I would say definitely yes!Especially if it doesn't cost you anything (like a plane ticket to go there), if it doesn't then, it will only cost you a small amount of your time.You have to realise that performing well at interviews require skills and by doing a lot of interviews (hopefully) you will gain some experience and learn these skills. When I look back at the first interviews I did I performed poorly but I did learn a lot from the mistakes I did during them.Secondly concerning the lockup perdiod of 6months from my experience this is bullshit, I did interviews at a same a same bank in an interval of two weeks. Banks don't have (to my knowledge) black list of suckers they never want to see anymore. 'll add also that the lockup in banks due to HH sending your resume before is (from my experience), also bullshit .... At some point I was in contact with three headhunters at the same time and still had plenty of interviews.

The fact that the job is asking for "experience with FIX-based trading systems" shouts out loud that this is definately not a quant nor even a quant-developer role.It's pure and simply an IT systems role.If you think that you can use this job - if you get it - as a springboard to a quant type of job then I'm pretty sure you will be disappointed as it's extremely difficult to go from systems to quant directly even if you have the qualifcations.If you take this job you will be labelled, as mentioned in related threads, as nothing but a code monkey.Also as you don't have general systems experience your knoweldge - or lack of - will be easily picked up and there is a high possibilty that you will do farily poorly on their technical assessment of you in comparison to others who do have this sort of overall systems/coding experience.The only thing you might get out of it is that you'll get a bank's name on your CV which can't be a bad thing now can it?

You're not going to be interviewing for the same teams (without though they are within the same huge firm), so it won't ruin your chances.