Change the default WordPress title placeholder text

gistfile1.php

<?php
//If you only need to change one use this version.
function dwwp_change_title( $title_placeholder) {
        
        $screen = get_current_screen();

        if ( $screen->post_type == 'job' ) { //<--Your post type name goes here.
        
        $title_placeholder = 'I changed the title yo';
        
        }
        
        return $title_placeholder;
}
add_filter( 'enter_title_here', 'dwwp_change_title' );

//To change multiple placeholder titles, a switch statement is better.
function dwwp_change_title( $title_placeholder) {
        
        $screen = get_current_screen();

        switch ($title_placeholder) {

                case ( $screen->post_type == 'metabox' ):
                        return $title_placeholder = 'metabox title';
                        break;

                case ( $screen->post_type == 'job' ):
                        return $title_placeholder = 'job title';
                        break;

                default:
                        return $title_placeholder;

        }
}
add_filter( 'enter_title_here', 'dwwp_change_title' );