Salesforce Platform Developer I Course Notes

Know how Salesforce automation behaves inside a transaction. Prefer Flow when supported declarative elements satisfy the requirement; use Apex when code is justified. In Apex, think set-based: collect IDs, query once, process collections, and perform bulk DML outside per-record loops. Choose SOQL for structured object queries and SOSL for text search. Understand all-or-none versus partial DML, trigger context, order of execution, recursion, exception handling, and the fact that asynchronous Apex has its own limits rather than bypassing limits.

• Assuming Apex is better simply because it offers more control.

• Translate each scenario into four questions: What triggers the work? How many records? Must it be synchronous? What platform feature already does it?

Developer Fundamentals is about choosing platform-native designs that fit Salesforce's multitenant, metadata-driven model. Know when configuration is enough, when code is justified, how formula and roll-up summary fields behave, how lookup and master-detail relationships differ, how junction objects model many-to-many relationships, why External IDs matter to integrations, and why AI-assisted developer output still requires validation.

• Equating 'declarative first' with 'never use Apex.'

• Read relationship questions for three words: optionality, ownership, lifecycle.

For LWC scenarios, use the simplest supported data layer that meets the need: base record components/LDS and UI API first for supported record operations, GraphQL for flexible supported graph queries, and Apex for custom server logic. Wired data is reactive and should be treated as immutable; mutations are controlled imperatively. Communication follows containment: parent-to-child through public APIs, child-to-parent through DOM CustomEvent, and unrelated/cross-technology communication through Lightning Message Service. Security is layered: client isolation is not record authorization, and Apex must enforce the data-access rules the chosen execution mode requires.

• Reversing LWC communication: DOM events are not the general mechanism for unrelated components, and LMS is not specifically for 'contained' parent-child communication.

• Data-access ladder: Base/LDS -> UI API/GraphQL -> Apex when custom server logic is needed.

A+ exam prep means testing behavior rather than chasing coverage, debugging from evidence rather than guesses, and treating deployment as a controlled source-driven process. Tests should own deterministic data, assert outcomes, exercise boundary/security/bulk behavior, use `Test.startTest()`/`Test.stopTest()` around async work, and mock callouts. Debugging starts by reproducing the exact user/data/transaction path and inspecting the right evidence. Deploy from version-controlled source through an environment appropriate to the validation need, validate dependencies/tests/permissions, and verify after release.

• Treating code coverage as the purpose of testing.

• When the stem says deterministic/portable, create test-owned data and mock external boundaries.