What is Apex?

Apex is a strongly-typed, object-oriented programming language built specifically for the Salesforce platform.

It allows developers to:
● Query and manipulate Salesforce data
● Apply complex business rules
● Create custom APIs
● Automate backend logic
● Integrate external systems

Apex executes on Salesforce servers, not in the browser.

Why Do We Need Apex?

Salesforce provides many declarative tools such as:
● Flow
● Validation Rules
● Approval Processes
● Formula Fields

These tools are great for simple automation, but they have limitations when:
● Business logic becomes complex
● Large data volumes must be processed
● Custom integrations are required
● Performance optimization is needed
● Reusable backend services are required

Apex fills this gap.

Where Does Apex Run?

Apex runs on the Salesforce application servers.

This provides:
● Automatic scalability
● Built-in security
● No infrastructure management
● High availability

Developers focus only on writing business logic.

Multi-Tenant Architecture and Apex

Salesforce operates on a multi-tenant architecture, where multiple organizations share the same infrastructure.

To ensure fairness and stability:
● Resource usage is strictly controlled
● Code execution is isolated
● Platform performance remains stable

This is enforced using governor limits.

What Are Governor Limits?

Governor limits restrict how much system resources Apex can consume in a single transaction.

Common limits include:
● Number of SOQL queries
● Number of DML statements
● CPU execution time
● Heap memory size
● Callout limits

These limits encourage developers to write optimized and scalable code.

When Should You Use Apex?

Use Apex when:
● Logic is too complex for Flow
● Backend validation is required
● Data processing involves large volumes
● External systems integration is needed
● Performance tuning is required
● Custom APIs must be exposed

Avoid Apex when:
● Simple validations can be handled declaratively
● Basic automation can be achieved using Flow

Always follow a declarative-first approach when possible.

Real-World Use Cases

Common real-world scenarios for Apex include:
● Auto-generating reference numbers
● Enforcing complex validation rules
● Processing large datasets using Batch Apex
● Calling external REST APIs
● Building custom REST services
● Generating PDFs and documents
● Orchestrating asynchronous jobs

Apex vs Declarative Tools (Quick Comparison)

Feature	Apex	Declarative Tools
Complexity	High	Low–Medium
Performance	Very High	Medium
Flexibility	Maximum	Limited
Maintenance	Developer-driven	Admin-driven
Scalability	Excellent	Moderate

Both approaches should be used strategically.

Conclusion

Apex is the backbone of Salesforce backend development.

By mastering Apex, you can:
● Build scalable systems
● Handle complex business logic
● Improve application performance
● Create enterprise-grade integrations

Happy Coding!

Apex Beginner to Advance

What is Apex in Salesforce?