swampland program. I will also say a word on the recent works 1812.04147, by C.Cordova, G.B.De Luca, A.Tomasiello, and 1902.08209, by N.Cribiori, D.Junghans.