First start with an assignment that makes you work as free labor to write codes that can be directly plugged into their system. During the interview, ask about the company secrets from your previous companies that you worked for. (e.g. how you build exactly the model, what features you use). Being vague about how the company's been doing despite boasting about it using 'good PnL', 'good performance' without concrete numbers. One part I like is they are completely transparent about the work hours: you are expected to work way earlier than 9am and be expected to work overtime into night and need to be ready to work on weekends...blablabla..Very typical of an exploitative local company.