Combination of giving back and trying to give insight into myself as an engineer.
On giving back - Throughout my career I've read tons of blog posts that have given me the information I needed to get started or un-stuck on a task. I hope when I write about things that someone out there may wonder 'how do I X?' and my blog post shows up when googling.
On giving insight into myself - I've had people reach out while I was doing a job search that said they looked over my blog posts and that gave them a positive signal which led them to reach out to me for a position.