Write the test class for this Apex
Not coverage — assertions. This prompt produces tests that would actually catch the bug you will write next month.
Test data factory, the minimal version
One class, builder-style defaults, no framework — the 80% of a test factory most orgs actually need.
Bulk-safe trigger handler skeleton
The five-method handler shape that survives 200-record batches — collect, query once, map, loop, DML once.
Apex Hours
Community-run sessions on everything platform — the archive alone is a curriculum.
Salesforce Developer Documentation
The primary source. Learn to read it before any course — including mine.
Advanced Apex Programming
Dan Appleman's book is still the deepest treatment of Apex patterns in print — read it after your first triggers, not before.
The Apex mistakes I still see in every org
Fifteen years of the same five mistakes: queries in loops, tests without assertions, triggers with opinions, hardcoded Ids, and empty catch blocks.