Why do developers struggle with social media marketing?
Short answer
Because the reflexes that make good engineering make bad posts. Engineers are trained toward precision, completeness and describing the system; social platforms reward compression, repetition and describing the outcome for one person. Posting feels like self-promotion rather than communication, and the accuracy instinct fights the compression the format demands.
The longer version
Two reflexes, both of them good engineering habits, work against you. The first is precision: engineers describe the system accurately and completely, and social platforms reward compressing it to a single outcome for a single person. The accurate version reads as flat, and the compressed version feels to the person writing it like an exaggeration.
The second is that posting about your own work feels like self-promotion rather than communication. That discomfort is real and it shows up in the writing as hedging — the post that apologises for existing, buries the point in the third paragraph, and ends on a question mark. Marketers do not have this reflex, which is most of why their version outperforms yours despite saying less.
There is a practical dodge for both. Write the post about the problem rather than the product. You are allowed to be as precise and interesting as you like about a problem, the discomfort disappears because you are not selling anything, and the product mentioned at the end lands better than any amount of direct pitching.
The full argument, with the rest of the picture around it:
Every Way to Promote a Product, and Why Developers Get Each One Wrong