So about this series. When I first started it I did not have too high hopes, but it did come to surprise me. It has no specific story really, but It's very sweet and relaxing to watch. It made me happy and I like how you get to know many of the characters on a quite deep level. The serie is a comedy though for sure.

Bohn x Duen (main couple)
This couple was the "Tom and Jerry couple" for sure.
Bohn is a confident, play-boyish person who is used to get his way. And he falls head over heels for the innocent boy Duen. Duen is an innocent and caring person, but was not the typical "push-over bottom" and he did not hesitate to argue back, especially with Bohn where he probably just wanted to argue back. However, even if Bohn could seem like a bully sometimes he always showed care when it comes to Duen. This kind of pairing between two characters is a match that asks for a lot of understanding and patience from the the viewers or else they could easily be misunderstood.
Poy and Cooper's (the actors) chemistry is honestly very good. The couple was really sweet and fun to watch. Yes, people have been saying they were annoying and I'm not gonna argue back about that. They were really annoying and frustrating to watch sometimes. It had those jelousy and misunderstanding moments where you just wanted to smack them both. But in the end, there were still times where it was visible that they were both capable of putting their prides aside for a moment and to finally apologize to each other. I feel like this kind of dynamic was meant for this couple, and we do get to see how they finally overcomes thier issues.
People have complained they didn't have like "sex scenes" or "steamier scenes" but honestly, I don't think that is necessary at all. They (Duen) could be a bit dull about it but I still think that is okay. A couple doesn't need to have those scenes to be good and interesting. I think it's quite realistic since not everyone wants to do sexual stuff in real life either. You might feel like they didn't have any trust for one another even though they were boyfriends, and yes, that was kind of true but I still think there is more to them if you look closely. Being someone's boyfriend doesn't mean you trust them, trust is something that grows and we did get to see their trust slowly grow even though it took some time. They are a childish and bickering couple but I still find them very enjoyable. I can tell my love for them has only grown since the serie ended.

Ram x King (my favorites)
This couple had my whole heart. The chemistry between Perth and Lay was beautiful to watch and I think one of the reasons this couple was so enjoyable was because both the characters seperatly were so good and lovely as well. They are both pretty complex characters but they never seemed too tryhard to be deep.
King is a handsome engineering student and plant lover. He is known for being the best in all subjects and is a character impossible not to fall for. His love and care for plants allows him to be very observant and understanding of the people around him and to read them like open books. This is very visible in the serie as well. He is the dorky person with a fear of dogs, but yet manages to maintain his attractive and cool character.
Ram is a very interesting character but just as lovable. He is the introverted and guarded type, also self selective mute, meaning he chooses to be mute around people unless those he feels comfortable enough with. He is known in the serie for being the dog lover where he has 4 dogs that he seems to like more than the people around him. Ram had a really interesting and nice character development. Since he had very little dialoge and did not have many lines compared to the others Perth did a great job of giving life to his character through eyes and face expressions. I just loved how much they did with this character with so little.
The connection Ram and King have with each other is somewhat amazing to watch. Ram is very untalkative and therefor catches King's attention for being a litte different. This makes King wanting to know more about this quiet person and it turns out he understands him really way with no words needed. This is still one of my favorite couples and their communication chemistry sure is interesting. I heard some people were annoyed by King's fear of his emotions at the end but I find that dumb as well. It's a part of his character, being scared of your feelings must be one of the most common fears there is. Yes he ran away for a moment but I believe it's more complex than just another denial/confession situation. It's an emotion, it doesn't have to make fully sense and I personally think a lot of people can relate to King. He may seem like a very smart and calm person but he's got fears and flaws too right?

Mek x Boss
I know some people don't love this couple but I actually somewhat liked them.
Mek and Boss have had this "husband and wife" thing going on ever since tehy were freshmen, but while Boss saw it as more of a joke, Mek on the other hand had actually had been in love with him ever since then. Sadly he is too scared of losing Boss as a friend if he were to confess his feelings, so instead chooses to keep quiet and watching him from a distance while doing anything for him.
It probably doesn't sound very interesting but their sweet moments are there, and yes, we will be seeing scenes with Mek being hurt. I don't wanna spoil too much but I can tell, this couple goes surprisingly easy together. So about Mek's actor, Ryan. As I think everyone knows now he was dubbed with a really weird voice. It didn't suit him and yes, that voice did get real annoying sometimes. But after all, Mek was almost mute and did not speak much which added a nice touch to his character, and I believe Ryan couldn't speak thai which is where they probably should've casted someone else. But I mean, I personally think it works fine enough anyways, if you're not too sensetive about it. Boss, well he is the typical goofy character we've seen a lot of in bl and you might not think there is much to him but I still believe he's got more to offer, it's just hidden well. The "husband and wife" thing for example, he obviously did it because he somewhat always liked Mek but was too afraid to even dare and take a step forward, many people says he's insensitive but I think he might be just insecure, and just as Mek was, scared of losing his best friend.

Thara x Frong
I find it a bit hard to judge this couple since their story started almost at the ending. As we know, Frong was actually in love with Duen at first but later on gave up on him when he saw Duen choosing Bohn instead. Frong's story with Thara recently started but from what I've seen so far they are very caring and go pretty well together. I believe they will make a good couple in the coming season 2 if they get together some day.

Acting and cast:
The casts acting is surprisingly good! It's really well performed. The cast members seem to be very close. There are quite a lot of people but they all seem to be good friends already. I do know that Ryan (acting as Mek) sadly won't be in the season 2 because of reasons we do not fully know yet. How they will do with Mekboss couple is also not confirmed yet but a season 2 is confirmed.

OST:
I actually really love the OST! Both OST's are catchy and will easily get stuck in your head. They are yet a really good fit for the series and personally I like them. I especially liked the "love song" OST. When I searched the lyrics up I realized it has a very nice and important message as well:
-I want to tell you, beautiful love has no rules.
-It doesn't matter male of female as long as you love me.
-What's important is, someone knows my thoughts.

In the end, I think my engineer is a quite simple but still nice drama. It's very effective where it relies more on the character building and development instead of the story itself. I personally like this since I believe characters are important and the ones from my engineer I find very colorstrong and enjoyable. And even though the serie might not be masters of it I still think it delivers it well.