The goblin slayer fandom has kind of two sides? There's stuff on Archive of Our Own obviously, but I find the real character-driven stories sometimes get lost in the sea of smut there. I read this one called 'Burden' on SpaceBattles last year, it was a crossover with 'Berserk' of all things, and the tone matched so well it haunted me for days. The forums there let authors get feedback chapter-by-chapter, which shapes the plot in a cool way.
For a more polished, complete feel, FanFiction.net still has some absolute classics from right after the anime aired. 'The Unbroken Chain' by Paladin1776 is basically required reading if you want a deeper look at the Priestess's perspective. Just gotta sort by favorites and wade past the abandoned WIPs.
Honestly, my weird little secret source is Scribblehub. The tagging system is a mess, but I stumbled on a fantastic slow-burn GS/High Elf Archer fic there that I've never seen recced anywhere else. It feels like digging in a digital attic, but sometimes you strike gold.