Creating roguelikes is a common pasttime among hobbyist game devs. Lower asset requirements free up development time to focus on the true nuts and bolts that make games both entertaining and challenging, i.e. mechanics. As with any type of game, there is a wide range of components and considerations that go into creating a roguelike, and there are as many solutions as there are developers.
That said, the core "roguelike problem set" is also fairly well defined, with most developers having to tackle similar problems that might not all apply to games outside the genre. As such, it's interesting to look at many different approaches to the same set of problems.
About a year ago I began hosting a series called "FAQ Friday" over on /r/roguelikedev, where we ask roguelike developers to discuss a specific aspect of development as it relates to their own project.
Participation has been great, and you'll find input from the devs of Nethack 4, DCSS, Cogmind, Cardinal Quest 2, Incursion, Armoured Commander, and a huge range of other games in development you may not have heard of yet.
If you're interested in an under-the-hood look at roguelikes in development, or thinking of developing a roguelike of your own, consider checking out some of these threads:
For a compiled list of many in-development roguelikes and their devs who have contributed to the FAQs so far, see this page.
We will continue to bring you more FAQs throughout 2016--they're currently on a biweekly schedule. /r/roguelikedev is a great place for beginners and experts alike to learn and discuss roguelike development. Check out our sidebar for useful tutorials, resources, and tools!