Can someone have a career outside of Chess and still compete at a Master level (NM, IM, GM, etc.)?

I'm just wondering if there are any known masters out there that have jobs and compete in chess as a hobby or side job. 

World Champion Max Euwe was only an "amateur" player.

Serious chess competitors do not have “jobs”. Once you reach FIDE 2300 or so you must make a decision to be a full time chess player , or call it a hobby. Without a full time coach and a regimented schedule, like the following, you will essentially plateau as far as rating, somewhere +\- 2300. A serious chess competitor will allot 25-30 hrs a week to study/play through games and 20 hours playing OTB, conservative numbers. 

This statement is true if he or she does not make a living off of chess but some other sources of income. If chess is your sole source of income then regardless of chess rating, you are considered a pro (professional) player.

Many players reach master level as students, then get a job and play chess as a hobby

Known one Master that was an engineer and programmer so sure, and GOOD at his job... but serious chess takes up a lot of time and I have yet to see any proof such investment is worthwhile. That guy's life was not stellar. 

Sure. I have a friend who was a NM and had a good job for many years until he retired. He came very close to reaching Senior Master at his peak rating.

Another example is the Englishman, Luke McShane. He became a GM, was in the thick of it in this years British Chess Championship (came in 2nd), and has a job in the securities industry.

the lack of day job options seems appalling

https://www.chess.com/article/view/a-cab-driver-who-knew-how-to-play-chess

This is true in many cases.  Similarly a friend of mine is a great jazz sax player who spent six hours a day studying music from the age of 6 until he got a scholarship to the music college at a university. At the university, he majored in both music and electrical engineering and has a full-time job outside of music.

amateur != beginner

amateur != novice

Max first taught mathematics for a living and later became a professor at the Universities of Rotterdam and Tilburg. He certainly earned some money playing chess and becoming WC, but chess was not his primary career, only a secondary one. Like Luke McShane mentioned already in this thread, Max's main profession was not chess. 

Smerdon.

Matthew Sadler quit pro chess in his 20's and now competes an an amateur - he's rated 2673

https://en.wikipedia.org/wiki/Alisa_Melekhina

start blogging, dropshipping or writing self-help books or w.e other bs is rewarded by the capitalist system because chess is one of the worst things you can make a profession of.  IT is essentially HIGHLY difficult to reach true mastery ( i mean top 1000 in the world, preferably top 100, not our kiddy master titles), there is an oversupply of said players and virtually NO economic demand for them. You literally have a better chance to make a living selling custom medieval fantasy weapons than a chess professional.

It has to be difficult, if not impossible, to combine high level chess with another career, probably more so now than in earlier times. Even Reshevsky, writing in 1948 wrote that "It is a difficult task to make a living from chess". He had passed up the 1944 US Championship tournament to study for the CPA exam (which he claimed was far more difficult than most chess games he had played). He went on, "Henceforth, I will confine my chess activity to vacations and occasional leaves-of-absence. Never again will I permit chess to interfere with the more important business of caring for my family." From Reshevsky's best games of chess, 1960 Dover edition, page 244.

That was quite a big span