Kabaneri of the Iron Fortress: Season 1

Kabaneri of the Iron Fortress Recap 1: Gathering Light In a world revolutionized by industry, a mysterious virus transforms humans into aggressive, undead creatures known as Kabane. The only way to defeat them is by piercing their iron-protected hearts. Ikoma, a young engineer, creates a weapon called Tsuranukizutsu to fight the creatures. He meets Mumei, a girl exempt from the mandatory Kabane inspection, and together they face the growing threat of Kabane. The staff on Hayajiro, a steam locomotive transporting people and goods between stations, turns into Kabane during the night. Ikoma and Mumei must use their skills and bravery to protect their station and defeat the monsters threatening humanity.

You can stream Kabaneri of the Iron Fortress on: Crunchyroll

Some TV shows that have similar genres and were produced around the same time as Kabaneri of the Iron Fortress include Frieren: Beyond Journey's End, Invincible, Sengoku Youko (Original Japanese Version), Arcane: League of Legends, Mobile Suit Gundam GQuuuuuuX, Eminence in Shadow.