Lessons for frontend engineers who can ship features but want the mental models — why rendering strategies exist, where state should live, what the network does to your UI. Plain HTML to heavily stateful apps, with working demos you can poke.
From plain HTML to SSR and back. Every rendering strategy exists because the previous one hit a wall — feel each wall, and the choice becomes obvious.
Where state lives, what is derived, and why most UI bugs are two copies of the truth disagreeing.
Requests finish out of order, users click twice, networks lie. Loading states, cancellation, and optimistic updates done honestly.
The skills that survive the next framework: the platform underneath, logic that outlives views, components designed like APIs, and a knowledge portfolio that compounds instead of depreciating.