Tensai Renkinjutsushi wa Kimama ni Tabisuru: 500-nengo no Sekai de Mezameta Sekai Saikou no Moto Kyuutei Renkinjutsushi, Potion-zukuri de Seijo-sama Atsukai sareru

The youngest girl ever to become a court alchemist, Seyi, was busy with hard work every day. One day, the royal city was suddenly attacked by a horde of monsters, she woke up 500 years later. The city had already been destroyed, and Seyi, freed from her hard work, was determined to travel through a completely changed world. She was supposed to travel freely, but her potion-making skills quickly become the talk of the town?! The genius alchemist's leisurely, slow-life journey begins!

(Source: Kadokawa, translated)