XpressBees Interview Questions and Answers

MVVM stands for Model-View-ViewModel, a design pattern that separates the UI from the business logic.

• MVVM separates the UI (View) from the business logic (ViewModel) by introducing a middle layer (ViewModel) that handles the communication between the two.

• Model represents the data and business logic, View represents the UI components, and ViewModel acts as an intermediary between them.

• MVVM promotes better code organizat...read more

lateinit is used for non-nullable properties that are initialized in the constructor, while lazy is used for properties that are initialized only when accessed for the first time.

• lateinit is used for properties that must be initialized before being used, while lazy is used for properties that can be initialized later.

• lateinit properties must be of non-nullable types, while lazy properties can be nullable.

• lateinit prope...read more

Different Coroutines launchers in Android and their differences.

• MainCoroutineDispatcher - runs on the main thread and is used for UI updates.

• IOCoroutineDispatcher - optimized for IO-bound tasks like network requests or database operations.

• DefaultCoroutineDispatcher - suitable for CPU-bound tasks that don't require the main thread.

• UnconfinedCoroutineDispatcher - runs on the current thread until the first suspension poin...read more

Supervisor Scope is used in structured concurrency for managing child coroutines, while Coroutine Scope is used for launching coroutines.

• Supervisor Scope is used to manage the lifecycle of child coroutines, ensuring that if one child fails, it does not affect the others.

• Coroutine Scope is used for launching coroutines and managing their lifecycle.

• SupervisorScope is a part of the Kotlin coroutines library, while Corouti...read more

Different push notifications can be sent to other users by targeting specific user IDs or using topics in Firebase Cloud Messaging.

• Use Firebase Cloud Messaging to send push notifications to specific user IDs.

• Utilize topics in Firebase Cloud Messaging to send notifications to groups of users with similar interests or characteristics.

• Implement logic in the backend to determine which users should receive which notificatio...read more

Yes, foreground services can be launched if application is in background.

• Foreground services can be launched even if the application is in the background to perform tasks that are noticeable to the user.

• Foreground services have a higher priority than background services and are less likely to be killed by the system.

• Examples of foreground services include music playback, navigation, or ongoing downloads.

Retrofit is a type-safe HTTP client for Android and Java. It simplifies making REST API calls.

• Create a Retrofit instance using Retrofit.Builder class

• Define an interface with method definitions for API endpoints

• Use annotations like @GET, @POST, @PUT, @DELETE to specify the type of HTTP request

• Execute the API call using Call object and Callback interface

• Handle the response in onResponse() and onFailure() methods

Use Room database migration with SQLite ALTER TABLE command to add a new column without losing previous data.

• Create a new migration class in Room database with SQLite ALTER TABLE command to add the new column.

• Ensure that the new column is nullable or has a default value to prevent issues with existing data.

• Update the entity class in the code to include the new column and handle it accordingly in the app.

• Test the migrat...read more

LiveData is an observable data holder class. MutableLiveData is a subclass of LiveData that allows data to be changed.

• LiveData is an observable data holder class that is lifecycle-aware.

• MutableLiveData is a subclass of LiveData that allows data to be changed.

• Methods of MutableLiveData include setValue() and postValue().

• setValue() updates the value on the main thread, while postValue() updates the value asynchronously.

• L...read more

Configuration changes refer to modifications made to settings or parameters in software or hardware systems.

• Configuration changes can include adjustments to network settings, display preferences, security settings, etc.

• Examples of configuration changes include changing the screen resolution on a computer, updating the Wi-Fi password on a router, or modifying notification settings on a smartphone.

MVVM project folder structure organizes code into separate layers for better maintainability and scalability.

• Separate folders for Models, Views, ViewModels, and Services

• Models folder contains data classes representing the data structure

• Views folder contains XML layout files for UI components

• ViewModels folder contains classes that handle business logic and interact with the data layer

• Services folder contains classes for...read more

HTTP interceptors are used to intercept and modify HTTP requests and responses in an application.

• HTTP interceptors are commonly used in web development to add authentication tokens, logging, error handling, or other functionalities to HTTP requests and responses.

• They can be used to modify headers, add authorization tokens, log requests, handle errors, or perform any other pre-processing or post-processing tasks.

• Example...read more

JVM static vs Companion object in Kotlin

• JVM static is used in Java to create static methods and variables within a class

• Companion object in Kotlin serves a similar purpose to JVM static, providing a way to define static members within a class

• Companion objects can implement interfaces, extend classes, and have their own methods and properties

• JVM static members are accessed using the class name, while companion object me...read more

Companion objects in Kotlin can be accessed from Java code using the @JvmStatic annotation.

• Use the @JvmStatic annotation on companion object functions or properties to access them from Java code.

• In Java code, access companion object members using the class name followed by the Companion keyword.

Google recommends targeting the latest SDK version for better performance and security.

• Google recommends targeting the latest stable SDK version for new apps

• Updating targetSdkVersion can improve app performance and security

• It is important to regularly update targetSdkVersion to stay compliant with Google Play Store policies

Use geocoding APIs to convert location data into human-readable addresses.

• Use geocoding APIs like Google Geocoding API or OpenCage Geocoding API to convert latitude and longitude coordinates into human-readable addresses.

• Display the address instead of a map to show the rider's location.

• Allow riders to input their address manually if they prefer not to share their location.

Remove duplicates from sorted array in place and return number of unique elements.

• Use two pointers approach to iterate through the array and remove duplicates in place.

• Keep track of the current unique element and update the array accordingly.

• Return the count of unique elements after removing duplicates.

In my last LIME department, we focused on collaboration, efficiency, and innovation to enhance our operational processes.

• Implemented a streamlined communication system that reduced response times by 30%.

• Conducted regular team meetings to ensure alignment on goals and foster collaboration.

• Utilized project management tools to track progress and allocate resources effectively.

• Encouraged feedback loops, allowing team membe...read more

I prioritize tasks, delegate effectively, and utilize tools to streamline ground-level delivery work for maximum efficiency.

• Prioritization: I use the Eisenhower Matrix to categorize tasks by urgency and importance, ensuring critical tasks are addressed first.

• Delegation: I assess team strengths and delegate tasks accordingly, as seen when I assigned project components based on individual expertise.

• Time Management: I imp...read more

I worked as a Customer Support Representative at XYZ Corp, assisting clients with inquiries and resolving issues efficiently.

• Handled an average of 50 customer inquiries daily, providing timely and accurate information.

• Resolved customer complaints by identifying the root cause and offering effective solutions, improving satisfaction rates.

• Collaborated with cross-functional teams to streamline processes, resulting in a 2...read more

I am looking for a competitive salary that reflects my skills and experience, ideally in the range of $X to $Y.

• Research industry standards: For example, similar roles in my area typically offer between $X and $Y.

• Consider my experience: With over Z years in customer service, I bring valuable skills that justify a higher salary.

• Flexibility: I am open to discussing a salary that aligns with the company's budget and my qua...read more