100+ Divyadrishti Eye Centre Interview Questions and Answers

Slowly changing dimensions refer to data warehouse dimensions that change slowly over time.

• SCDs are used to track historical changes in data over time.

• There are three types of SCDs - Type 1, Type 2, and Type 3.

• Type 1 SCDs overwrite old data with new data, Type 2 creates new records for changes, and Type 3 maintains both old and new data in separate columns.

• Example: A customer's address changing would be a Type 2 SCD.

• Example: A product's price changing would be a Type 1 SCD.

Major financial statements include income statement, balance sheet, and cash flow statement, which are interconnected through net income and retained earnings.

• Income statement shows revenues and expenses, resulting in net income.

• Balance sheet displays assets, liabilities, and equity, with net income affecting retained earnings.

• Cash flow statement details cash inflows and outflows, reconciling with changes in cash on the balance sheet.

• Net income from the income statement flows...read more

To create a workflow in Databricks, use Databricks Jobs or Databricks Notebooks with scheduling capabilities.

• Use Databricks Jobs to create and schedule workflows in Databricks.

• Utilize Databricks Notebooks to define the workflow steps and dependencies.

• Leverage Databricks Jobs API for programmatic workflow creation and management.

• Use Databricks Jobs UI to visually design and schedule workflows.

• Integrate with Databricks Delta for optimized data processing and storage.

Singleton class is a class that can only have one instance and provides a global point of access to it.

• Singleton class restricts the instantiation of a class to one object.

• It provides a way to access its unique instance globally.

• Commonly used in scenarios where only one instance of a class is needed, such as database connections or thread pools.

To ensure high availability of EKS cluster, utilize multiple availability zones, implement auto-scaling, use managed node groups, and set up monitoring and alerts.

• Utilize multiple availability zones to distribute workload and ensure redundancy.

• Implement auto-scaling to automatically adjust resources based on demand.

• Use managed node groups to simplify node management and ensure high availability.

• Set up monitoring and alerts to quickly identify and address any issues that may i...read more

DNS is a system that translates domain names to IP addresses, allowing users to access websites using human-readable names.

• DNS stands for Domain Name System

• It helps in translating domain names to IP addresses

• DNS servers store a database of domain names and their corresponding IP addresses

• DNS plays a crucial role in enabling users to access websites using human-readable names instead of IP addresses

Encapsulation is the process of hiding implementation details and restricting access to an object's data and methods.

• Encapsulation helps in achieving data abstraction and security.

• It allows for better control over the data and prevents accidental modification.

• It also enables easy modification of implementation details without affecting the rest of the code.

• For example, a class can have private variables and public methods to access and modify them.

To create slice and combine reducers in React, use the createSlice and combineReducers functions from Redux toolkit.

• Use createSlice function to define a slice of state with reducers and actions.

• Example: const counterSlice = createSlice({ name: 'counter', initialState: 0, reducers: { increment: state => state + 1, decrement: state => state - 1 } })

• Use combineReducers function to combine multiple slices into a single root reducer.

• Example: const rootReducer = combineReducers({ c...read more

Java 8 is a major release of the Java programming language with new features like lambda expressions, streams, and default methods.

• Lambda expressions allow you to treat functionality as a method argument.

• Streams provide a new abstraction to work with sequences of elements.

• Default methods allow interfaces to have method implementations.

• Date and Time API provides a new way to work with dates and times.

• Optional class helps to avoid null pointer exceptions.

Dependency injection is a design pattern that allows objects to receive dependencies rather than creating them internally.

• Dependency injection helps to decouple components and make them more modular and testable.

• It allows for easier maintenance and scalability of code.

• There are three types of dependency injection: constructor injection, setter injection, and interface injection.

• Example: Instead of creating a database connection object within a class, the object is passed in a...read more

Abstraction is the concept of hiding complex details and showing only the essential features of an object or system.

• Abstraction allows us to focus on what an object does, rather than how it does it

• It helps in reducing complexity and improving efficiency in software development

• Example: In a car, we don't need to know the internal workings of the engine to drive it

The total amount of work undertaken is difficult to quantify as it varies depending on the specific tasks and projects being managed.

• The total amount of work can be measured in terms of number of projects completed within a certain time frame.

• It can also be measured in terms of the number of tasks or activities completed by the team.

• The complexity and size of each project or task should also be taken into consideration when calculating the total amount of work undertaken.

To select an element from a drop down, locate the drop down element and use the select class in Selenium.

• Locate the drop down element using findElement() method

• Create an object of Select class using the drop down element

• Use selectByVisibleText(), selectByValue() or selectByIndex() method to select the desired option

Marker interface is an empty interface used to mark classes for special treatment.

• Marker interface has no methods or fields, it is used to provide metadata about the class.

• It is used by frameworks or APIs to identify classes that implement the interface.

• Examples include Serializable interface in Java, which marks classes as serializable.

Performing operations on an array of objects using JavaScript.

• Use array methods like map, filter, reduce for operations on object array.

• Access object properties using dot notation or bracket notation.

• Iterate through the array using loops like for loop or forEach method.

• Example: Calculate total sum of 'price' property in an array of products.

Agile is a methodology that emphasizes flexibility and collaboration. Agile Scrum is a framework for implementing Agile.

• Agile focuses on delivering working software in short iterations

• Agile values individuals and interactions over processes and tools

• Agile encourages customer collaboration and responding to change

• Agile Scrum includes ceremonies such as Sprint Planning, Daily Stand-up, Sprint Review, and Sprint Retrospective

• Sprint Planning involves the team planning the work to...read more

getmetadata is used to retrieve metadata information about a dataset or data source.

• getmetadata can provide information about the structure, format, and properties of the data.

• It can be used to understand the data schema, column names, data types, and any constraints or relationships.

• This information is helpful for data engineers to properly process, transform, and analyze the data.

• For example, getmetadata can be used in data pipelines to dynamically adjust processing logic b...read more

Object-oriented programming concepts that help in organizing and structuring code.

• Encapsulation: Bundling data and methods together in a class.

• Inheritance: Creating new classes from existing ones, inheriting their properties and behaviors.

• Polymorphism: Objects of different classes can be treated as objects of a common superclass.

• Abstraction: Hiding complex implementation details and providing simplified interfaces.

• Encapsulation: Protecting data from unauthorized access by usi...read more

Encapsulation in JavaScript is achieved through the use of closures and modules.

• Encapsulation is the practice of keeping variables and functions private within a class or module.

• Closures allow for private variables and functions to be created within a function.

• Modules are self-contained units of code that can be imported and used in other parts of the application.

• The revealing module pattern is a common way to implement encapsulation in JavaScript.

Microservice architecture with Spring Boot is a popular approach to building scalable and resilient applications.

• Spring Boot provides a convenient way to create and deploy microservices

• Each microservice should have a clear and well-defined responsibility

• Communication between microservices can be achieved through REST APIs or messaging systems like Kafka

• Containerization with Docker and orchestration with Kubernetes can simplify deployment and scaling

• Monitoring and logging are ...read more

Inheritance is a mechanism in OOP where a new class is derived from an existing class.

• It allows the new class to inherit the properties and methods of the existing class.

• Types of inheritance: Single, Multiple, Multilevel, Hierarchical, Hybrid.

• Example: A class 'Car' can inherit from a class 'Vehicle' which has properties like 'speed', 'fuel type', etc.

Liveness and readiness probes are used in Kubernetes to check the health of containers.

• Liveness probe checks if a container is running and healthy. If it fails, Kubernetes restarts the container.

• Readiness probe checks if a container is ready to serve traffic. If it fails, Kubernetes stops sending traffic to the container.

• Probes are configured in the pod's YAML file using the 'livenessProbe' and 'readinessProbe' fields.

• Examples of probes include HTTP requests, TCP socket check...read more

Strengths include strong analytical skills and attention to detail. Weaknesses may include difficulty with public speaking and time management.

• Strengths: strong analytical skills

• Strengths: attention to detail

• Weaknesses: difficulty with public speaking

• Weaknesses: time management

HashMap in Java is a data structure that stores key-value pairs and allows fast retrieval of values based on keys.

• HashMap uses hashing to store key-value pairs in an array of linked lists.

• It allows null keys and values.

• HashMap provides constant-time performance for basic operations like get and put.

• Example: HashMap map = new HashMap<>(); map.put("key1", 1); int value = map.get("key1");

SCD type2 table is used to track historical changes in data by creating new records for each change.

• Contains current and historical data

• New records are created for each change

• Includes effective start and end dates for each record

• Requires additional columns like surrogate keys and version numbers

• Used for slowly changing dimensions in data warehousing

Types of testing for mobile applications include functional testing, performance testing, security testing, usability testing, and compatibility testing.

• Functional testing ensures the app functions as expected

• Performance testing checks the app's speed and responsiveness

• Security testing identifies vulnerabilities and ensures data protection

• Usability testing evaluates user experience and interface design

• Compatibility testing ensures the app works on different devices and operat...read more

I have exposure to healthcare domain.

• Worked as a business analyst for a healthcare company for 2 years.

• Analyzed data related to patient care, insurance claims, and medical billing.

• Familiar with healthcare regulations such as HIPAA and HITECH.

• Collaborated with healthcare professionals to identify process improvements.

• Attended industry conferences and workshops to stay up-to-date on healthcare trends.

Developed a custom Drupal module for creating a custom content type with specific fields and functionality.

• Created a custom module folder within the Drupal installation

• Defined the custom content type and its fields in the module's .info file

• Implemented hook functions to handle data processing and display logic

• Used Drupal's Form API to create custom forms for data input and editing

• Integrated with other Drupal modules or external services for additional functionality

Spark performance problems can arise due to inefficient code, data skew, resource constraints, and improper configuration.

• Inefficient code can lead to slow performance, such as using collect() on large datasets.

• Data skew can cause uneven distribution of data across partitions, impacting processing time.

• Resource constraints like insufficient memory or CPU can result in slow Spark jobs.

• Improper configuration settings, such as too few executors or memory allocation, can hinder p...read more

Bootstrap is a popular front-end framework for building responsive websites and web applications.

• Bootstrap provides pre-designed HTML, CSS, and JavaScript components that can be easily customized and integrated into a project.

• It includes a responsive grid system for creating layouts that adapt to different screen sizes.

• Bootstrap also offers built-in support for popular web development tools like Sass and jQuery.

• Examples of websites built with Bootstrap include Airbnb, Spotify...read more

SQL queries to find duplicates

• Use GROUP BY and HAVING clause to find duplicates

• Use COUNT() function to count the number of occurrences

• Use self-join to compare rows within the same table

• Use subquery to find duplicates in a specific column

The US healthcare ecosystem is a complex network of organizations, providers, payers, and patients working together to deliver healthcare services.

• Includes healthcare providers such as hospitals, clinics, and physicians

• Involves insurance companies, government agencies, and pharmaceutical companies

• Patients play a central role in accessing and receiving healthcare services

• Regulations, policies, and technology also impact the healthcare ecosystem

• Challenges include rising costs, ...read more

Agile process is an iterative approach to software development that emphasizes flexibility and customer satisfaction.

• Agile process involves breaking down the development process into small, manageable chunks called sprints.

• It emphasizes collaboration between team members and with the customer to ensure that the end product meets their needs.

• Agile process values working software over comprehensive documentation.

• It allows for changes to be made throughout the development proces...read more

Renditions are different versions or variations of a digital asset, created to meet specific requirements or optimize performance.

• Renditions are alternate versions of a digital asset, such as images or videos.

• They are created to serve different purposes, such as displaying on different devices or optimizing loading times.

• Renditions can have different resolutions, file formats, compression levels, or color profiles.

• For example, a high-resolution image can have renditions for w...read more

Context API in React is a way to pass data through the component tree without having to pass props down manually at every level.

• Context API provides a way to share values like themes, user data, etc. across the component tree without having to pass props down manually.

• It consists of three main parts: Provider, Consumer, and useContext hook.

• Provider component allows the data to be passed down to the tree, Consumer component consumes the data, and useContext hook allows functio...read more

Various testing techniques like black box testing, white box testing, regression testing, etc. are followed while testing.

• Black box testing focuses on the functionality of the software without looking at the internal code.

• White box testing involves testing the internal code structure, paths, and branches.

• Regression testing ensures that new code changes do not adversely affect existing functionalities.

• Smoke testing is performed to check if the basic functionalities of the soft...read more

Design patterns are used to solve common software design problems and improve code quality.

• Design patterns provide reusable solutions to common software design problems.

• They improve code quality by promoting best practices and reducing code complexity.

• Examples of design patterns include Singleton, Factory, and Observer patterns.

• Reasons for changing design patterns may include improving performance, scalability, or maintainability.

• It is important to carefully consider the trad...read more

Triggers in databases are special stored procedures that are automatically executed when certain events occur.

• Types of triggers include: DML triggers (for INSERT, UPDATE, DELETE operations), DDL triggers (for CREATE, ALTER, DROP operations), and logon triggers.

• Triggers can be classified as row-level triggers (executed once for each row affected by the triggering event) or statement-level triggers (executed once for each triggering event).

• Examples of triggers include: BEFORE I...read more

List is mutable, tuple is immutable in Python.

• List can be modified after creation, tuple cannot be modified.

• List uses square brackets [], tuple uses parentheses ().

• Lists are used for collections of items that may need to be changed, tuples are used for fixed collections of items.

• Example: list_example = [1, 2, 3], tuple_example = (4, 5, 6)

Datalake 1 and Datalake 2 are both storage systems for big data, but they may differ in terms of architecture, scalability, and use cases.

• Datalake 1 may use a Hadoop-based architecture while Datalake 2 may use a cloud-based architecture like AWS S3 or Azure Data Lake Storage.

• Datalake 1 may be more suitable for on-premise data storage and processing, while Datalake 2 may offer better scalability and flexibility for cloud-based environments.

• Datalake 1 may be more cost-effective...read more

Star schema is denormalized with one central fact table surrounded by dimension tables, while snowflake schema is normalized with multiple related dimension tables.

• Star schema is easier to understand and query due to denormalization.

• Snowflake schema saves storage space by normalizing data.

• Star schema is better for data warehousing and OLAP applications.

• Snowflake schema is better for OLTP systems with complex relationships.

repartition increases partitions while coalesce decreases partitions in Spark

• repartition shuffles data and can be used for increasing partitions for parallelism

• coalesce reduces partitions without shuffling data, useful for reducing overhead

• repartition is more expensive than coalesce as it involves data movement

• example: df.repartition(10) vs df.coalesce(5)

The task is to find all pairs in an array that add up to a given sum.

• Iterate through the array and store each element in a hash set.

• For each element, check if the difference between the sum and the element exists in the hash set.

• If it does, add the pair to the result list.

Remove duplicates from array of strings without using set.

• Iterate through the array and compare each element with all other elements to find duplicates.

• Create a new array and add elements only if they are not already present in the new array.

Reverse an integer in Java

• Convert integer to string using Integer.toString()

• Use StringBuilder to reverse the string

• Convert the reversed string back to integer using Integer.parseInt()

Redux is a predictable state container for JavaScript apps, commonly used with React for managing application state.

• Redux helps manage the state of an application in a predictable way

• It provides a single source of truth for the state of the application

• Actions are dispatched to update the state in a predictable manner

• Reducers specify how the state changes in response to actions

• Redux is commonly used with React to manage the state of components

GenAI framework is a platform for developing and deploying AI models for various business analytics purposes.

• GenAI framework is a platform that allows users to develop and deploy AI models for business analytics.

• It provides tools and resources for data preprocessing, model training, and deployment.

• Users can choose from a variety of pre-built models or create their own custom models.

• GenAI framework supports various machine learning algorithms and deep learning architectures.

• Ex...read more

The year over year sales difference is the comparison of sales from one year to the next to determine growth or decline.

• Calculate the total sales for the current year and the previous year

• Subtract the total sales of the previous year from the total sales of the current year

• The result will show the year over year sales difference

Optimization techniques in Spark involve tuning parameters, partitioning data, and using caching.

• Tune parameters like memory allocation, parallelism, and shuffle partitions for better performance

• Partition data to distribute workload evenly across nodes

• Use caching to store intermediate results in memory for faster access

• Examples: repartition(), cache(), persist() functions in Spark

Display in Databricks is used to visualize data in a tabular format or as charts/graphs.

• Display function is used to show data in a tabular format in Databricks notebooks.

• It can also be used to create visualizations like charts and graphs.

• Display can be customized with different options like title, labels, and chart types.

Use Python's 'with' statement to ensure proper resource management and exception handling.

• Use 'with' statement to automatically close files after use

• Helps in managing resources like database connections

• Ensures proper cleanup even in case of exceptions

Parquet file format is a columnar storage format used for efficient data storage and processing.

• Parquet files store data in a columnar format, which allows for efficient querying and processing of specific columns without reading the entire file.

• It supports complex nested data structures like arrays and maps.

• Parquet files are highly compressed, reducing storage space and improving query performance.

• It is commonly used in big data processing frameworks like Apache Spark and Ha...read more

Container creation in terraform involves defining a container resource in a terraform configuration file.

• Define a container resource in the terraform configuration file using the 'docker_container' or 'container' provider.

• Specify the image, name, ports, and other necessary configurations for the container.

• Run 'terraform init' and 'terraform apply' to create the container based on the defined configuration.

Binary tree implementation involves nodes with at most two children, left and right.

• Nodes have a parent-child relationship

• Traversal methods include in-order, pre-order, and post-order

• Balanced vs unbalanced trees affect performance

Drupal best practices involve following coding standards, using modules wisely, optimizing performance, and maintaining security.

• Follow Drupal coding standards to ensure consistency and readability of code

• Use contributed modules from trusted sources and avoid unnecessary custom code

• Optimize performance by caching content, enabling compression, and minimizing database queries

• Maintain security by keeping Drupal core and modules up to date, using secure coding practices, and imp...read more

Drupal Cache Mechanism stores and retrieves data to improve website performance.

• Drupal has multiple cache bins like page cache, block cache, and dynamic page cache.

• Cache tags are used to invalidate specific cache items when content is updated.

• Cache contexts allow different versions of a page to be served based on user roles or languages.

• Cache max-age sets the time for which a cached item is considered valid before it needs to be refreshed.

Order of operation in Tableau determines the sequence in which calculations are performed.

• Tableau follows the standard order of operations: parentheses, exponentiation, multiplication and division (from left to right), addition and subtraction (from left to right)

• Use parentheses to specify the order of operations

• Tableau also allows the use of functions to control the order of operations

Context filter in Tableau allows users to filter data across multiple worksheets or dashboards.

• Context filters are applied to a specific worksheet or dashboard and affect all other worksheets or dashboards connected to the same data source.

• Context filters are useful for creating interactive dashboards where users can easily filter data across different views.

• To create a context filter in Tableau, right-click on a filter and select 'Add to Context'.

Boosting is a machine learning ensemble technique where multiple weak learners are combined to create a strong learner.

• Boosting is an iterative process where each weak learner is trained based on the errors of the previous learners.

• Examples of boosting algorithms include AdaBoost, Gradient Boosting, and XGBoost.

• Boosting is used to improve the accuracy of models and reduce bias and variance.

Vendor prefixes are used in CSS to add experimental features that are not yet standardized.

• Vendor prefixes are added to CSS properties to support experimental features.

• They are used to test new features before they are standardized.

• Examples of vendor prefixes include -webkit-, -moz-, -ms-, and -o-.

• Vendor prefixes should be used sparingly and with caution, as they can cause compatibility issues.

• It is important to include the standard version of the property after the vendor-pr...read more

HashMap is a data structure that stores key-value pairs and uses hashing to efficiently retrieve values.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to find the index in the array where it will be stored.

• If multiple keys hash to the same index, a linked list is used to handle collisions.

• HashMap allows one null key and multiple null values.

• The initial capacity and load factor can be specified when c...read more

Healthcare automation involves using technology to streamline processes and improve efficiency in the medical field.

• Implementing electronic health records (EHR) systems to digitize patient information

• Utilizing telemedicine for remote consultations and monitoring

• Automating appointment scheduling and reminders

• Integrating AI algorithms for medical imaging analysis

• Developing mobile apps for patient engagement and monitoring

C++ is a powerful and versatile programming language commonly used in software development.

• C++ is an object-oriented language

• It is widely used for developing system software, drivers, and games

• C++ is known for its performance and efficiency

Random forest is an ensemble learning method that builds multiple decision trees and merges them to improve accuracy and prevent overfitting.

• Random forest is a type of ensemble learning method.

• It builds multiple decision trees during training.

• Each tree is built using a subset of the training data and a random subset of features.

• The final prediction is made by averaging the predictions of all the individual trees.

• Random forest helps to improve accuracy and prevent overfitting....read more

Count duplicates in an int array

• Create a HashMap to store the count of each element in the array

• Iterate through the array and update the count in the HashMap

• Count the elements with count greater than 1 as duplicates