Photon Interactive Node JS Developer Interview Questions and Answers

Find the length of the longest subsequence of contiguous integers in an array.

• Sort the array

• Iterate through the array and check for consecutive integers

• Keep track of the longest subsequence found

Use flatMap and map to extract list of pincodes from Employee objects

• Use flatMap to flatten the list of Addresses in each Employee object

• Use map to iterate over the flattened list and extract the pincodes

• Example: employeeList.stream().flatMap(emp -> emp.getAddresses().stream()).map(address -> address.getPincode()).collect(Collectors.toList())

Database pooling is a technique used to manage a pool of database connections for efficient resource utilization. HikariCP is a popular database connection pooling library in Java.

• HikariCP is a high-performance database connection pooling library for Java applications.

• It is known for its low latency and high throughput.

• Configurations for HikariCP include settings such as maximum pool size, connection timeout, and idle ...read more

LMS stands for Learning Management System, a software application for the administration, documentation, tracking, reporting, and delivery of educational courses or training programs.

• LMS helps organizations deliver online courses and training programs to employees or students.

• It allows for the creation and management of courses, assessments, and learning materials.

• LMS can track learner progress, generate reports, and p...read more

Shadow DOM is a way to encapsulate the styling and structure of a web component, preventing styles from leaking out or clashing with the rest of the page.

• Shadow DOM allows for creating self-contained components with their own styles and markup

• It helps in preventing styles from the main document affecting the component and vice versa

• Shadow DOM can be created using the 'shadowRoot' property of an element

Some common exceptions in Salesforce development include DMLException, QueryException, and LimitException.

• DMLException: Thrown when an error occurs while performing DML operations like insert, update, delete.

• QueryException: Thrown when an error occurs while querying data from the database.

• LimitException: Thrown when governor limits are exceeded, such as SOQL query limit or CPU time limit.

Yes, I have worked on integration in Salesforce development.

• I have experience integrating Salesforce with external systems using REST and SOAP APIs.

• I have worked on integrating Salesforce with third-party applications like MailChimp and DocuSign.

• I have implemented custom integrations using tools like Salesforce Connect and MuleSoft.

• I have experience with data mapping, transformation, and synchronization during integrat

Governor limits are in place to ensure efficient use of resources and prevent abuse in Salesforce platform.

• Governor limits help in maintaining system performance and preventing monopolization of resources.

• They ensure fair usage of resources among all users on the platform.

• Examples include limits on number of records retrieved in a single query, number of SOQL queries executed, and CPU time consumed.

• Governor limits also...read more

One challenge I faced was integrating a third-party API with Salesforce.

• Had to understand the API documentation thoroughly

• Encountered compatibility issues with Salesforce platform

• Implemented custom code to bridge the gap between API and Salesforce

I contributed by developing new features and fixing bugs. Faced challenges with integrating third-party APIs.

• Developed new features such as user authentication and data visualization

• Fixed bugs related to database queries and UI responsiveness

• Challenges faced with integrating third-party APIs like payment gateways and social media platforms

Design and code a REST API for a software developer interview.

• Define the endpoints and HTTP methods for the API (e.g. GET /users, POST /users)

• Implement authentication and authorization mechanisms (e.g. JWT tokens)

• Use proper status codes for responses (e.g. 200 OK, 401 Unauthorized)

• Include error handling and validation for input data

• Document the API using tools like Swagger or OpenAPI

Calculate word frequency using Stream API and lambda expressions

• Use Stream API to convert array of strings to stream

• Use Collectors.groupingBy to group words by their frequency

• Use Collectors.counting to count the occurrences of each word

Annotations in Java provide metadata about a program that can be used by the compiler or at runtime.

• Annotations start with the @ symbol.

• Annotations can be used to provide information to the compiler or to runtime environments.

• Annotations can be used to define custom metadata for classes, methods, fields, etc.

• Annotations can also be used for code generation, documentation, and validation.

• Examples of annotations in Java ...read more

ConcurrentSkipListMap is a concurrent, sorted map implementation in Java.

• ConcurrentSkipListMap is a concurrent version of SkipListMap, which is a sorted map implementation based on skip list data structure.

• It allows multiple threads to access and modify the map concurrently.

• It provides logarithmic time complexity for most operations, making it efficient for concurrent access.

• Example: ConcurrentSkipListMap