Move out of the way Bae Suzy and Nam Joo Hyuk fans, I am actually perhaps one of the few fans that started this because of Kim Seonho after seeing him on 1 Night 2 Days. So I started this while also knowing that he was going to be the second lead.
I do think that the story has a lot of potential. We have these two conflicting characters. One who is an orphan yet ultimately becomes successful due to stock / investment. The other who has a loving family and friends, but is unable to get his company to take off. Yet ultimately what happened is the writer wanted to bring this latter character -- the ML -- up to the standards of the FL. He's actually really smart, being able to win coding competitions, and really nice, which is actually his biggest folly as this is why he lacks drive. They try to make his character appealing by making him perhaps an ideal man, yet trying to make him complex by adding different faults. However, ultimately this just feels fake and forced, an obvious ploy. Especially when acted by a handsome man, he's essentially too perfect. It's only dampened by this annoying naivety and immaturity. He's unable to take responsibility for his actions, and this aspect never changes.
There's this hilarious moment (and by hilarious I mean not very hilarious at all) where Dosan and Jipyoung are verbally fighting and Dosan says 'you have everything while I have nothing'. We see Jipyoung's bafflement which I felt mirrored my own. Dosan is the one with two living parents and friends. Jipyoung on the other side lives by himself and lives by himself, ostracizing any possible relationships and keeping to himself. Dosan has what Jipyoung will never have.
The writers seems to fall in what many other Kdramas have fallen into, focusing too much on the romance rather than the character development. I do actually enjoy love triangles, yet will say that I believed there to be too much focus on this. It led Injae basically being cast off. Jipyoung also follows suit as his screentime is lowered to try and raise appeal of Dosan. Cheolsan and Yongsan also seem to have potential but are sidelined without any regards. Yet even Dalmi suffers as her focus is more on her relationship with Dosan and her characterization becomes 'wants to be successful' rather than any of the nuance that comes with her dad dying after trying to found his own company.
The time skip was predictable, yet still awful. The only highlight was being able to see Jipyoung and Dalmi's close relationship, yet that is ignored after thirty minutes. Besides that, it's just the characters becoming successful in life, as if that's the only way to be desirable in a relationship.

Many of the technical aspects were painfully inaccurate. I think for plot purposes it was fine, since too technical would've made it confusing so it focused on the plot related terms. But like, there should be no way that a lawyer reads the contract 2STO gives them and misinterprets it. Even I thought of it while watching, just figured that the contract must be good if no one was talking about it. The competition between Samsan Tech and the twins was also really eh because in reality it's not that simple and both teams can still get investors. It was a slight turn off for me but ultimately I understood why it was the way it was.

Overall, Kim Seonho <3