Is this a custom template?

I've come across a blog at bench.co and looking at the page source it looks like they're running it using Squarespace.

I can't work out how they got the text overlays like they have, or how they got the "next" and "previous" buttons to appear at the bottom using built in settings, so I'm thinking it's custom built.

Is this an entirely custom template do you think? If it is, can anybody point me to a place where I might be able to find a Squarespace designer that could create me something similar?