30+ Pagarbook Interview Questions and Answers

A doubly-linked list is a data structure where each node contains a reference to both the previous and next nodes.

• Allows traversal in both directions

• Used in implementing LRU cache

• Used in browser history

• Used in undo-redo functionality

In-memory DB stores data in RAM for faster access while MySQL stores data on disk.

• In-memory DB is faster than MySQL as it eliminates disk I/O operations.

• In-memory DB is suitable for real-time applications that require low latency.

• MySQL is suitable for applications that require data persistence and durability.

• In-memory DB may not be suitable for large datasets as it requires a lot of RAM.

• MySQL supports complex queries and transactions while In-memory DB may not.

• Examples of In-...read more

Print internal nodes of a binary tree (excluding left and right view nodes)

• Traverse the tree in post-order and check if the node has both left and right children

• If yes, then it is an internal node and print it

• If no, then continue traversing the tree

• Example: For the tree 1-2-4-5-3, the internal nodes are 2 and 4

Doubly linked list allows traversal in both directions, while singly linked list only allows traversal in one direction.

• Doubly linked list allows for efficient deletion of nodes compared to singly linked list.

• Doubly linked list can be traversed in both forward and backward directions.

• Doubly linked list can be used to implement a stack or queue.

• Singly linked list requires less memory than doubly linked list.

• Doubly linked list is more complex to implement than singly linked lis...read more

The question is unclear and requires clarification.

• The question is not specific about what 'above question' it is referring to.

• The term 'internal working' is also vague and needs to be defined.

• Without more information, it is impossible to provide a meaningful answer.

Graph data structure is used in various applications such as social networks, routing algorithms, and recommendation systems.

• Social networks use graphs to represent users and their connections.

• Routing algorithms use graphs to find the shortest path between two points.

• Recommendation systems use graphs to analyze user behavior and suggest relevant items.

• Graphs are also used in computer networks, image processing, and machine learning.

• Examples include Dijkstra's algorithm, PageR...read more

RDBMS is a structured database that uses SQL while NoSQL is a non-relational database that doesn't use SQL.

• RDBMS stores data in tables with predefined schema while NoSQL stores data in documents, key-value pairs, or graphs.

• RDBMS is good for complex queries and transactions while NoSQL is good for scalability and handling unstructured data.

• Examples of RDBMS include MySQL, Oracle, and SQL Server while examples of NoSQL include MongoDB, Cassandra, and Redis.

Product Manager interview questions on product strategy

• 1) Daily revenue generated by Facebook Ads is around $80 million

• 2) Improve parking valet system by implementing a mobile app for booking and payment, using sensors to track available parking spots, and training staff on customer service

• 3) Online car marketplace business should explore the vertical of car maintenance and repair services

Indexing is the process of organizing data in a database or search engine to improve search efficiency.

• Indexing creates a data structure that allows for faster retrieval of information.

• It involves creating an index that maps the location of data in a database or search engine.

• Indexing can be done on various types of data, such as text, numbers, and dates.

• Examples of indexing methods include B-tree, hash, and bitmap indexing.

Engage users with interactive content, collaborate with influencers, utilize hashtags and trends.

• Create engaging and interactive content to attract users organically.

• Collaborate with influencers or industry experts to reach a wider audience.

• Utilize popular hashtags and trends to increase visibility and attract new users.

• Host Twitter chats or Q&A sessions to engage with potential users and showcase the value of your product or service.

map, reduce, and filter are higher-order functions in JavaScript used to manipulate arrays.

• map: creates a new array by applying a function to each element of the original array

• reduce: applies a function to an accumulator and each element in the array, reducing it to a single value

• filter: creates a new array with all elements that pass a test implemented by a provided function

To add a new monetisation channel on Instagram, consider implementing features like in-app purchases, sponsored posts, affiliate marketing, and subscription services.

• Implement in-app purchases for users to buy virtual goods or premium features within the app.

• Introduce sponsored posts where businesses pay to have their content promoted to a larger audience.

• Explore affiliate marketing by partnering with brands to earn commission on sales generated through your platform.

• Offer su...read more

Drop in prime membership renewal among Indian users - RCA identification

• Analyze user feedback and complaints

• Evaluate pricing and benefits of prime membership

• Assess competition and market trends

• Review user engagement and retention strategies

• Consider cultural and regional factors

• Investigate technical issues and glitches

• Conduct surveys and focus groups

• Identify areas for improvement and implement solutions

let and var are both used to declare variables in JavaScript, but they have some key differences.

• let is block-scoped, while var is function-scoped

• let variables are not hoisted, while var variables are hoisted

• let variables can be reassigned, while var variables can be redeclared

• let variables have temporal dead zone, while var variables do not

The box model is a concept in CSS that describes how elements are rendered on a web page.

• The box model consists of four components: content, padding, border, and margin.

• The content refers to the actual content of the element, such as text or images.

• The padding is the space between the content and the border.

• The border is a line that surrounds the content and padding.

• The margin is the space outside the border, separating the element from other elements.

• The box model allows dev...read more

Merging two sorted arrays and finding the first occurrence of one in an infinite array of 0 and 1.

• Use the merge sort algorithm to merge two sorted arrays.

• For finding the first occurrence of one in an infinite array, use binary search with an expanding range.

• Handle edge cases like empty arrays or infinite array with no occurrence of one.

It is difficult to estimate the exact number of cars in Delhi due to various factors.

• Delhi has a population of over 18 million people, and a large number of them own cars.

• The number of cars in Delhi is constantly increasing due to rising income levels and urbanization.

• Factors such as traffic congestion, pollution, and government policies also affect the number of cars in Delhi.

• One can estimate the number of cars in Delhi by analyzing data from vehicle registration authorities...read more

There are approximately 1.5 million cabs in India.

• Consider the population of India (around 1.3 billion) and the ratio of cabs to population.

• Take into account the number of registered taxis in major cities like Mumbai, Delhi, Bangalore, etc.

• Factor in the number of ride-sharing services like Ola and Uber operating in the country.

Connected components of a graph are groups of vertices that are connected to each other through edges.

• Connected components are disjoint subgraphs within a graph.

• Each vertex in a connected component is reachable from every other vertex in the same component.

• Examples: In a graph with vertices {A, B, C, D} and edges {(A, B), (B, C)}, the connected components are {A, B, C} and {D}.

SOLID principles are a set of five design principles in object-oriented programming to make software designs more understandable, flexible, and maintainable.

• S - Single Responsibility Principle: A class should have only one reason to change.

• O - Open/Closed Principle: Software entities should be open for extension but closed for modification.

• L - Liskov Substitution Principle: Objects of a superclass should be replaceable with objects of its subclasses without affecting the func...read more

The exact number of two wheelers in Delhi is not available.

• The exact number of two wheelers in Delhi is not publicly disclosed.

• The number of two wheelers in Delhi is constantly changing due to new registrations and retirements.

• The Delhi government periodically conducts surveys to estimate the number of two wheelers in the city.

• The number of two wheelers in Delhi is expected to be in the millions.

• Two wheelers are a popular mode of transportation in Delhi due to their affordabi...read more

Hoisting in JavaScript is the behavior where variable and function declarations are moved to the top of their containing scope during the compilation phase.

• Variable declarations are hoisted to the top of their scope, but not their assignments.

• Function declarations are fully hoisted, meaning they can be called before they are declared.

• Hoisting can lead to unexpected behavior if not understood properly.

Closures in JavaScript allow functions to access variables from their outer scope even after the outer function has finished executing.

• Closures are created when a function is defined within another function and the inner function has access to the outer function's variables.

• Closures can be used to create private variables and functions in JavaScript.

• Closures can also be used to maintain state in asynchronous operations.

Improvements in Instagram include better privacy settings, enhanced content discovery, and improved user interface.

• Enhance privacy settings to give users more control over their personal information

• Improve content discovery algorithms to show users more relevant and engaging content

• Enhance user interface to make it more intuitive and user-friendly

Clauses of agreement refer to specific terms and conditions that are agreed upon by parties involved in a legal contract.

• Clauses of agreement outline the rights, obligations, and responsibilities of each party.

• They provide clarity and prevent misunderstandings or disputes.

• Examples of clauses include payment terms, termination conditions, confidentiality agreements, and dispute resolution mechanisms.