[adetrest]

Is "rebuilding rails" still relevant? The website has a 2010-ish design vibe and it seems to talk about rails 3 being cutting age while we're now at rails 5. One image has (c) 2012.

Didnt know about the book, so I'm interested, but I can't tell if it's worth buying because of the above.

[joshmn]

It's very much still relevant. It won't give you very low-level details but it'll explain a lot of the metaprogramming (others call it magic) that Rails has.