Yea depends on the job, how you react to smoke, how heavy of a smoker you are, which type of bud you smoke as in indica vs sativa, and it also depends on whether you show external symptoms of being stoned that anyone might recognize.
I have done it a lot at work, and I work as a computer network engineer and electronics technician. It absolutely does not help me, I struggle with simple stuff when I am stoned but when I've been smoking really heavy all the time 24/7 then the negative effects are diminished but so is the high.
After a while if you smoke 24/7 your IQ drops substantially though. At least mine does. It's temporary mind you and it will all come back with a little work but your brain requires excercise just like your body does and that doesn't happen while stoned.
You can tell after taking a break from smoking 24/7 for a while (weeks to months) that some brain cells come back . At least I can.
In other words don't do it if you don't have to, you'll be able to get higher at night if you don't during the day and moderation in all things is always best.
No I'm not saying weed is bad for you or that it makes you permanently retarted or whatever, but it does hold you back if you over do it just like anything else.