Salesforce Flow Interview Questions and Answers

1What it is

Flow is Salesforce's point-and-click automation tool. You build logic from elements - get records, decide, loop, assign, create and update - on a canvas instead of writing code. There are five types, told apart by what starts them.

2Why it matters

Choosing the type is the first design decision, and it decides what the flow can do: only a screen flow can show a form, and only a record-triggered flow runs on its own when data changes.

3Example

4In short - say this in the interview

1What it is

A before-save flow ("Fast Field Updates") runs before the record is written and can only change fields on that same record. An after-save flow ("Actions and Related Records") runs after the save, when the record has its Id, and can work with other records and run actions.

2Why it matters

Before-save flows need no extra DML, so Salesforce says they are up to 10 times faster. After-save flows are needed for anything beyond the record itself - related records, emails, approvals, subflows.

3Example

4In short - say this in the interview

1What it is

$Record is the record that started the flow, with its new values. $Record__Prior holds the values from before the update, so the flow can compare old and new - the Flow version of Trigger.old.

2Why it matters

Most automation should run when something changes, not on every save. Without the comparison, a flow that sends an email when a deal is won sends it again every time the won deal is edited.

3Example

AND(
  ISCHANGED({!$Record.StageName}),
  ISPICKVAL({!$Record.StageName}, "Closed Won")
)

4In short - say this in the interview

1What it is

Flow first for most record automation, approvals, guided screens and simple integrations; Apex when the logic is complex, the data volume is large, or you need something Flow cannot do well.

2Why it matters

Admins can read and change a flow without a developer, so it is cheaper to maintain. But a flow with hundreds of elements is harder to test and debug than the same logic in a tested Apex class.

3Example

4In short - say this in the interview

1What it is

Yes. A flow runs inside the same transaction as Apex and shares its limits: every Get Records is a SOQL query and every Create, Update or Delete Records is a DML statement.

2Why it matters

Salesforce bulkifies record-triggered flows automatically: when 200 records are saved, the same element is grouped across all 200 flow runs, so one Get Records still costs one query. But an element inside a Loop runs once per item, and breaks the limits just like SOQL in an Apex loop.

3Example

Loop over Contacts
   ├─ Get Records: the contact's Account     <- one query per contact
   └─ Update Records: the Account            <- one DML per contact

Get Records: all the Accounts you need    <- one query
Loop over Contacts
   └─ Assignment: change values, add to a collection
Update Records: the whole collection         <- one DML

4In short - say this in the interview

1What it is

With a fault path: a separate connector from an element (Get, Create, Update, Delete Records, actions) that the flow follows if that element fails. {!$Flow.FaultMessage} holds the error text.

2Why it matters

Without a fault path, a failed element shows the user a generic "An unhandled fault has occurred" message and emails the admin. With one, you can log the error, show a clear message or try another route.

3Example

Create Records: Invoice
   ├─ success ──> next step
   └─ fault ────> Create Records: Error_Log__c
                     Message = {!$Flow.FaultMessage}
                  ──> Screen: "We could not create the invoice. The team has been told."

4In short - say this in the interview

1What it is

A flow called from another flow with the Subflow element. It takes input variables, does its job, and can return output variables.

2Why it matters

The same logic - creating a case, sending a notification, calculating a discount - is built once and reused by many flows. Change it in one place instead of in ten.

3Example

Record-triggered flow (Case)    ─┐
Screen flow (Support wizard)     ─┼──> Subflow: Notify_Account_Owner
Scheduled flow (Overdue cases)   ─┘       inputs:  recordId, message
                                           outputs: notified (Boolean)

4In short - say this in the interview

1What it is

Extra paths on an after-save record-triggered flow that run later. A scheduled path runs at a time relative to the save or to a date field. The Run Asynchronously path runs right after the transaction commits, in the background.

2Why it matters

They replace time-based workflow: "remind the owner 3 days before the close date" needs no scheduled Apex. The asynchronous path is where callouts and slow actions go, so they do not slow down the user's save.

3Example

4In short - say this in the interview

1What it is

Mark a public static method with @InvocableMethod. It then appears in Flow Builder as an Action. It takes a List and returns a List, so it is bulk-safe by design.

2Why it matters

It lets a flow do the one thing Flow is bad at - a complex calculation, a tricky query, a callout - while the rest of the process stays point-and-click.

3Example

public with sharing class DiscountAction {
    public class Request {
        @InvocableVariable(required=true) public Id opportunityId;
    }
    public class Result {
        @InvocableVariable public Decimal discount;
    }

    @InvocableMethod(label='Calculate Discount' description='Works out the discount for an opportunity')
    public static List<Result> calculate(List<Request> requests) {
        Set<Id> ids = new Set<Id>();
        for (Request r : requests) ids.add(r.opportunityId);
        Map<Id, Opportunity> opps = new Map<Id, Opportunity>(
            [SELECT Amount FROM Opportunity WHERE Id IN :ids]);   // one query for all

        List<Result> results = new List<Result>();
        for (Request r : requests) {
            Result res = new Result();
            Opportunity o = opps.get(r.opportunityId);
            res.discount = (o != null && o.Amount > 100000) ? 10 : 0;
            results.add(res);                                     // same order as requests
        }
        return results;
    }
}

4In short - say this in the interview

1What it is

You set it. Each record-triggered flow has a Trigger Order value from 1 to 2,000; flows on the same object and timing run from lowest to highest. Flow Trigger Explorer shows them all in order.

2Why it matters

When two flows change the same field, or one depends on another's result, the order decides the outcome. Without a set order, the result can change from one release to the next.

3Example

4In short - say this in the interview

1What it is

A screen flow shows forms to a user. You can place it on a Lightning record or home page, launch it from a quick action or button, add it to a utility bar, put it on an Experience Cloud site, or embed it in an LWC.

2Why it matters

Screen flows replace many small custom pages: guided case creation, onboarding checklists, a "log a call" wizard - built by an admin, with no code.

3Example

<template>
    <lightning-flow
        flow-api-name="Log_A_Call"
        flow-input-variables={inputs}
        onstatuschange={handleStatus}>
    </lightning-flow>
</template>

4In short - say this in the interview

1What it is

It depends on the type and the setting. Record-triggered and schedule-triggered flows run in system context. Screen and autolaunched flows run in user context by default, and can be set to system context, with or without sharing.

2Why it matters

A screen flow in system context without sharing can read and change records the user cannot see - useful for a controlled action, dangerous if it shows data on screen.

3Example

4In short - say this in the interview

1What it is

With the Debug button in Flow Builder, which runs the flow and shows every element, decision and variable value; with debug logs for record-triggered flows in a real save; and with the fault emails and Paused and Failed Flow Interviews page.

2Why it matters

Flows fail quietly inside a save shared with Apex and other flows. Knowing where to look is the difference between a five-minute fix and a lost afternoon.

3Example

4In short - say this in the interview

1What it is

With the Migrate to Flow tool in Setup, which converts a workflow rule or process into a record-triggered flow, then you test it, activate the flow and deactivate the old automation.

2Why it matters

Salesforce ended support for Workflow Rules and Process Builder at the end of 2025. Old automation still runs, but it gets no fixes, and every org is expected to move.

3Example

4In short - say this in the interview