Pros
QuantConnect provides a great chance to learn powerful technical skills if you want to be an expert in the quantitative finance field, especially, when you have no working experience and eagerly want one.
It is a great place where you can put your idea into realization as you can always freely discuss your idea with the managers and they are very open-minded and sincerely take your reasonable advice.
It is also a fast-growth work station. Every year there is rapid development in products and significant growth in company size.
The working environment is rather flexible. A lot of worldwide employees work remotely but have catch-up meetings every day to make sure of the progress. The new office in Seattle is very beautiful and heartwarming. Very good scenery, chess, table games, team lunch, etc.
Even though I left QC for several years, the boss frequently reached out to me for events and opportunities. You feel you are never far away and always welcomed.
Kontras
Sometimes the boss is too busy and you have to take the initiative to remind him of personal stuff.