Father of Constructs

Lorith's magic is fading. Centuries ago, heroic adventurers stopped the World Boss’ cycle of rebirth by reducing the creature to one hit point and sealing it away so no one would ever find it. But, by ending one calamity, they halted the natural flow of magic within the world and brought about the Havoc Plague.

With all civilization now on the brink of collapse, humanity's only hope is to find and kill the World Boss in order to restart the monster's rebirth cycle and bring back magic. When the Plagued janitor Harvey stumbles into a mysterious wreckage and accidentally kills the missing World Boss, he gains a million experience points, making him the target of almost all the would-be adventurers of the world. Burdened with ancient knowledge, and hunted by countless rivals, he must join with unlikely allies to do the unthinkable: find the reincarnated World Boss and defeat it again, before it can ravage the world anew.

Father of Constructs is an optimistic LitRPG novel with a dash of Slice of Life.