Congrats on the first 10 paying customers!
My "thing" is still far from MVP and going live days so I am jealous.
It definitely sounds like you are headed in the right direction.
Definitely double down on creating more content relevant to the kind of developers who need your product (even if the search volume is smaller).
In the end traffic is kind of a vanity metric, just like follows on twitter, what matters is the kind of people are actively consuming your content and if they will ever become your customer/ brand ambassador.
Video might be a logical next step to experiment and in terms of paid traffic a good idea might be to set up retargeting campaigns (with double digit monthly ad spend, as in 50 bucks) for very specific pages visited.
Good luck on your journey!
