Blogging was how I got started!
I was stuck at the entry level for almost four years during a very difficult job climate. There were no advancement and no stretch opportunities with my employer at the time due to restrictions beyond everyone's control and like you I was very short on time for portfolio building through personal projects. Also the work I was doing couldn't be shared through an online portfolio (I was working in government).
A colleague encouraged me to start blogging and sharing my ideas and lessons learned. Not only did that help build my technical capability but it also opened a lot of doors for me. You never know where it will take you and you will find that you get better at it the more you do it. I'd encourage you to keep at it and also consider posting to places like Medium as well!