I'm working with some awesome engineers who have day jobs but still find time to write some posts. How do we make sure we make best use of their time?

Do "How we did X to improve Y" posts work? Do you want backgrounders to our key area or should we assume knowledge and give a bucketload of detail? I'm assuming nobody wants promotional content, but if we say how awesome we think something is because we solved our biggest pain point, does that count?