Sleep regularly, sleep often
Probably the most common error we've seen is not getting enough sleep the night before. As we said earlier, the difference between you and your competitors is tiny, and losing a small percentage of your thinking ability through being tired has an exponential effect on your probability of getting a job. Hours in a bank can be quite hard, so it s really not a good idea to mention feeling tired. Not only will they not be impressed, but if you get drawn into a conversation about how it degrades your performance it won t end well. Conversely, a cup of coffee doesn't do any harm, but we have seen people who clearly had drunk rather too much, and it didn't work well for them.
Make eye contact
You need to make sure you look at your interrogators, they can smell fear. No need to stare at them, just remind yourself to look at them when they or you are speaking.
Apply for the right job
You may feel you are a unique individual, and an obvious match for the job. Sadly, that often turns out not to be the case. If you are applying for a job called 'Henchman to Assistant Quant's Minion—PD0701067,' then do try to include that in your application, prominently. If you don t include this, then you are critically dependent upon whoever opens your application guessing.
Don't send a blue CV Just don't, OK?
The word barbarian comes from the ancient Greeks who took anyone who didn't speak Greek as making 'bar bub bar' noises, like a drunk Homer Simpson, not Barbarian as in the icy commanding tones of Governor Schwarzenegger. Although Dr Simpson has enjoyed careers as an astronaut, rock star and nuclear engineer, few of us would hire him as a quant. It's important to get the right balance between gushing at people so fast that they have trouble following you, or being too quiet. You should try to practice looking at the reaction of people talking to you, and if the interviewer is clearly trying to move on, you usually should accept that. If you think of the conversation style used when first meeting someone you find attractive, you won't go far wrong. (Just remember it's a first date.)
It is also the case that no one wants to discriminate against those who aren't English speakers. This is good, but means that if you aren't understood they may just skip over what you say, rather than pass comment on your accent. This is especially true when having a telephone interview where you will not get visual feedback, and the sound quality is degraded.
Read your CV
Make sure that your CV is correct. A surprisingly large number have dates that are clearly wrong, or that by accident give the wrong impression. These worry interviewers a lot, and if your dates don't match, this can lose you an offer when they do the basic background check on all employees. Also read it to work out which questions it might provoke them to ask, 'Why did you pick X?,' 'I see you've done a lot of Y, here's a hard question about it.'
Mobile phone interviews
We're old people (>35), and thus sometimes use quaint phone technology which involves long wires physically connecting us to a huge ancient Unix computer miles away (yes, we still use miles). A typical quant has done enough physics to know that you can actually talk down copper wires rather than a 1 mm thick cell phone that has more processing capacity than its owner.
Sadly, the quality of cell phone speech is hideously degraded, and on many systems you can't both talk at the same time. This is occasionally awkward when both speakers have the same first language, but if both have English as a second language neither comes out of the conversation impressed with the other.
Do not attempt to do a phone interview on a cell phone.