Salesforce Integration Interview Questions for Experienced

Leave a Comment / Blog / By

Preparing for a Salesforce Integration interview?

Integration is one of the most important and high-demand skills in the Salesforce ecosystem. Whether you’re a Salesforce Developer, Integration Specialist, or Technical Architect, you must clearly understand APIs, authentication, patterns, and middleware concepts.

In this detailed guide, I’ll explain every commonly asked Salesforce Integration Interview Question in simple English — step by step — so you can confidently answer them in interviews.

Let’s begin.

1. What is Integration?

Integration means connecting two or more systems so they can share data and communicate with each other.

Example:

  • Salesforce connected to ERP

  • Salesforce connected to Payment Gateway

  • Salesforce connected to Marketing Automation tool

In simple words:
Integration allows different applications to work together.

2. What Are Web Services?

Web services are APIs that allow systems to communicate over the internet.

They usually use:

  • HTTP protocol

  • XML or JSON format

There are two main types:

  • REST Web Services

  • SOAP Web Services

3. What Is the Difference Between JSON and XML?

Feature JSON XML
Format Lightweight Heavy
Readability Easy Verbose
Used in REST APIs SOAP APIs
Parsing Faster Slower

JSON is modern and preferred for REST APIs.
XML is commonly used in SOAP-based services.

4. What Is REST API?

REST (Representational State Transfer) API is a lightweight web service that uses:

  • HTTP methods (GET, POST, PUT, DELETE)

  • JSON format

Salesforce provides a REST API for data operations.

It is simple, fast, and widely used.

5. What Is SOAP API?

SOAP (Simple Object Access Protocol) is a protocol-based web service.

  • Uses XML format

  • Follows strict standards

  • Requires WSDL file

It is more structured but heavier than REST.

6. Difference Between SOAP and REST

Feature SOAP REST
Format XML only JSON/XML
Speed Slower Faster
Structure Strict Flexible
Security High Moderate
Complexity Complex Simple

REST is more commonly used today.

7. What Integration Options Are Available in Salesforce?

Salesforce supports many integration methods:

  • REST API

  • SOAP API

  • Bulk API

  • Streaming API

  • Platform Events

  • Change Data Capture

  • Outbound Messages

  • External Services

  • Salesforce Connect

Each method depends on your use case.

8. What Is WSDL?

WSDL stands for Web Services Description Language.

It is an XML file that describes:

  • Service endpoint

  • Methods available

  • Input/output structure

It is used mainly in SOAP integrations.

9. What Is SoapUI?

SoapUI is a tool used to test SOAP and REST APIs.

Developers use it to:

  • Test WSDL

  • Validate responses

  • Debug integrations

10. Difference Between Enterprise WSDL and Partner WSDL

Enterprise WSDL:

  • Strongly typed

  • Specific to one Salesforce org

  • Schema fixed

Partner WSDL:

  • Loosely typed

  • Dynamic

  • Can work with multiple orgs

Enterprise WSDL is simpler.
Partner WSDL is more flexible.

11. What Is an Integration Pattern?

An integration pattern is a design approach that defines how systems communicate.

It helps solve:

  • Data sync

  • Real-time communication

  • Batch processing

  • Event-driven messaging

12. Types of Integration Patterns in Salesforce

Common patterns include:

  1. Remote Process Invocation (Request-Reply)

  2. Fire and Forget

  3. Batch Data Synchronization

  4. Remote Call-In

  5. Event-Driven Architecture

Choosing the right pattern depends on business needs.

13. What Is Remote Site Settings?

Remote Site Settings allow Salesforce to make callouts to external systems.

Without adding the endpoint URL in Remote Site Settings, Salesforce blocks the callout for security reasons.

14. What Is a Connected App?

A Connected App allows external applications to connect to Salesforce using APIs.

It manages:

  • OAuth settings

  • API access permissions

  • Callback URLs

Connected Apps are required for OAuth authentication.

15. What Is OAuth?

OAuth is an authentication protocol.

It allows:
Users to grant access to applications without sharing passwords.

It uses:

  • Access token

  • Refresh token

16. OAuth 2.0 Flows in Salesforce

Salesforce supports multiple OAuth flows:

  1. Authorization Code Flow

  2. Username-Password Flow

  3. JWT Bearer Flow

  4. Web Server Flow

  5. Device Flow

Each flow is used based on use case.

17. What Is JWT Flow in Salesforce?

JWT (JSON Web Token) flow is used for server-to-server integration.

It:

  • Uses digital signature

  • No user interaction required

  • More secure than username-password flow

Commonly used in backend integrations.

18. What Is Web Server Flow?

Web Server Flow is used when:

  • User logs into external app

  • Redirects to Salesforce login

  • Returns with authorization code

Used in web applications.

19. What Is Named Credentials?

Named Credentials store:

  • Endpoint URL

  • Authentication details

Benefits:

  • No hardcoded credentials in Apex

  • Secure

  • Easy maintenance

Highly recommended for callouts.

20. What Is OpenID Connect?

OpenID Connect is built on top of OAuth 2.0.

OAuth = Authorization
OpenID Connect = Authentication

It verifies user identity.

21. Difference Between OpenID and OAuth

OAuth:

  • Grants access

  • No identity confirmation

OpenID:

  • Authenticates user identity

22. What Is Streaming API?

Streaming API allows real-time notifications.

It supports:

  • PushTopic

  • Generic Events

  • Platform Events

  • Change Data Capture

Used for real-time data updates.

23. What Is Change Data Capture?

Change Data Capture (CDC) sends event notifications whenever:

  • Record is created

  • Updated

  • Deleted

Used for real-time data synchronization.

24. What Is Tooling API?

Tooling API is used to manage Salesforce metadata programmatically.

Example:
You can retrieve Apex classes or validation rules.

I used Tooling API to fetch Apex code dynamically for deployment validation.

25. What Is Salesforce Connect?

Salesforce Connect allows real-time access to external data without storing it in Salesforce.

Uses:

  • External Objects

  • OData protocol

Best for large external datasets.

26. What Are REST API Composite Resources?

Composite resources allow:

  • Multiple REST API calls

  • In one single request

Improves performance and reduces API calls.

27. Difference Between API Gateway and ESB

API Gateway:

  • Manages API traffic

  • Security, throttling

  • Request routing

ESB (Enterprise Service Bus):

  • Complex message transformation

  • Orchestration

  • Enterprise-level integration

28. What Is API Gateway?

API Gateway acts as a front door for APIs.

It:

  • Handles authentication

  • Controls traffic

  • Monitors usage

Example: Rate limiting APIs.

29. What Is Middleware (App Glue) in Enterprise Context?

Middleware connects multiple systems.

Examples:

  • MuleSoft

  • Dell Boomi

  • Informatica

It handles:

  • Data transformation

  • Routing

  • Orchestration

  • Error handling

In large enterprises, middleware is critical for scalable architecture.

Final Interview Tips

When answering integration questions:

  • Explain in simple language

  • Give real project example

  • Mention use case

  • Highlight security considerations

  • Discuss error handling

Integration interviews test your architectural thinking, not just definitions.

Leave a Comment

Your email address will not be published. Required fields are marked *