Despite all the included batteries in Doom Emacs, I still wanted a way for the agenda view to refresh whenever I made a change to my agenda files.

So I came up with the following snippet:

(defun my/redo-all-agenda-buffers ()
  (interactive)
  (dolist (buffer (buffer-list))
    (when (derived-mode-p 'org-agenda-mode)
      (org-agenda-maybe-redo))))

(add-hook 'org-mode-hook
          (lambda ()
            (add-hook 'after-save-hook 'my/redo-all-agenda-buffers nil 'make-it-local)))

If you include this in your Emacs configuration file, next time you make a change to an Org file included in the agenda files list and save it, Emacs will rebuild the agenda view automatically.