Amazing community of makers, docs. It really makes launching a product easy not to mention the fact that it's completely open source!
Blogstatic powers 3 of my current products. It's my go-to blogging platform, the UI is beautifully simple and easy to use and everything "just works". I use blogstatic's API too to render the content.
I've used Plunk for a few years now on a number of different products and use it for all transactional emails on the product. Never had one fail or end up in the spam folder yet! Highly recommend!