How do you balance messaging to developers when (in b2b) they are usually not the buyers?

You have to message and target both, with different messages/tactics. 

Example:

Let’s say the platform team evaluate the product themselves. If the developers don’t see enough value in the product then they won’t use it, and the product will fail. My guidance is to understand the end user (developer) and the buyer needs and arm them with both. Target the developer as your champion if they are the end user by making a product that solves their use cases, and stay out of the way. Don't bombard them with sales, gradually let them find product value and then enable them with content for the buyer to convince the sale.