100+ Senior Developer Interview Questions and Answers

Current CTC is confidential. Expectation is based on market standards and my experience.

• Current CTC is confidential information and not disclosed in interviews.

• Expected CTC is based on market standards, industry trends, and my experience.

• I am looking for a competitive salary package that aligns with my skills and expertise.

To delete duplicate rows based on key in a table, use the DELETE statement with a subquery.

• Identify the key column(s) that define the uniqueness of a row

• Use the GROUP BY clause to group the rows by the key column(s)

• Use the HAVING clause to filter out the groups that have more than one row

• Use the subquery to select the duplicate rows to be deleted

• Use the DELETE statement with the subquery to delete the duplicate rows

Data retrieval steps in Informatica ETL process

• Identify the source data to be extracted

• Create source and target connections in Informatica

• Design mappings to extract, transform, and load data

• Use transformations like Filter, Joiner, Lookup, etc.

• Run the ETL job to retrieve data from source to target

In exception handling, parent catch blocks should be placed after child catch blocks to ensure proper error handling.

• Catch blocks are evaluated in the order they are written; the first matching block executes.

• If a child catch block is placed before a parent, the parent block will never execute for that exception type.

• Example: If 'catch (Exception e)' is before 'catch (SpecificException e)', the specific exception will be caught by the general one.

• Best practice is to order cat...read more

Create a Serverless function to expose CRUD operations using DynamoDB

• Use AWS Lambda to create the Serverless function

• Use API Gateway to expose the API endpoints

• Use AWS SDK to interact with DynamoDB for CRUD operations

• Implement GET, POST, PUT, DELETE methods for CRUD operations

SCDs are used to track changes in data over time. There are three types: Type 1, Type 2, and Type 3.

• Type 1 SCDs overwrite old data with new data.

• Type 2 SCDs add a new row for each change, with a start and end date.

• Type 3 SCDs add columns to the existing row to track changes.

• SCDs are commonly used in data warehousing and business intelligence.

• The choice of SCD type depends on the specific use case and data requirements.

Fact and dimension are two types of data in a data warehouse.

• Fact is a measurable event that can be analyzed, while dimension provides context to the fact.

• Fact is quantitative, while dimension is qualitative.

• Fact is stored in a fact table, while dimension is stored in a dimension table.

• Examples of fact include sales, revenue, and profit, while examples of dimension include time, location, and product.

• Fact and dimension are used in data modeling to create a star schema or snow...read more

To bind a gateway to a serverless function, you can use API Gateway services provided by cloud providers like AWS, Azure, or Google Cloud.

• Create a new API Gateway in your cloud provider's console.

• Define the API endpoints and methods that will trigger your serverless function.

• Connect the API Gateway to your serverless function by specifying the function's ARN or endpoint.

• Set up any necessary permissions or security configurations for the API Gateway to invoke the function.

• Test...read more

Outer join returns all records from one table and matching records from another, while inner join returns only matching records.

• Outer join uses the (+) symbol in Oracle and LEFT/RIGHT OUTER JOIN in SQL Server

• Inner join uses INNER JOIN keyword in SQL

• Sample data: Table A has 5 records, Table B has 3 records, Outer join returns 8 records while Inner join returns 3 records

I primarily use JUnit and Mockito for unit testing in Java projects.

• JUnit is a popular Java testing framework for writing and running unit tests

• Mockito is a mocking framework that allows for creating mock objects in unit tests

Object-oriented programming concepts in Java, multi-threading, key interfaces and implemented classes in collections, internal working of HashMap, contract of toString() and hashCode() methods, Comparable and Comparator, Spring bean and IOC, Spring Boot annotations, microservices and design patterns.

• OOPs concepts in Java include encapsulation, inheritance, polymorphism, and abstraction.

• Multi-threading life cycle involves states like new, runnable, running, blocked, and termin...read more

To find the difference between two dates, subtract the earlier date from the later date.

• Subtract the earlier date from the later date

• Use a date library or built-in functions to perform the subtraction

• Consider time zones and daylight saving time if applicable

I follow agile methodology and use version control systems like Git. I also prioritize testing and documentation.

• I follow agile methodology for software development

• I use version control systems like Git to manage code changes

• I prioritize testing and documentation throughout the development process

• I regularly review and refactor code to ensure maintainability

• I collaborate with team members and stakeholders to ensure project success

SonarQube is a tool for continuous inspection of code quality, helping teams identify and fix issues early.

• SonarQube analyzes code for bugs, vulnerabilities, and code smells, improving overall code quality.

• It provides metrics like code coverage, duplications, and complexity, enabling better decision-making.

• Recent improvements may include enhanced detection of security vulnerabilities, such as SQL injection risks.

• Integration with CI/CD pipelines allows for automated quality ch...read more

Mulesoft is an integration platform that connects applications, data, and devices.

• Munit is a testing framework for Mulesoft applications.

• Runtime Manager is a cloud-based platform for managing Mulesoft applications.

• Scaling refers to the ability of Mulesoft to handle increased traffic and workload.

• RAML is a language used to define APIs in a human-readable format.

Degenerate dimension refers to a dimension with only one value.

• A degenerate dimension is a dimension table with only one column and one row.

• It is used to join fact tables with different granularity levels.

• For example, a time dimension with only one value can be used to join a sales fact table with daily granularity and a returns fact table with hourly granularity.

I have used Airflow and Oozie for scheduling ETL jobs.

• Airflow provides a user-friendly UI and supports multiple languages.

• Oozie is good for Hadoop-based ETL jobs and has a web console for monitoring.

• Airflow has a larger community and more plugins available.

• Oozie has better integration with Hadoop ecosystem tools.

• Both are open-source and can handle complex workflows.

I have worked on various connectors including REST, SOAP, JDBC, and JMS.

• I have experience working with REST APIs and building RESTful web services.

• I have worked with SOAP APIs and have experience in creating SOAP-based web services.

• I have worked with JDBC connectors and have experience in connecting to databases using JDBC drivers.

• I have experience working with JMS and have implemented messaging systems using JMS.

• I have also worked with other connectors such as FTP, SFTP, and...read more

Project configuration in .NET without config files

• Use code-based configuration instead of XML configuration

• Create a custom configuration provider

• Use environment variables or command line arguments

• Use a database or other external storage for configuration data

Optimizing website performance with 1000 records in a grid

• Use server-side pagination to limit the number of records fetched at once

• Implement lazy loading to load data only when needed

• Optimize database queries to fetch only necessary data

• Minimize network requests by combining multiple API calls into one

• Use caching mechanisms to store frequently accessed data

Memory leaks occur when unused memory is not released, leading to performance issues. In JS, they can be caused by circular references or event listeners.

• Memory leaks in JS can be caused by circular references, where objects reference each other but are no longer needed.

• Event listeners can also cause memory leaks if not properly removed when no longer needed.

• To deal with memory leaks in JS, it is important to properly manage memory by removing unused references and event list...read more

To run a Java program using command line, use the 'java' command followed by the name of the class containing the main method.

• Navigate to the directory containing the .class file

• Type 'java' followed by the name of the class containing the main method

• Include any necessary command line arguments after the class name

• Press enter to run the program

• Example: java MyProgram arg1 arg2

Add two linked lists representing numbers and return the resulting linked list.

• Traverse both linked lists and add the corresponding digits, keeping track of carry.

• Create a new node for each digit and update the carry for the next iteration.

• If one list is longer than the other, add the remaining digits to the result.

• Handle the case where the carry is not zero after all digits have been added.

• Time complexity: O(max(m,n)), where m and n are the lengths of the input lists.

Create a function in JavaScript to check if a substring in an array can be split into two parts with equal sum.

• Iterate through the array and calculate the total sum of all elements.

• Iterate through the array again and check if there is a point where the sum of elements on the left side is equal to the sum of elements on the right side.

• Return true if such a point is found, otherwise return false.

Full stack development encompasses both front-end and back-end technologies, while Python programming focuses on the Python language itself.

• Full Stack Development: Involves working on both client-side (front-end) and server-side (back-end) technologies, e.g., HTML/CSS/JavaScript for front-end and Node.js/Python for back-end.

• Python Programming: Refers specifically to writing code in Python, which can be used for various applications like web development, data analysis, and aut...read more

To reverse a string in Unix, you can use the 'rev' command.

• Use the 'rev' command followed by the string you want to reverse.

• The 'rev' command reads the input from right to left and outputs it in reverse order.

• The 'rev' command can be used with pipes to reverse the output of other commands.

Managed code is executed by the .NET runtime, while unmanaged code is executed by the operating system.

• Managed code is compiled into an intermediate language (IL) that is executed by the .NET runtime.

• Unmanaged code is compiled into machine code that is executed directly by the operating system.

• Managed code provides automatic memory management, while unmanaged code requires manual memory management.

• Examples of managed code include C# and VB.NET, while examples of unmanaged cod...read more