BASH and ZSH initialization sequence

BASH initialization

	Interactive login	Interactive non-login	Script
/etc/profile	A
/etc/bash.bashrc		A
~/.bashrc		B
~/.bash_profile	B1
~/.bash_login	B2
~/.profile	B3
BASH_ENV			A
~/.bash_logout	C

ZSH initialization

	Interactive login	Interactive non-login	Script
/etc/zshenv	A	A	A
~/.zshenv	B	B	B
/etc/zprofile	C
~/.zprofile	D
/etc/zshrc	E	C
~/.zshrc	F	D
/etc/zlogin	G
~/.zlogin	H
~/.zlogout	I
/etc/zlogout	J

Moral:

For bash, put stuff in ~/.bashrc, and make ~/.bash_profile source it.

For zsh, put stuff in ~/.zshrc, which is always executed.

Source

Bash loading flowchart