Working across both sides.
WHAT IT MEANS
Working on both the interface and the server side.
WHAT IT REQUIRES
Understanding of both, and of what belongs where.
WHAT BELONGS ON THE SERVER
Anything requiring trust Anything requiring secrets Authoritative data and validation
WHAT BELONGS IN THE BROWSER
Presentation Interaction Convenience validation
WHAT IS FREQUENTLY DUPLICATED
Validation, deliberately, in both places.
WHY
Browser validation for convenience, server validation for correctness.
WHAT TO AVOID
Trusting anything the browser sends Business rules implemented only in the browser Logic duplicated accidentally, diverging over time
WHAT FULL-STACK DOES NOT MEAN
Equal depth in everything.
WHAT IS REALISTIC
Competence across, with depth somewhere.
WHAT MATTERS MOST
Understanding where a responsibility belongs.
WHAT THAT PREVENTS
Security faults, and architecture that cannot be maintained.
WHAT TO LEARN ALONGSIDE
Deployment, databases and basic operations, since full-stack work touches all of them.
