300+ Nsight Inc Interview Questions and Answers

Explaining differences between left join, right join, union and union all in SQL.

• Left join returns all records from left table and matching records from right table.

• Right join returns all records from right table and matching records from left table.

• Union combines the result sets of two or more SELECT statements and removes duplicates.

• Union all combines the result sets of two or more SELECT statements and includes duplicates.

• Use left join when you want to include all records ...read more

Trees can be solved using recursion by breaking down the problem into smaller subproblems.

• Recursively traverse the tree by calling the function on the left and right child nodes.

• Base case should be when reaching a leaf node or null node.

• Examples: inorder, preorder, postorder tree traversal.

The least common ancestor (LCA) of two nodes in an n-ary tree is the lowest node that has both nodes as descendants.

• The LCA can be found by traversing the tree from the root and checking if both nodes are present in its children.

• If one node is the ancestor of the other, it is considered as the LCA.

• If the nodes are in different subtrees, the LCA will be the root of the tree.

Types of keys in SQL include primary, foreign, and unique. Types of joins include inner, outer, left, and right.

• Primary key: uniquely identifies each record in a table

• Foreign key: links two tables together

• Unique key: ensures that each value in a column is unique

• Inner join: returns only the matching rows from both tables

• Outer join: returns all rows from both tables, with null values for non-matching rows

• Left join: returns all rows from the left table and matching rows from the...read more

The business will be funded through a combination of equity financing, loans, and revenue generation.

• Seeking investment from venture capitalists or angel investors

• Applying for business loans from banks or financial institutions

• Generating revenue through sales of products or services

• Crowdfunding campaigns on platforms like Kickstarter or Indiegogo

To delete a node in a linked list, we need to adjust the pointers of the previous and next nodes.

• Find the node to be deleted by traversing the linked list

• Adjust the pointers of the previous and next nodes to skip the node to be deleted

• Free the memory occupied by the node to be deleted

Chargebacks are a reversal of a credit card transaction by the card issuer.

• Chargebacks occur when a customer disputes a charge on their credit card statement.

• The card issuer investigates the dispute and may reverse the transaction if they find it to be valid.

• Merchants may be charged a fee for each chargeback they receive.

• Common reasons for chargebacks include fraud, product not received, or product not as described.

• Merchants can dispute chargebacks by providing evidence to th...read more

Clean price is the price of a bond excluding accrued interest, while dirty price includes accrued interest.

• Clean price is the price of a bond without the accrued interest, while dirty price includes the accrued interest.

• Clean price is also known as flat price, while dirty price is also known as full price.

• Clean price is used to calculate the yield of a bond, while dirty price is the actual price paid by the buyer.

Derivatives are financial contracts that derive their value from an underlying asset or security.

• Derivatives can be used for hedging or speculation.

• Common types of derivatives include futures, options, and swaps.

• Futures contracts obligate the buyer to purchase an asset at a predetermined price and time.

• Options contracts give the buyer the right, but not the obligation, to buy or sell an asset at a predetermined price and time.

• Swaps involve exchanging cash flows based on diffe...read more

Cannot answer without knowing the query

Implement a queue using two stacks.

• Use one stack for enqueue operation and another for dequeue operation

• When dequeue is called, pop all elements from stack 1 and push them onto stack 2, then pop from stack 2

• When stack 2 is empty, repeat the process in reverse

• Ensure that enqueue operation always happens on the non-empty stack

Design a system using EC2 instance Fleet on Leetcode platform

• Utilize EC2 instance Fleet to manage a group of EC2 instances for scalability and cost-efficiency

• Implement load balancing to distribute incoming traffic across multiple EC2 instances

• Use auto-scaling to automatically adjust the number of EC2 instances based on traffic demand

• Monitor system performance and health using CloudWatch metrics and alarms

DCF can be affected by inaccurate projections, discount rate assumptions, and terminal value estimates.

• DCF relies heavily on projections, which can be difficult to accurately predict.

• Discount rate assumptions can also greatly impact the valuation.

• Terminal value estimates can be particularly challenging to determine.

• DCF does not account for external factors such as market volatility or changes in industry trends.

• DCF assumes a constant growth rate, which may not be realistic in...read more

Investment banking is a type of financial service that helps companies and governments raise capital by underwriting and selling securities.

• Investment banks act as intermediaries between issuers of securities and investors.

• They provide services such as underwriting, mergers and acquisitions, and securities trading.

• Examples of investment banks include Goldman Sachs, JPMorgan Chase, and Morgan Stanley.

Finding the shortest super common string among an array of strings.

• Create a set of all substrings of the first string

• Iterate through the remaining strings and remove substrings not present in them

• Return the shortest remaining substring

Active Directory is a directory service developed by Microsoft for Windows domain networks.

• It stores information about network resources such as computers, users, and groups.

• It provides authentication and authorization services for Windows-based computers.

• It allows administrators to manage and deploy software, policies, and updates to network resources.

• It uses a hierarchical structure of domains and organizational units (OUs) to organize network resources.

• It supports integrat...read more

Handling class imbalance involves techniques such as resampling, adjusting class weights, and using ensemble methods.

• Resampling techniques like oversampling the minority class or undersampling the majority class can help balance the classes.

• Adjusting class weights during model training can give more importance to the minority class.

• Using ensemble methods like bagging or boosting can improve the performance on imbalanced datasets.

• Applying anomaly detection or one-class classif...read more

I have dealt with objections by actively listening, addressing concerns, providing solutions, and building rapport.

• Listen carefully to the objection without interrupting

• Acknowledge the concern and show empathy

• Provide relevant information or solutions to address the objection

• Build rapport and trust by demonstrating expertise and understanding

The Fourier transform of a Gaussian is another Gaussian.

• The Fourier transform of a Gaussian function is given by another Gaussian function.

• The Fourier transform of a Gaussian function is also a Gaussian function.

• The width of the Fourier transform is inversely proportional to the width of the original Gaussian.

• The Fourier transform of a Gaussian function is widely used in signal processing and image processing.

Trisecting a line using scale and compass involves dividing the line into three equal parts.

• Draw a line segment using a ruler

• Place the compass at one end of the line and draw an arc

• Place the compass at the other end of the line and draw another arc

• Draw a line connecting the two points where the arcs intersect

• Divide the line into three equal parts using the ruler

WACC is the weighted average cost of capital, calculated by multiplying the cost of each capital component by its proportional weight and summing the results.

• WACC = (E/V) * Re + (D/V) * Rd * (1 - Tc)

• E/V represents the proportion of equity in the company's capital structure

• Re is the cost of equity

• D/V represents the proportion of debt in the company's capital structure

• Rd is the cost of debt

• Tc is the corporate tax rate

• Example: If a company has 70% equity and 30% debt, with a cos...read more

I have worked with tools such as Apache Spark, Hadoop, and SQL databases.

• Apache Spark

• Hadoop

• SQL databases

Use a hashmap to store the frequency of each character and then iterate through the string to find the first non-repeating character.

• Create a hashmap to store the frequency of each character in the string.

• Iterate through the string and update the frequency in the hashmap.

• Iterate through the string again and return the first character with frequency 1.

Inheritance in Java allows a class to inherit properties and behavior from another class.

• Inheritance allows for code reusability and promotes a hierarchical relationship between classes.

• Subclasses can access the methods and fields of their superclass.

• Example: class Dog extends Animal {} - Dog inherits properties and behavior from Animal class.

Create a Binary Search Tree (BST) from an incoming stream of nodes.

• Start with an empty BST

• For each incoming node, compare it with the root node and insert it accordingly

• Repeat the process until all nodes are inserted

Implement LRU cache

• LRU stands for Least Recently Used

• It is a cache eviction policy that removes the least recently used item

• It can be implemented using a doubly linked list and a hash map

• Newly accessed items are moved to the front of the list

• When the cache is full, the item at the end of the list is removed

To check if a BT is BST or not, we need to traverse the tree and check if the left child is smaller and right child is greater than the parent node.

• Traverse the tree using inorder traversal

• Check if the left child is smaller than the parent node

• Check if the right child is greater than the parent node

• Repeat the above steps for all nodes in the tree

• If all nodes follow the above conditions, then the tree is a BST

XGBoost is an optimized version of Gradient Boosting Machine (GBM) with additional features and improvements.

• XGBoost is a scalable and efficient implementation of gradient boosting algorithm.

• XGBoost uses a more regularized model formalization to control overfitting.

• XGBoost supports parallel processing and can handle large datasets.

• XGBoost provides built-in regularization techniques like L1 and L2 regularization.

• XGBoost has a variety of objective functions and evaluation metri...read more

Implement two stacks in a single array using two different approaches

• Divide the array into two halves and use one half for each stack

• Use two pointers, one for each stack, and move them towards each other as elements are pushed or popped

• Consider edge cases like stack overflow and underflow

Designing an Olympic game that tests physical and mental abilities.

• Include a mix of individual and team events

• Incorporate traditional sports like track and field, swimming, and gymnastics

• Include non-traditional events like obstacle courses and mental challenges

• Have a closing ceremony that celebrates all athletes and their achievements

Producer consumer problem is a synchronization problem in which a producer produces data and a consumer consumes it.

• The producer and consumer share a common buffer.

• The producer produces data and puts it in the buffer.

• The consumer consumes data from the buffer.

• The problem arises when the buffer is full or empty.

• Solutions include using semaphores, mutexes, and monitors.

DCF is a valuation method used to estimate the value of an investment based on its future cash flows.

• Forecast future cash flows

• Determine the discount rate

• Calculate the present value of cash flows

• Sum the present values to get the total value of the investment

Prioritizing projects involves assessing their importance, urgency, resources required, and impact on overall goals.

• Evaluate the importance and impact of each project on overall goals

• Assess the urgency of each project and any deadlines that need to be met

• Consider the resources required for each project, such as budget, manpower, and time

• Use prioritization techniques like the Eisenhower Matrix or MoSCoW method

• Communicate with stakeholders to understand their priorities and exp...read more

To find a number in a sorted rotated array, use binary search algorithm.

• Identify the mid element of the array

• Check if the mid element is the target number

• If not, check if the left half or right half of the array is sorted

• If the left half is sorted and the target number falls within that range, search in the left half

• If the right half is sorted and the target number falls within that range, search in the right half

• Repeat the process until the target number is found or the arra...read more

Deferred tax is a liability or asset that arises due to temporary differences between accounting and tax rules.

• Deferred tax arises due to temporary differences between accounting and tax rules

• It can be a liability or asset depending on the nature of the difference

• Examples include depreciation, inventory valuation, and tax credits

• Deferred tax liability is recognized when taxable income is greater than accounting income

• Deferred tax asset is recognized when accounting income is ...read more

A system like Zomato for restaurant discovery and food ordering.

• Create a database of restaurants with details like menu, location, ratings, etc.

• Develop a user-friendly website and mobile app for easy access.

• Implement a search feature for finding restaurants based on location, cuisine, etc.

• Allow users to rate and review restaurants.

• Integrate a secure payment gateway for online food ordering and delivery.

• Partner with restaurants for promotions and discounts.

• Provide analytics an...read more

Design a distributed rate limiter for managing incoming requests.

• Use a distributed key-value store like Redis to store request counts and timestamps.

• Implement a token bucket algorithm to control the rate of incoming requests.

• Use a distributed messaging system like Kafka for communication between rate limiter instances.

• Consider using consistent hashing to evenly distribute requests among rate limiter instances.

SQL is a traditional relational database management system, while NoSQL is a non-relational database system.

• SQL is structured, uses tables with predefined schema, and is good for complex queries.

• NoSQL is unstructured, uses collections or documents, and is good for large amounts of data with simple queries.

• SQL is ACID compliant, ensuring data integrity, while NoSQL is BASE (Basically Available, Soft state, Eventually consistent) for scalability and flexibility.

• Examples of SQL ...read more

Reverse a linked list recursively by swapping pointers

• Start by checking if the current node is null or the next node is null

• If so, return the current node as it is the new head of the reversed list

• Otherwise, recursively call the function on the next node and swap pointers

Use a subquery to find the second highest value in a SQL table.

• Use a subquery to select the maximum value from the table.

• Then use another subquery to select the maximum value that is less than the maximum value found in the first subquery.

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

• Inner join returns only the rows that have matching values in both tables

• It is used to retrieve data that exists in both tables

• Example: SELECT Orders.OrderID, Customers.CustomerName FROM Orders INNER JOIN Customers ON Orders.CustomerID = Customers.CustomerID;

Quick sort is a popular sorting algorithm that uses divide and conquer strategy.

• Divide the array into two sub-arrays based on a pivot element

• Recursively sort the sub-arrays

• Combine the sorted sub-arrays

Hedge funds use fund accounting to track investments, manage risks, and report performance.

• Hedge funds use fund accounting to accurately track the value of their investments.

• Fund accounting helps hedge funds manage risks by providing detailed information on asset allocation.

• Reporting performance to investors is a key aspect of fund accounting for hedge funds.

• Examples: calculating NAV, reconciling trades, preparing financial statements.

Trapping rainwater problem

• The problem involves calculating the amount of rainwater that can be trapped between bars in an elevation map

• Use two pointers approach to calculate the water trapped at each bar

• Keep track of the maximum height on the left and right of each bar to calculate the trapped water

Search for a target value in a sorted n*n matrix.

• Start from the top-right corner or bottom-left corner of the matrix.

• Compare the target value with the current element and move left or down accordingly.

• Repeat until the target value is found or the boundaries of the matrix are crossed.

The gas and track problem involves determining the amount of gas required to complete a track.

• Calculate the distance of the track

• Determine the fuel efficiency of the vehicle

• Divide the distance by the fuel efficiency to get the required amount of gas

A min stack is a stack data structure that supports the usual push and pop operations, along with an additional operation to retrieve the minimum element in constant time.

• Create a stack to store the elements and another stack to store the minimum values encountered so far.

• When pushing an element, check if it is smaller than the current minimum. If so, push it onto the minimum stack.

• When popping an element, check if it is equal to the current minimum. If so, pop from the minim...read more

OOP focuses on objects and classes, while POP focuses on procedures and functions.

• OOP emphasizes data encapsulation and inheritance

• POP emphasizes sequential execution of procedures

• Example of OOP: Java, C++

• Example of POP: C, Pascal

Binary search on rotated array involves finding a target value in a sorted array that has been rotated at an unknown pivot point.

• Identify the pivot point by finding the minimum element in the array.

• Divide the array into two subarrays based on the pivot point.

• Perform binary search on the appropriate subarray to find the target value.

Interest is the cost of borrowing money or the return on invested funds.

• Interest is the amount charged by a lender to a borrower for the use of assets.

• It can also refer to the income earned on an investment.

• There are different types of interest such as simple interest and compound interest.

• For example, when you take out a loan, you will have to pay back the principal amount plus interest.

• On the other hand, if you deposit money in a savings account, you will earn interest on y...read more

Design the Low Level Design (LLD) for a Parking Lot System

• Divide the system into modules like parking lot, vehicle, ticket, payment, etc.

• Define the classes and their relationships, such as ParkingLot, Vehicle, Ticket, Payment

• Include methods for functionalities like parking a vehicle, issuing a ticket, processing payment

• Consider scalability and performance aspects in the design

• Implement data structures like queues for managing parking spots

Designing a notification system for efficient communication and updates.

• Identify the target audience for the notifications (employees, customers, etc.)

• Determine the types of notifications needed (urgent alerts, general updates, reminders, etc.)

• Choose the appropriate communication channels (email, SMS, app notifications, etc.)

• Implement a user-friendly interface for managing notification preferences

• Include options for customization and personalization of notifications

My current process involves analyzing data, identifying trends, and creating reports to support decision-making.

• Collecting relevant data from various sources

• Using statistical tools and software to analyze data

• Creating visualizations and reports to communicate findings

• Presenting findings to stakeholders for decision-making

Various types of loans offered include personal loans, home loans, auto loans, student loans, and business loans.

• Personal loans

• Home loans

• Auto loans

• Student loans

• Business loans

Design a Netflix OTP system.

• Use a secure algorithm to generate OTPs.

• Implement a time-based OTP system.

• Integrate with a reliable SMS gateway for OTP delivery.

• Implement rate limiting to prevent brute force attacks.

• Provide an option for users to disable OTP for trusted devices.

• Ensure compliance with data privacy regulations.

Recursion is a programming technique where a function calls itself in order to solve a problem.

• Recursion involves breaking down a problem into smaller subproblems and solving them recursively.

• A base case is needed to stop the recursion and prevent infinite loops.

• Examples of recursive functions include factorial calculation and Fibonacci sequence generation.

HashMap is a data structure that stores key-value pairs and uses hashing to quickly retrieve values based on keys.

• 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 determine the index in the array where the pair will be stored.

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

• HashMap allows null keys and values, but only one null key.

• Example: HashMap map = new HashMa...read more

I have experience with high salary expectations.

• I have experience negotiating high salaries based on my skills and experience.

• I have successfully secured high salary offers in previous roles.

• I am confident in my ability to justify and negotiate for a high salary based on market rates and my qualifications.

I have extensive experience in bulk hiring, including sourcing, screening, and onboarding large numbers of candidates efficiently.

• Managed end-to-end recruitment process for bulk hiring projects

• Utilized various sourcing strategies to attract a high volume of candidates

• Implemented streamlined screening and assessment processes to quickly identify qualified candidates

• Coordinated logistics for large-scale recruitment events

• Collaborated with hiring managers to ensure timely onboar...read more

Designing a file system involves organizing and managing data on a storage device.

• Consider the type of data to be stored and access patterns

• Choose a suitable file system structure (e.g. FAT, NTFS, ext4)

• Implement features like file permissions, encryption, and compression

• Plan for scalability and backup strategies