I won't say I have "experience" but quantconnect.com is as good a platform as I've found for C#. Their engine is open source so you don't have to rely on them either, though you'll need to provide your own data if you run it yourself.
QuantConnect also offers tick-level data, though not full resolution if memory serves. Still way ahead of Quantopian in any case.
Futures have millisecond timestamps (trades/quotes), equity trade ticks are rounded to the nearest second, cfd/forex are millisecond quote bars. For options we have minute resolution data =)
please use a disclaimer if and when you are promoting your own company...
Does the "we" pronoun not make this sufficiently clear?
Worth noting though that Options data is super hard to get running on QuantConnect due to the memory limits and lack of index options.
Agree, we're working on making it easier now. We patched a bug today which should make it more efficient.
Do you have a public email for getting in touch with you? I'm interested in chatting.