Top 30 commonly asked Salesforce Developer interview questions

Governor limits are constraints imposed by Salesforce to prevent resource abuse within a multi-tenant environment. They limit various aspects, such as the number of SOQL queries, DML operations, and callouts in a single transaction.

For example, you can perform up to 100 SOQL queries in one transaction. Knowing such aspects of governor limits is essential for writing efficient and effective code.

Salesforce uses Apex as the server-side language for customization. Apex shares syntax similarities with Java, making it easy for Java Developers. This is why Salesforce Developer trainees go through Java training before learning Apex.

On the front-end side, you have Lightning Web Components, Aura components, and Visualforce, all using HTML, CSS, JavaScript, and Apex. Additionally, Salesforce incorporates Flow, which is a low-code language. It allows Salesforce Developers and Admins to customize on both the front-end and back-end.

The Salesforce data model is a structured representation of how data is organized and related in the Salesforce platform. At its core, Salesforce uses a relational database model, with objects as its fundamental building blocks. 

Objects are equivalent to database tables, and they store different types of data, such as standard objects like “Accounts,” “Contacts,” and custom objects created by users. These objects have fields that store specific data attributes, similar to database columns. 

Fields can be of various data types, such as text, number, date, or lookup to other objects. Relationships between objects are established through fields like “Master-Detail” and “Lookup,” forming the basis for data relationships. 

Understanding the data model is essential for designing effective solutions in Salesforce.

Salesforce declarative customization involves creating custom fields and objects. The tools allow you to define your database schema declaratively and enhance object customization through page layouts and Lightning app pages.

Salesforce encourages the use of Flow for declarative automation, as it's more versatile and upgraded than the now-deprecated Workflow Rules and Process Builder.

Programmatic development is the preferred choice when dealing with complex business requirements and specialized processes, which are either non-feasible or not possible through declarative development.

Additionally, programmatic development is suitable for highly customized user interfaces that match business branding and user experience requirements. It's also essential for optimizing performance, especially with extensive data or complex calculations.

Apex is an object-oriented, strongly typed programming language used in the Salesforce ecosystem. Its syntax is similar to Java. Apex is used to build custom business logic and extend the core capabilities of the Salesforce platform.

Apex is used when Salesforce's declarative tools, such as Workflow Rules, Process Builders, and Flows, are insufficient to meet the business logic. Apex allows Developers to write custom code for complex business requirements. In many cases, it is more efficient than declarative tools.

An Apex trigger is a code that automatically executes before or after a specific data event in Salesforce, such as record insertion, update, or deletion. Triggers are used to perform actions at the database level, ensuring data consistency and integrity.

You should use an Apex trigger when you need to respond to changes in your data, such as updating related records, sending email notifications, or performing complex validations.

Triggers are particularly helpful when declarative tools are insufficient to achieve the desired automation or when advanced customization is required.

Writing efficient and scalable Apex code is crucial in maintaining the Salesforce ecosystem. There are a few best practices that one should follow:

1. Limit the number of SOQL queries and DML statements, and keep track of governor limits.
2. Use trigger bulkification to handle multiple records at once.
3. Implement error handling to avoid issues while running a code.
4. Use asynchronous processing for long-running tasks.
5. Use trigger frameworks to structure the code and make it easy for other Developers to follow.

Asynchronous Apex is used to perform long-running and resource-intensive tasks in the background. Having asynchronous Apex code that doesn’t need to be managed repeatedly frees up the user interface and ensures a responsive user experience.

There are various ways to implement asynchronous processing in Salesforce, such as Batch Apex, Schedulable Apex, and Queueable Apex.

In Salesforce triggers, “trigger.old,” “trigger.new,” and “trigger.newMap” are context variables used to work with records during trigger execution.

• “trigger.old” contains a list of the old versions of records before the trigger was invoked. It's read-only and can track changes by comparing it with new versions.
• “trigger.new” holds a list of the new versions of records that caused the trigger to fire. You can modify these records before they're saved.
• “trigger.newMap” is a map of new records, indexed by their record IDs. It's useful when you need to access or update specific records based on their IDs.

Salesforce provides several debugging options, including:

1. “System.debug():” You can insert debug statements in your code to log information to the debug logs.
2. Developer Console: You can use the Developer Console to monitor logs, set checkpoints, and inspect variables.
3. Apex Replay Debugger: This is a feature in VS Code that lets you step through code execution and examine variables.
4. Checkpoints: Creating checkpoints in your code inspects data at specific points during execution.
5. Exception handling: Implement proper exception handling to capture and handle errors automatically.
6. Debug logs: You can adjust log levels in debug settings for more detailed information.

You can do so by using HTTP callouts. It allows you to invoke external APIs and exchange data in Salesforce with external systems. When integrating with “REST” web services, you should consider the data format, authentication, error handling, rate limiting, and monitoring to prevent integration issues.

Like any other REST API, the Salesforce REST API is a set of resources and methods allowing you to interact with Salesforce objects and data using standard HTTP methods. It is preferable to use the Salesforce REST API in the following scenarios:

• When building web and mobile applications that require real-time access to Salesforce data
• For lightweight integrations with external systems that do not require extensive processing
• When simplicity and flexibility are more important than real-time processing, as the REST API offers an easier way to access data.

There are two common methods for securing credential management in Salesforce:

• Named credentials provide a secure way to store and manage external system credentials. They specify the base endpoint and authentication credentials, allowing Salesforce to handle authentication.
• For cases where named credentials may not be suitable, you can use custom metadata types to store credentials securely. This approach enables different credentials for different environments and access control.

These methods ensure that credentials are not hard-coded in your code, reducing security risks.

The main differences between “SOAP” (simple object access protocol) and “REST” (representational state transfer) include:

1. Protocol and message format: SOAP uses a standardized protocol and XML message format, while REST uses simple HTTP requests with data formats like JSON or XML.
2. Security: SOAP provides built-in security features like WS-Security, making it suitable for applications with stringent security requirements. REST relies on external security mechanisms.
3. Complexity: SOAP is known for its robustness and structure, making it suitable for complex, enterprise-level integrations. REST is simpler and lightweight, making it ideal for simple integrations.
4. Performance: REST is often considered faster and more efficient due to its simplicity and use of HTTP methods.

In short, use SOAP for strong security or when working in an enterprise context and REST for lightweight and performance-oriented integrations.

LWCs are the latest web standard for building custom HTML elements in Salesforce development. LWCs are modern, standards-based, and designed to provide better performance and efficiency.

Unlike Aura components, which use a proprietary framework, LWCs are built on web standards like ECMAScript and HTML. This change makes LWCs more lightweight, faster, and easier to work with.

Lightning Web Components offer a way for Administrators to fine-tune component behavior without coding. Salesforce Administrators can do this by defining design attributes in the component's metadata. These design attributes can be easily configured using the Lightning App Builder. This allows Administrators to adjust component properties, appearance, and behavior as per the requirement.

LWCs uses a publish-subscribe model to enable communication with an application. Components can communicate through custom events – one component emits an event, and others can listen and respond accordingly. This approach keeps components loosely coupled, promoting modularity and reusability in your application.

The SLDS is a framework developed to maintain a consistent and visually appealing user interface design for applications built on the Salesforce Lightning Platform.

SLDS includes a wide array of resources, such as CSS styles, design patterns, components, and guidelines for building applications that enhance the Lightning user experience. It not only offers a unified look and feel but also prioritizes accessibility, responsiveness, and a user-friendly design.

Salesforce Developers use SLDS to ensure that their custom Lightning Components and applications align with the core Salesforce design principles.

Lightning Components can be used for various purposes within the Salesforce ecosystem. Here are the key aspects where you can use Lightning Components:

• Utility bar
• Quick actions
• External web pages
• Flows
• Outlook and Gmail integrations
• Visualforce pages
• Pre-chat snap-ins.

To enforce field-level security in Apex, you can use the “WITH SECURITY_ENFORCED” clause in your SOQL queries. This clause is essential for preventing unauthorized access to fields. If the permissions for the requested fields are missing, this clause throws an insufficient permission exception.

Enforcing sharing rules extends record access beyond the default settings. You can enforce different types of sharing rules (criteria-based and ownership-based) and their effect on data access. It is best to always consider the security model in the context of your application's requirements.

Bypassing sharing rules and FLS is only necessary for system-level processes or specific actions requiring it. When doing so, you should ensure the bypassing rules offer minimal exposure.

One best practice is to isolate these actions into separate classes or methods, maintaining strict control over where and how security rules are bypassed. This prevents unintentional data exposure and strengthens your application's security.

When working with dynamic SOQL queries that take user input, it is important to sanitize that input to prevent SQL injection attacks. Also, ensure all user-provided values are correctly escaped – primarily single quotes – to prevent unauthorized data access or manipulation.

Use bind variables to safeguard dynamic values in your queries whenever possible. This helps protect your application against injection attacks while allowing flexibility in your queries.

Debugging security issues involves analyzing debug logs, monitoring exceptions, and staying informed about security updates. Optimize security by proactively identifying and mitigating potential vulnerabilities and threats. Review and update your security controls regularly, and consider periodic security assessments.

To enforce security in Lightning Web Components, you can use Locker Service, which restricts access to the DOM and other sensitive resources. It also helps prevent cross-site scripting (XSS) attacks.

In configuration tasks, ensure that LWCs follow security best practices by utilizing Locker Service features. This safeguards your application against security risks, providing a more robust and secure user experience.

A roll-up summary field calculates values from related records in a master-detail relationship. It is commonly used to summarize data from child records and display it on the master record. For example, you can use a roll-up summary field to calculate the total revenue from all related opportunities on an account. This simplifies reporting and ensures data consistency.

Dynamic Apex allows Developers to access and manipulate sObjects and fields dynamically rather than declaratively. In configuration tasks, Dynamic Apex can be used to create flexible and reusable solutions. For instance, you can build dynamic SOQL queries to retrieve data based on runtime criteria, offering greater flexibility in data retrieval without hardcoding field names.

Custom metadata types allow Salesforce Developers to create custom metadata that can be used in a Salesforce application. Unlike custom objects, custom metadata is customizable at runtime and is ideal for storing configuration data.

For example, you can use custom metadata types to define various approval processes for different record types. This makes it easy to modify these approval processes without altering the underlying code.

Named credentials provide a secure way to store external service credentials. In configuration, named credentials are beneficial when setting up integrations with external systems. They abstract the authentication process and enable secure access to external services.

For example, when configuring an outbound integration to call a REST API, named credentials can store the API endpoint and associated authentication credentials.