60+ Application Developer Interview Questions and Answers for Freshers

The game is not fair.

• Player X has a higher chance of winning as they only need to get a consecutive HEAD, TAIL.

• Player Y needs to get a consecutive HEAD, HEAD which is less likely to occur.

• The probability of Player X winning is higher than Player Y winning.

The last ball that will be left is black.

• When you take out 2 black balls, you take another white ball.

• If you take 2 white balls, you take out 1 black ball.

• If balls are of different color, you take out another black ball.

• Since there are more black balls initially, the last ball will be black.

Generate a tree structure from CSV values with a maximum height of 3, ensuring proper hierarchy.

• Read the CSV file line by line to extract values like E1:12, E2:32.

• Create a root node 'E' and add child nodes based on the extracted values.

• For each child node (e.g., E1), create its children (e.g., E11, E12) based on the specified count.

• Ensure that if E1 is not present, its children (E11, E12) are not included.

• Example: If CSV has E1:2, E2:3, then E1 will have E11, E12 and E2 will ...read more

tmap is used to transform data in Talend, tjoin is used to join data. There are different types of connections, truncate and delete are different ways to remove data from a table. ETL stands for Extract, Transform, Load. Triggers are database objects that are automatically executed in response to certain events. There are different types of joins.

• tmap is used for data transformation in Talend

• tjoin is used for joining data in Talend

• Types of connections include database connect...read more

The program prints the substring after a specified character has occurred a certain number of times in a given string.

• Iterate through the string to find the specified character.

• Keep track of the count of occurrences of the character.

• Once the count reaches the specified count, extract the substring after that position.

• Handle corner cases such as when the character is not in the string or when it doesn't occur the specified number of times.

Print all possible paths from start to end in a linear way, moving either one or two steps right.

• Use dynamic programming to solve the problem

• Create a 2D array to store the number of paths to each position

• Start from the end position and work backwards

• At each position, calculate the number of paths by summing the number of paths from the next two positions

• Print all the paths by backtracking from the start position

The words in a string can be arranged based on their order of occurrence.

• Split the string into an array of words

• Create a dictionary to store the count of each word

• Sort the array based on the count of each word

• Join the sorted array back into a string

Interview questions for application developer including Python applications, PEP8, CSS, input handling, list vs tuples, and willingness to relocate.

• Python is used for web development, data analysis, machine learning, and more

• PEP8 is a style guide for Python code

• CSS stands for Cascading Style Sheets and is used for styling web pages

• To find input3, use input3 = input1 + input2

• To resolve issues with colleagues, communicate and collaborate effectively

• Lists and tuples are both use...read more

The code inserts two numbers in a text file, ensuring that the second number is greater than the first and there is no overlap between entries.

• Read the existing entries from the text file

• Check if the new numbers satisfy the conditions

• If conditions are met, insert the new numbers into the file

• Otherwise, display an error message

This C program reverses the order of words in a given string while preserving the characters within each word.

• 1. Split the string into words using space as a delimiter. Example: 'Oracle @ App Dev' -> ['Oracle', '@', 'App', 'Dev']

• 2. Reverse the array of words. Example: ['Oracle', '@', 'App', 'Dev'] -> ['Dev', 'App', '@', 'Oracle']

• 3. Join the reversed array back into a single string with spaces. Example: 'Dev App @ Oracle'

The code prints the transpose of a given matrix.

• Iterate through each row and column of the matrix.

• Swap the elements at the current row and column with the elements at the current column and row.

• Print the transposed matrix.

Code to count the number of times '1' occurs from 1 to 999999

• Loop through all numbers from 1 to 999999

• Convert each number to a string and count the number of '1's in it

• Add the count to a running total

• Return the total count

Code to find the middle element of a linked list

• Traverse the linked list with two pointers, one moving twice as fast as the other

• When the fast pointer reaches the end, the slow pointer will be at the middle element

• If the linked list has even number of elements, return the second middle element

Python is a versatile and powerful programming language known for its simplicity and readability.

• Python has a simple and easy-to-understand syntax, making it beginner-friendly.

• It has a large standard library with built-in modules for various tasks, reducing the need for external dependencies.

• Python supports multiple programming paradigms, including procedural, object-oriented, and functional programming.

• It has excellent community support with a vast number of libraries and fr...read more

Arrange 4 coins to make maximum number of triangles

• Place 3 coins in a triangle formation and the fourth coin in the center to form 4 triangles

• Place 2 coins on top of each other and the other 2 coins on either side to form 2 triangles

• Place 2 coins in a line and the other 2 coins on either side to form 2 triangles

I will prioritize urgent client or user pings and respond promptly to address their needs.

• Prioritize urgent client or user pings over non-urgent ones

• Respond promptly to address their needs

• Communicate with the client or user to understand the issue and provide assistance

• Document the issue and resolution for future reference

Talend is popular due to its open-source nature, ease of use, and ability to integrate with various systems.

• Talend is open-source, making it accessible to a wide range of users.

• It has a user-friendly interface, allowing developers to easily create and manage data integration workflows.

• Talend can integrate with various systems, including cloud-based platforms like AWS and Azure.

• It offers a wide range of connectors and components, making it versatile and adaptable to different ...read more

Arrange 10 coins in 4 rows of 4 coins each.

• Place 4 coins in a row and keep the remaining 6 aside.

• Place 3 coins from the remaining 6 in the next row and keep the remaining 3 aside.

• Place 2 coins from the remaining 3 in the third row and keep the remaining 1 aside.

• Place the last coin in the fourth row along with the remaining 1 coin from step 3.

• The final arrangement will have 4 rows with 4 coins each.

Indexes used include bitmap and btree. Bitmap index is used for low cardinality columns, while btree index is used for high cardinality columns.

• Bitmap index is efficient for low cardinality columns with few distinct values

• Btree index is efficient for high cardinality columns with many distinct values

• Bitmap index uses bitmaps to represent the presence of a value in a column

• Btree index is a balanced tree structure that allows for fast searching and retrieval of data

Frontend is the part of a website or application that users interact with, while backend is the part that handles the behind-the-scenes functionality.

• Frontend is responsible for the user interface and user experience.

• Backend is responsible for server-side logic, database operations, and other behind-the-scenes tasks.

• Frontend technologies include HTML, CSS, and JavaScript.

• Backend technologies include languages like Java, Python, and frameworks like Node.js.

• Examples: Frontend -...read more

Talend is an ETL tool used for data integration. Jobs are workflows created in Talend to perform specific tasks. Components are pre-built functions used in jobs.

• Jobs are created in Talend to perform specific tasks such as data extraction, transformation, and loading.

• Components are pre-built functions that can be used in jobs to perform specific actions such as reading data from a file or database, transforming data, and writing data to a file or database.

• Talend provides a wid...read more

The app development life cycle includes planning, design, development, testing, deployment, and maintenance phases.

• Planning: Defined the app's purpose, target audience, and key features through brainstorming sessions and market research.

• Design: Created wireframes and prototypes using tools like Figma to visualize the user interface and user experience.

• Development: Utilized Agile methodology, breaking the project into sprints, and implemented features using technologies like R...read more

To ensure a great user experience, I focus on usability, performance, accessibility, and continuous feedback from users.

• User-Centered Design: I conduct user research and usability testing to understand user needs and preferences, ensuring the app meets their expectations.

• Responsive Design: I implement responsive layouts that adapt to various screen sizes and devices, providing a seamless experience across platforms.

• Performance Optimization: I optimize loading times and respon...read more

Post-launch, I focus on monitoring, profiling, and iterative improvements to ensure optimal app performance and effective debugging.

• Monitoring Tools: Utilize tools like New Relic or Google Analytics to track app performance metrics such as load times and user interactions.

• Profiling: Use profiling tools like Chrome DevTools to identify bottlenecks in the code, such as slow functions or excessive re-renders.

• Error Tracking: Implement error tracking services like Sentry to captur...read more

Procedures do not return a value, while functions return a value.

• Procedures are used to perform an action, while functions are used to calculate and return a value.

• Functions must return a value, while procedures do not have a return statement.

• Functions can be called from within SQL statements, while procedures cannot.

• Example: Procedure - void PrintMessage(string message) { Console.WriteLine(message); }

• Example: Function - int AddNumbers(int a, int b) { return a + b; }

Manageable code is well-structured, organized, and easy to maintain, while unmanageable code is messy, hard to understand, and prone to errors.

• Manageable code follows best practices and design patterns, making it easier to read and maintain.

• Unmanageable code lacks structure, consistency, and documentation, making it difficult to work with.

• Examples of manageable code include well-commented classes and methods, consistent naming conventions, and modular architecture.

• Examples of...read more

Multitasking is the ability of an operating system to run multiple tasks concurrently while multiprogramming is the ability to run multiple programs concurrently.

• Multitasking allows multiple tasks to run concurrently on a single processor system.

• Multiprogramming allows multiple programs to run concurrently on a single processor system.

• Multitasking is achieved through time-sharing, where the processor switches between tasks at a very high speed.

• Multiprogramming is achieved thr...read more

Query to find 3rd highest salary from each department

• Use window functions like ROW_NUMBER() to rank salaries within each department

• Filter the results to only include rows where the rank is 3

• Group by department to get the 3rd highest salary for each department

Inner join returns only the matching records from both tables, while outer join returns all records from both tables.

• Inner join combines rows from two tables based on a related column.

• Outer join combines rows from two tables, including unmatched rows.

• Inner join returns only the matching records from both tables.

• Outer join returns all records from both tables, filling in NULL values for unmatched rows.

• Example: Inner join of 'Customers' and 'Orders' tables will return only the ...read more

Quality testing is performed to ensure that software meets the required standards and functions correctly.

• Quality testing involves various techniques such as functional testing, performance testing, security testing, and usability testing.

• Functional testing checks if the software meets the specified requirements.

• Performance testing evaluates the software's speed, scalability, and stability under different conditions.

• Security testing identifies vulnerabilities and ensures data...read more

To add a 20% discount code and implement cashback in an application.

• Create a discount code field in the application where users can enter the code to avail 20% off.

• Calculate the discounted price by applying the 20% discount on the original price.

• Implement a cashback feature where users receive a certain percentage of the purchase amount back as cashback.

• Ensure that the cashback amount is credited to the user's account after the purchase is completed.

Answers to questions related to application development

• String is immutable because it cannot be changed once created. Any modification creates a new object.

• Arrays are fixed in size while ArrayLists can dynamically grow and shrink.

• OOP concepts include encapsulation, inheritance, and polymorphism.

• SQL queries are used to retrieve, insert, update, and delete data from a database.

Circular doubly linked list is a data structure where each node has a reference to both the next and previous nodes, forming a circular loop.

• Create a Node class with data, next, and prev pointers

• Implement operations like insert, delete, search, and display

• Ensure the last node's next pointer points to the first node and the first node's prev pointer points to the last node

Searching and sorting algorithms are essential in programming for efficiently organizing and retrieving data.

• Searching algorithms: linear search, binary search, depth-first search, breadth-first search

• Sorting algorithms: bubble sort, selection sort, insertion sort, merge sort, quick sort

• Examples: Searching for a specific item in a list, sorting a list of numbers in ascending order

Spring created via literal is created using curly braces with key-value pairs, while spring created via object is created using a constructor function.

• Spring created via literal: var spring = { color: 'blue', length: 10 };

• Spring created via object: function Spring(color, length) { this.color = color; this.length = length; }

Program to remove duplicates in a string

• Create an empty array to store unique characters

• Iterate through each character in the string

• Check if the character is already in the array, if not add it

SMPS stands for Switched-Mode Power Supply.

• It is an electronic power supply that uses a switching regulator to convert electrical power efficiently.

• It is commonly used in computers, TVs, and other electronic devices.

• It is smaller and lighter than traditional linear power supplies.

• It can operate at high frequencies, reducing the size of transformers and capacitors.

• It is more energy-efficient than linear power supplies.

• Examples include the Mean Well LRS-350-12 and the Delta Ele...read more

To compare 2 files in file handling, read both files line by line and compare each line.

• Read both files line by line

• Compare each line of the files

• Handle cases where files have different number of lines

• Use file handling functions like fopen, fgets, and fclose

Talend and Pentaho are both open-source data integration tools, but Talend is more user-friendly while Pentaho has better reporting capabilities.

• Talend has a drag-and-drop interface and a large library of pre-built components, making it easier for non-technical users to create data integration workflows.

• Pentaho has a more robust reporting engine and better visualization capabilities, making it a better choice for business intelligence and analytics.

• Both tools support a wide r...read more

To deactivate a trigger in production, you can use the ALTER TRIGGER statement to disable the trigger.

• Use the ALTER TRIGGER statement with the DISABLE option to deactivate the trigger.

• Make sure to test the trigger deactivation in a non-production environment before applying it to production.

• Document the trigger deactivation process for future reference and troubleshooting.

Abstraction focuses on hiding the implementation details, encapsulation bundles data and methods together, and interfaces define a contract for classes to implement.

• Abstraction: Hides the implementation details and only shows the necessary features. Example: Car class with start() and stop() methods without showing the internal engine workings.

• Encapsulation: Bundles data and methods together within a class, preventing direct access from outside. Example: Private variables wit...read more

Python is used for data science due to its simplicity, readability, extensive libraries, and community support.

• Python is easy to learn and read, making it accessible for beginners and experts alike

• Python has a wide range of libraries like NumPy, Pandas, and Scikit-learn for data manipulation and analysis

• Python has a strong community support with active forums and resources for data science enthusiasts

• Python's versatility allows for integration with other tools and languages c...read more

AWS offers a wide range of cloud services for various purposes.

• Compute services: EC2, Lambda

• Storage services: S3, EBS

• Database services: RDS, DynamoDB

• Networking services: VPC, Route 53

• Security services: IAM, KMS

• Analytics services: Redshift, EMR

• AI/ML services: SageMaker, Rekognition

Tcode for BADI is SE18. To find a BADI, use transaction code SE18 and enter the BADI name or filter by application area.

• Tcode for BADI is SE18

• To find a BADI, use transaction code SE18

• Enter the BADI name or filter by application area

Encapsulation focuses on hiding the internal state of an object and restricting access to it, while polymorphism allows objects of different classes to be treated as objects of a common superclass.

• Encapsulation helps in achieving data hiding and abstraction by restricting access to certain components of an object.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass, enabling flexibility and extensibility in code.

• Encapsulation is imp...read more

Lambda function is an anonymous function in Python that can have any number of arguments, but can only have one expression.

• Lambda functions are defined using the lambda keyword.

• They are commonly used for small, one-time operations.

• Lambda functions can be used as arguments to higher-order functions like map, filter, and reduce.

• Example: add = lambda x, y: x + y

HashSet provides constant time performance for basic operations like add, remove, contains, while ArrayList does not.

• HashSet does not allow duplicate elements, while ArrayList allows duplicates.

• HashSet does not maintain insertion order, while ArrayList maintains insertion order.

• HashSet is faster for checking if an element exists (contains) compared to ArrayList.