Tenshoku no Shinden o Hirakimashita is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

What was born as a villager, no matter how much effort, remains a villager and never becomes a swordsman. This is the world where everyone’s life has been determined by the innate “job”. And a young man was summoned to this different world with a certain ability. The ability of the main character, Kaname Morimoto, was able to brilliantly “change jobs” = job change ability!!