Drinking Solo (2016)

These two dramas are written by the same team so there are quite a few similarities:

Slice of life rom-coms with a similar feel
Characters - two male love interests older lone tsundere who has had a career change for some reason and a younger kind love interest with a team of friends,weird/lazy boss, a funny co-worker, and an outspoken best friend
Comedic elements - running jokes assorted forms of humor

Differences: setting/careers and interests are different - in Drinking Solo they are Teachers interested in Drinking and in A Poem a Day they are medical therapists interested in Poetry.

Both have...
- the same screenwriter
- a variety of office/co-worker relationships
- simple but sweet and light hearted plot
- several people with different personal struggles
- Big and younger "brother" fall in love with the same girl
- KIM WON HAE

*edit*
Drinking Solo Cameos....

Both have couples that end up falling in love while having a drink/meal together. Both have a somewhat arrogant male lead and a female lead that is working hard to succeed in her work life.

Another Ha Seok Jin drama with a love triangle with his brother. And the female lead is his younger brother teacher

It has the same vibes with the leads. The male lead of drinking solo and the female lead of cheers to me has the same solo theme between them. Both shows involve food and drinks.

The main protagonist is an adult male who likes to isolate himself at a certain part of the day after his working hours are over and enjoy a certain amount of food + a drink (alcochol) that work well together. That is his secret pleasure.

It has same feeling of
Teacher and student........,
Older woman/young man...... ,
But in drinking solo ....... Student is second male lead

Both star Ha Suk Jin where he is a little more aloof and seems to have very high standards. He's a little more willing to offer help in Your House Helper than he is in Drinking Solo, but he proves to have a softer side after the main character breaks him down a little.

Both dramas are about food...........................................................................................

Both are office dramas, starring Ha Suk Jin in which he plays a somewhat despicable man (he is a better human in RO), while the female worker is honest and desperate by default (more desperate in DS)..

The leading men in both shows are so confident in their abilities and worth that doesn't realise their unfairness to others as it mostly doesn't came with a bad feeling, but is with a rather sharp tongue and judgement. Both consider themself elites. Both are somewhat abusive towards the female lead. Female lead in both is being considerate by them below their level and is a crybaby with a lot of troubles.

Both involve a man and a woman having the same profession. While the man is considerate "elite" in his, the woman is struggling heavilly both for recognition and with money.

They have the same realistic but comedic feeling. Both deal with the struggles of korean youth/young adults and the main male leads are anti-social.

Let's Eat and Drinking Solo are about love for food, both have mukbang and nice characters you can relate to.

Both have the same calm and cheerful mood focused on eating (Dae Jang Geum is watching) and drinking (Drinking Solo). Both have enjoyable romance and funny characters among the company workers.