Should I put a comma between "London" and "where" in the following sentence, or is it acceptable not to include it?
I live in London where I work at a coffeeshop brewing delicious coffee.
It is acceptable as there is no ambiguity in the sentence with who works at the coffeeshop.
However, there might be a comma after the coffeeshop as there is ambiguity whether you brew the delicious coffee or the coffeeshop is one where delicious coffee is brewed.
You may if you wish.
It is arguably "more correct" to include the comma, but few would note either its presence or absence in normal writing.
I do not know why somebody downvoted Varagrawal's answer, as it is 'correct', even though he and I have slightly different perspectives. His comment re the need for a comma after coffeeshop is worth considering. There is a degree of ambiguity present, but is is small and liable to be below the level that most would notice to the extent that the sentence felt uncomfortable.
However, 'English she is a strange beast' - the ambiguity is complicated by the fact that if you work at a coffee shop and if you brew delicious coffee as part of your job, then the concept of "the shop brewing delicious coffee" is to some extent incorporated in the statement about you. Also, to a somewhat lesser extent - if the coffee shop brews delicious coffee the action is to some extent also attributed to you - the more so if you are known in the context to be a Barrista or similar.
If it was important to me to make it clear who or what was doing the brewing then I would personally tend to address the small degree of ambiguity by rewording the sentence rather than by just adding a comma.