At the first the story went well, everything is good, the acting from actress/actors, the cinematography, the music, the story line but it turns to be messy on the half of full episode.

Lets talk about the love story first;
It doesn't matter the female lead who will end up with (first or second lead), its just about there're so many unrealistic things in their relationship, the writer made the female lead as a strong and optimistic woman, but she's changed since meet the first lead, its only takes several month but she's already fall in love with him that deep, but at the same time forgot about her first love for 15 years. She's live on a fairy tale, meet a random guy for several month but she cant move on 3 year, where is the strong woman from the first episode goes? The writer should make their relationship (female & male first lead) a bit longer, it doesn't make sense to fall in love that quick in their age, they're not a teenager anymore.

Lets talk about the character development side:
the writer want make the first male lead looks realistic but at the same time make the second lead unrealistic.
Is it just me who find the first lead have no character development at all? after the 3 years jump time i thought he would change, but no, he's still unmature guy who cant make a straight line between bussiness and personal thing. I cant get his point of view at all.
and the second lead, the writer made him unrealistic because he is too good to be true, his flaw is only his harsh words. Till the end the writer make him as an emotional punching bag for the whole episode and give nothing.
the samsan tech's team is much better after the 3 years time jump, they learn to be wiser, and solve the problem they had before.
and, startup has 2 female leads but the one is just a cameo, her screen time is so rare, she's will be an impactful character if the writer focus on her too.

Many people complaining about this drama's because shows us more about the love side not the bussiness side, and yes i agree, that was a wasted potential. The writer should end the love triangle earlier if she wouldn't do some plot twist, at the end the female lead will choose the first lead, right? so dont make it waste. If only she end the love triangle earlier, and focusing on the bussiness side i think it would be more interesting than seeing the episode is mostly talk about a love triangle till the end.

But i want to respected all actors/actresess, their acting are amazing, they deliver the emotions very well. The cinematography too, i love the color grading they use. and last the osts are beautiful! especially day & night and one day, it just suits with the cinematography mood.

I edited this after startup ends.
In twitter a lot of people missunderstanding about "sailing without the map is marvelous", they said its okay to do that in business things because in the end many of poeple still get the goals (as you can see on the ending), this drama's romanticizing it so much, but in real life it is 1 out of 10000000 people who can suffer with that sailing without the map, there's will no business consultant/analyst if sailing without the map is good enough.