I applied through a staffing agency. The process took 2 weeks. I interviewed at FlexTrade Systems Inc. in Jun 2014
Interview
First step involved a code review of around 200-300 lines of Java code. Not too difficult and took only 30 minutes to complete.
Next step involved a 70 minute technical test writing Java code (or pseudo code, which ever you preferred). There were around 15 questions altogether. Some were easy such as finding the average and mode in an array of numbers. Harder was sorting a list of numbers. The second question involved writing out output from a small piece of code. The 3rd question involved implementing the Iterator/Iterable interface for a nested List data structure. The test wasn't too difficult as long as you worked steadily through the test and didn't spend too much time thinking about how to implement a solution. I only had a handful of minutes left to double check my answers. Compared to other on-site technical tests I've done with other companies, there test was by far the most demanding.
If you pass that test, then you face 2 HR/technical interviews. Questions ranged from how I go about developing code to OO design and details of agile development. They also go through your CV.
I interviewed at FlexTrade Systems Inc. (Milwaukee, WI)
Interview
Exam was very difficult. The hackerank does not allow you to use any outside resources and I was unable to recall syntax for functional programming which was listed as a small requirement on the application.
I interviewed at FlexTrade Systems Inc. (London, England) in May 2026
Interview
First took me through an intro call, which was simple enough explaining my career from start to finish. I'm a junior dev, so I focused mainly on my one previously role, talked about arch, day to day and core language uses and application.
Recieved a private LeetCode link to complete within 7 days, was told 2 hours to complete but the LeetCode timer was set to 3 hours.
Passed 4/5 test cases, took 2h27 to submit the single question. Did a bit of digging after submitting - found this specific problem was not public. Really enjoyed the challenge, but my code must not have been flexible enough (that fifth test case failing caught me so bad and I couldn't get my head round it annoyingly - big fluster). Did not receive next round invite.
I applied online. The process took 2 weeks. I interviewed at FlexTrade Systems Inc. (London, England) in Nov 2025
Interview
Had a quick call with HR about the process, then sent a HackerRank (which could only be done in Java) easy(ish) lc. Then a half an hour behavioural interview with a senior engineer, before on-site which was 2 hours or so, another simple Java problem on the whiteboard, a simple math/data structure problem, and then general behavioural and team experience questions, from engineers on the team and then with the team lead. Rejected a couple days later, said other candidates were a better fit.
Interview questions [1]
Question 1
Do you like working in a small team? Have you ever done a project where you've owned the whole stack end-to-end? What's your process for debugging something? Tell me a time you had to manage conflict.