Ah, the ever-reliable IKEA KALLAX: a timeless, affordable shelving unit that's available in a variety of sizes and colors and is useful for holding books, records, storage bins, objets d'art, snakes, and so much more. Yes, of course, snakes...
I have to say, the wood of the KALLAX looks pretty beautiful with all the organic matter, and the plants and rocks inside are all well chosen and arranged. It's well done and very nicely lit—and the LEDs add an extra bit of flair and fun. I hope the snake (apologies, I don't know the snake's name) has a lovely life in it.
If you happen to have a KALLAX—or an EXPEDIT, its earlier incarnation—and a pet snake lying about, a magical habitat like this can totally be yours. And the snake's. This ingenious snake-housing solution was created by lefthagan, who has helpfully provided tons of process photos if you too would like to treat yo snake. There are even a few 123D Design renderings and a brief discussion of the legal parameters for housing corn snakes in Sweden; I assume the former will be useful to more people than the latter (though if you aren't in Sweden, you might want to brush up on the legalities of housing a snake where you do live, and the safety of a DIY solution either way—for you, the snake, and others).
This is actually a very elaborate project, with "channels for the thermometer cables," a heat lamp with guard, and several kinds of lining, and the step-by-step project description is similarly complex. The poster is very helpful about frankly pointing out what worked and what didn't (example: use glass, not Plexiglas) so that you can learn from their process. There are many different KALLAX configurations, so hopefully you'll be able to find one that fits your snake's needs. I don't know what lefthagan is storing in the lower cubbies, but they seem like they would be very useful for holding food, extra rocks, spare heat lamp bulbs, and whatever else a terrarium needs.
If you do tackle a similar project for a constrictor that can grow up to 6', there is one thing I'd like you to get a definitive answer on before you begin that our intrepid OP didn't happen to: "I'm not sure how strong a corn snake becomes."
Thank you, lefthagan!