Hey Reader,

Last week, a dev messaged me: "I ran cache:flush instead of cache:clean on prod, and now our site's throwing errors. Why?"

This is exactly why Adobe puts this type of question on the certification exam.

On the surface, cache:clean and cache:flush seem identical. Both clear the cache and make changes visible. But one deletes from matching tags, and the other nukes the entire cache storage (including external services!).

When you flush, you are also wiping caches from OTHER applications, like Redis. Sometimes that's what you want, but it's possible it can unintendedly take down your store.

The Adobe cert exam (shameless plug: cert-prep course launch promo ends today!) is full of these "seems the same but isn't" questions:

• cache:clean vs cache:flush
• custom vs extension attributes
• config:set vs env variables
• grouped vs bundle products

These are questions designed to catch devs who memorized commands but never understood the WHY.

I just opened up a few more related lessons for the cert-prep course, check them out below 👇

Mark Shust Teacher / M.academy Say hi 👋 on LinkedIn, YouTube & X​

Differences between cache clean and flush in Magento

One deletes by tags, the other nukes everything including shared Redis data.

Knowing the difference prevents production disasters AND nails a guaranteed exam question:

Watch →

Custom vs. extension attributes in Magento

Both add data to entities, but one works directly with the core API.

Saves hours refactoring if you choose wrong:

Watch →

Add a column to the Magento 2 sales order database table

Want to create an extension attribute?

This is simple... and it isn't. Learn exactly how to create one by setting up a custom database table and hooking into the core API with a plugin:

Read →

Compare configurable, grouped, and bundle products in Magento

Clients always ask "which product type should we use?"

Get this wrong and you could be rebuilding your entire catalog later:

Watch →

Thank you for being a University student 🧡

Hope you are enjoying the cert-prep course so far!

Feel free to drop over on Campus and share how your experience has been going so far. I've also asked for course platform feature requests in the Real-Time Chat space, so be sure to check that out.

Campus →

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