I took some time to learn about cubic-bezier curves and how to read them because I noticed that a lot of brand design systems include cubic-bezier curve values and After Effects velocity values in their motion design specs section. I really wanted to understand the relationship between the two and learn how to translate the cubic-bezier values to AE values. Here is what I learned so far. 
The x1 and x2 (Horizontal) coordinates translate to the After Effects velocity influence values. The y1 and y2 (vertical) coordinates translate to the pixels/second (speed) values. It's easy to notice the velocity values pattern once you understand how to translate it.
So for your example cubic-bezier(0.65, 0, 0.35, 1) translates to:
- x1: 0.65 = Outgoing Velocity 65% influence value
- x2: 0.35 = Incoming Velocity 65% influence value
Now I do not quite understand how the "pixels/second" parameter works so I will leave that for someone else to dive in and explain as I need some help understanding it as well. But essentially the X axis reads from left to right starting at 0 and ending at 1, outgoing handles drag from the left and incoming handles drag from the right. I hope this helps