Pros
I had an offer to join a major Wall Street bank but turned them down once I interviewed with Flow Traders. This is an amazing place to work. The company is technology focused and adopts a relaxed culture. You are surrounded with friendly colleagues and collaborate on cutting edge technology to help the firm grow. The environment is collaborative and entrepreneurial. You feel like you are working at a startup company where management encourages "out of the box" thinking. The learning curve set here is very high but people here are very supportive and will help you with training. I started in May and after a month, I was sent to Amsterdam for 2 1/2 weeks for training. Amazing work life balance with catered lunch daily, fully stocked pantry, free gym membership and after work team building events.
Cons
Realistically, keep in mind this is a HFT firm that comes with a high pace trading environment so expect to have long days. Except for developers, working from home is not an option.