It's well thought through and commented. Read for example the commented design decisions of https://github.com/sqlite/sqlite/blob/master/src/pager.c https://git

It's well thought through and commented. Read for example the commented design decisions of https://github.com/sqlite/sqlite/blob/master/src/pager.c https://github.com/sqlite/sqlite/blob/master/src/pager.c or os_unix.c