Shady site Shady site not sure if the team behind are trustworthy with holding your algos data. I found other frameworks like backtrader that are easier to pick up and get working with quickly than LEAN. LEAN is poorly documenting making learning a huge hurdle. Also, I question the stability of their site because of the amount of bugs you can find in their UI and some that I encountered in plotting during backtrading. If you need an online IDE, Quantopian is far more reliable and documented and quicker to work with but still could have issues with data privacy.

I have been using QuantConnect for over… I have been using QuantConnect for over a year now. I started out using their free tier, which basically lets you do everything that you need to do to get started and more (coding, backtesting, access to historical data). Due to this I was able to learn how to use platform at my own pace without feeling pressured by any fees or costs. When I first started the documentation was still pretty spotty and it was difficult at first but I have always received fast and detailed replies by their staff and other community members, they have since improved their documentation and I have improved from being a beginner on the platform to being one of the helpful community members, I couldn't be happier with how QuantConnect and my own trading journey is evolving!

This is a pretty unique business This is a pretty unique business. I've learned a lot as an investor just creating and running simulations here. I really wish these folks the best and hope they can continue to grow and thrive.

Complex, difficult API, slow backtesting Extremely slow backtesting and very complex APi with bad documentation - be ready to spend many hours trying to understand the overly complex API that is changing all the time. And did I mention that support costs? So if a anything is complex you won't get answers from the staff unless you PAY them. I give them 2 stars as they have reasonably reliable data. The platform itself is only worth one star. note: if you ask about slowness or any other thing negative on their forum they delete the posts.

This is the best platform for… This is the best platform for individuals. I seldom subscribe to 'pro-account' things, but I did for this one. The dirty stuff like data cleansing, backtesting framework, error handling is done by them and I can focus on the fun stuff, printing money.