The emphasis is on internal packages. I rely on the internal
desktop, dabbrev and abbrev, xref, isearch, etc., and
external embark, consult, eglot, orderless,
programming-language specific, etc.. I've gotten a surprising amount
of mileage out of tempel for latex (see templates).
I've tried the whole bag of shiny packages for completion, navigation,
and all that (ivy, helm, ...), but I think Emacs has improved the
user experience to the point of obsoletion of these huge hammers. I
have a hard time understanding these over-powered packages, which
makes me less comfortable in my own home.
Configuration is defined in the lisp/ directory. Simple package-management macros are defined in init.el.
We're always standing on the shoulders of giants. The giant I'm standing on is protesilaos.com, who has done so much for the Emacs community in the past half-decade.