Why this matters
Many organizations start with Flow because it's accessible. But as your platform grows, you'll encounter situations where Flow is less convenient: lots of data, complicated calculations, connections with other systems. Then you need Apex. The smartest approach isn't "Flow only" or "everything in Apex", but knowing when to choose which.
What is Flow?
Flow is the visual way of automating in Salesforce. You build with blocks and can quickly automate processes.
⚙️ What can you do with it?
create or update records, make decisions, send emails, show screens to users.
Benefits
- No coding knowledge needed
- Quick to build and modify
- Clear visibility for admins
When not?
Less suitable for complex calculations, less suitable for many records at once (bulk), less control over error handling.
What is Apex?
Apex is Salesforce's programming language.
🧠 What do you use Apex for?
- complex business logic,
- integrations with external systems (APIs),
- batch processing of large amounts of data,
- reusable services that you can call from flows or other code.
Benefits
- A lot of control
- Fast and scalable
- Good error handling and logging
- Reusable (classes)
When not?
- You need development knowledge
- Changes go through deployments
- Slightly more maintenance
Many teams start in Flow and encapsulate the calculation logic in an Apex class later. That's normal — you don't have to choose code all at once.
Rule of thumb
Use Flow
- Process is simple
- User needs to click through it
- It concerns 1 or a few records
- Admins should be able to adjust it themselves
Use Apex
- There's a lot of data at once
- Calculations based on multiple tables/rules
- There's an external connection
- Robust error handling is desired
Use Flow + Apex
- User-friendly Flow desired
- …but calculation logic is too heavy for Flow
- Have Flow call an Apex class
3 fictional practical examples
☕ CoffeeCloud – welcome process for new customer
CoffeeCloud supplies coffee machines to small businesses. As soon as a new customer is created in Salesforce, the following should happen automatically:
- a welcome email goes out,
- a task is created for the account manager to follow up after 7 days.
This can be done 100% with a Record-Triggered Flow on Account. The Flow checks: "Is this a new customer?" → yes → send email template → create task.
Why Flow:
- Logic is simple,
- Adjusted occasionally by the business,
- No heavy calculations.
☀️ Solarize Energy – quote with calculation
Solarize sells solar panels. When creating a quote, the user needs to fill in a few values (roof area, tilt angle, region) and based on that, the expected yield and price should be calculated.
Create a Screen Flow for the user (who fills everything in), but have that Flow call an Apex class in the background that does the calculation and returns the result. The Flow then displays the calculated values and saves the quote.
Why Flow + Apex:
- Flow for the user experience,
- Apex for the calculations (because that can become more complex later),
- Admins can adjust the Flow without breaking open the Apex logic.
🚚 FreshTrack Logistics – nightly data processing
FreshTrack transports refrigerated products. Every night, updates come in from an external system (GPS/temperature). Thousands of records need to be updated in Salesforce.
A scheduled Apex Batch Class that runs at night, retrieves the changed records, processes them and logs errors in a custom object.
Why Apex:
- Large numbers of records (bulk),
- Integration with external system,
- Good error handling and retries can be built in.