Salesforce-Flow-Design

# Salesforce Flow Design and Validation

Apply these checks to every Flow you design, build, or review.

Step 1 — Confirm Flow Is the Right Tool

Before designing a Flow, verify that a lighter-weight declarative option cannot solve the problem:

| Requirement | Best tool |

|---|---|

| Calculate a field value with no side effects | Formula field |

| Prevent a bad record save with a user message | Validation rule |

| Sum or count child records on a parent | Roll-up Summary field |

| Complex multi-object logic, callouts, or high volume | Apex (Queueable / Batch) — not Flow |

| Everything else | Flow ✓ |

If you are building a Flow that could be replaced by a formula field or validation rule, ask the user to confirm the requirement is genuinely more complex.

Step 2 — Select the Correct Flow Type

| Use case | Flow type | Key constraint |

|---|---|---|

| Update a field on the same record before it is saved | Before-save Record-Triggered | Cannot send emails, make callouts, or change related records |

| Create/update related records, emails, callouts | After-save Record-Triggered | Runs after commit — avoid recursion traps |

| Guide a user through a multi-step UI process | Screen Flow | Cannot be triggered by a record event automatically |

| Reusable background logic called from another Flow | Autolaunched (Subflow) | Input/output variables define the contract |

| Logic invoked from Apex `@InvocableMethod` | Autolaunched (Invocable) | Must declare input/output variables |

| Time-based batch processing | Scheduled Flow | Runs in batch context — respect governor limits |

| Respond to events (Platform Events / CDC) | Platform Event–Triggered | Runs asynchronously — eventual consistency |

**Decision rule**: choose before-save when you only need to change the triggering record's own fields. Move to after-save the moment you need to touch related records, send emails, or make callouts.

Step 3 — Bulk Safety Checklist

These patterns are governor limit failures at scale. Check for all of them before the Flow is activated.

DML in Loops — Automatic Fail

Loop element
  └── Create Records / Update Records / Delete Records  ← ❌ DML inside loop

Fix: collect records inside the loop into a collection variable, then run the DML element **outside** the loop.

Get Records in Loops — Automatic Fail

Loop element
  └── Get Records  ← ❌ SOQL inside loop

Fix: perform the Get Records query **before** the loop, then loop over the collection variable.

Correct Bulk Pattern

Get Records — collect all records in one query
└── Loop over the collection variable
    └── Decision / Assignment (no DML, no Get Records)
└── After the loop: Create/Update/Delete Records — one DML operation

Transform vs Loop

When the goal is reshaping a collection (e.g. mapping field values from one object to another), use the **Transform** element instead of a Loop + Assignment pattern. Transform is bulk-safe by design and produces cleaner Flow graphs.

Step 4 — Fault Path Requirements

Every element that can fail at runtime must have a fault connector. Flows without fault paths surface raw system errors to users.

Elements That Require Fault Connectors

- Create Records

- Update Records

- Delete Records

- Get Records (when accessing a required record that might not exist)

- Send Email

- HTTP Callout / External Service action

- Apex action (invocable)

- Subflow (if the subflow can throw a fault)

Fault Handler Pattern

Fault connector → Log Error (Create Records on a logging object or fire a Platform Event)
               → Screen element with user-friendly message (Screen Flows)
               → Stop / End element (Record-Triggered Flows)

Never connect a fault path back to the same element that faulted — this creates an infinite loop.

Step 5 — Automation Density Check

Before deploying, verify there are no overlapping automations on the same object and trigger event:

- Other active Record-Triggered Flows o