I was contacted by a recruiting agency that worked closely with Peloton. There was no phone direct contact with Peloton until the in person interview. They showed me the product and talked for a while, then sat me down for a pen and paper coding quiz. All the questions were the typical things you would find on google coding challenges, codeeval, and so on. None were exceptionally hard, but one or two were designed to see that you *really* knew Python well.
I did just fine, stumbled on the question listed below but even senior developers stumble there, apparently. In the end, the recruiter told me that they were really hoping for a more senior developer, but wanted to consider other (undoubtedly more affordable) options.
Know the ups and downs of Python. Know how try/catch/finally is different in Python than from other languages. Be good with runtime and space complexity. I was asked to write the simple fib sequence, so I did it recursively. They then asked me to do it dynamically, so I did. They then asked me to compare the runtime and space complexity of both, and state how much better the dynamic version was, if it was (obviously it was).
In the end I felt like my time was wasted. I did more than fine on the test, and they are a really diverse group so I couldn't imagine that it was a bad culture / personality fit. I think they just didn't want to pay for a senior developer and then realized that a recent-grad just isn't going to be able to get done what someone with 10+ years of experience can do.
My advice would be to inquire strongly about what they are *exactly* looking for.