Perfisys Interview Questions and Answers

First round is aptitude test which consists of time and work, number series, blood relation etc..

Q1. You have to be prepared with the Android dev questions like Android architecture, MVVM, Android activity lifecycle, retrofit, firebase.
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Q2. Explain the Activity lifecycle in Android.
Ans. 
The Activity lifecycle in Android refers to the sequence of events that occur during the lifespan of an Activity.
• An Activity goes through several states, including onCreate, onStart, onResume, onPause, onStop, and onDestroy.

• Each state has its own purpose and is triggered by specific events, such as the user opening or closing the app.

• Understanding the Activity lifecycle is crucial for managing resources, saving and res...read more
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Q3. What is the difference between Serializable and Parcelable?
Ans. 
Serializable is a marker interface that allows objects to be converted into a byte stream, while Parcelable is an Android-specific interface for efficient object serialization.
• Serializable is a standard Java interface, while Parcelable is an Android-specific interface.

• Serializable uses reflection to serialize and deserialize objects, which can be slower and less efficient.

• Parcelable requires explicit implementation of ...read more
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Q4. Describe the differences between AsyncTask and RxJava for handling background tasks in Android.
Ans. 
AsyncTask is a built-in class for handling background tasks in Android, while RxJava is a library that provides a more flexible and powerful approach.
• AsyncTask is a class provided by the Android framework, while RxJava is a third-party library.

• AsyncTask is based on the traditional thread and callback model, while RxJava uses the concept of Observables and allows for more complex asynchronous operations.

• RxJava provides ...read more
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Q5. Explain the usage of Fragments in Android and when you might prefer using them over Activities.
Ans. 
Fragments are reusable UI components in Android that can be used within activities. They are preferred over activities in certain scenarios.
• Fragments allow for modular and reusable UI components.

• They can be used to create multi-pane layouts for tablets and larger screens.

• Fragments can be added or removed dynamically at runtime.

• They can retain their state during configuration changes.

• Fragments can communicate with each ...read more
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Based on Mern for me

Q1. HOW YOU WILL SOLVE FOR BETTER OPTIMIZATION FOR A WEBSITE
Ans. 
To optimize a website, I would focus on improving page load speed, optimizing images and code, implementing caching, and minimizing HTTP requests.
• Optimize images by compressing them and using the appropriate file format (e.g., JPEG for photos, PNG for graphics)

• Minimize HTTP requests by combining CSS and JavaScript files, and using CSS sprites for multiple images

• Implement caching to store static resources on the user's ...read more
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