Honestly, the author is way too fast paced with this story, they could have started slow, progressed the character and world development and then prepared Jarvis for the fight against the demon lord or whatever. It takes just a couple of chapters for Jarvis to win the fight and it takes even less time for him to develop better technology. Also, the system, it would have been better if he got knowledge rewards instead of straight up real people, it makes the story and effort shallow and the people feel soul-less. The characters as well feel a little shallow and empty, let them develop with more screen time or whatever is the equivalent.Overall, a great story concept and execution for a first try attempt, I assume. Just slow down to story and let it breath and settle a little.