10+ Senior Software Engineer L3 Interview Questions and Answers

Design an automated parking lot system with an automated lift for efficient vehicle parking.

• Classes: Vehicle, ParkingLot, ParkingSpace, Lift, Ticket.

• Vehicle class can have attributes like licensePlate, size, and type (e.g., car, motorcycle).

• ParkingLot class manages multiple ParkingSpaces and the Lift.

• Lift class handles the movement of vehicles between different floors.

• Ticket class generates a unique identifier for each parked vehicle.

An app similar to Shazam for identifying music

• Use audio fingerprinting to identify songs

• Integrate with music databases to retrieve song information

• Provide user-friendly interface for displaying song details

Flatten a multi-level linked list where nodes have next pointers at all levels.

• Each node has a value, a next pointer, and a child pointer to another linked list.

• The goal is to flatten the list into a single-level linked list.

• Example: Given 1 -> 2 -> 3, where 2 has a child 4 -> 5, the result should be 1 -> 2 -> 4 -> 5 -> 3.

• Use a stack to traverse and flatten the list iteratively or recursively.

Design an on prem Case System for investigators

• Create a user-friendly interface for investigators to input case details

• Include features for assigning cases, tracking progress, and generating reports

• Implement security measures to protect sensitive case information

• Integrate communication tools for collaboration among investigators and stakeholders

Design an automated parking lot system with APIs, database, and classes for efficient vehicle management.

• Define classes: Vehicle, ParkingSpot, ParkingLot, and Ticket.

• Create APIs: /park, /unpark, /status to manage parking operations.

• Database tables: Vehicles, ParkingSpots, Tickets to store relevant data.

• Implement functions: parkVehicle(), unparkVehicle(), getAvailableSpots() for core functionality.

• Consider edge cases: handling full parking lots, invalid vehicle types, and time...read more

Given a list of intervals, find the non-overlapping intervals.

• Sort the intervals based on their start time.

• Iterate through the intervals and keep track of the latest end time.

• If the start time of the current interval is greater than the latest end time, add it to the non-overlapping intervals.

• If the start time of the current interval is less than or equal to the latest end time, skip it as it overlaps with the previous interval.

Reorder a linked list by alternating between the first and last elements

• Create two pointers, one at the beginning and one at the end of the linked list

• Iterate through the linked list, moving the first pointer to the next node and the second pointer to the previous node

• Adjust the pointers to reorder the linked list by alternating between the first and last elements

Tickets and tasks can be handled by prioritizing, assigning, tracking progress, and communicating effectively.

• Prioritize tickets based on urgency and impact on users.

• Assign tasks to team members based on their expertise and workload.

• Track progress using project management tools like Jira or Trello.

• Communicate effectively with team members and stakeholders to provide updates and gather feedback.

• Regularly review and update ticket statuses to ensure timely resolution.

Event loop in JavaScript is responsible for managing asynchronous operations by executing callback functions in a non-blocking way.

• Event loop is a mechanism that allows JavaScript to perform non-blocking I/O operations.

• It continuously checks the call stack and the callback queue, moving functions from the queue to the stack when the stack is empty.

• Event loop ensures that JavaScript remains responsive and can handle multiple operations simultaneously.

Closure in JavaScript is the combination of a function and the lexical environment within which that function was declared.

• Closure allows a function to access variables from its outer scope even after the outer function has finished executing.

• It is created whenever a function is defined within another function.

• Example: function outerFunction() { let outerVar = 'I am outer'; function innerFunction() { console.log(outerVar); } return innerFunction; } let newFunction = outerFunc...read more

Check if a binary tree is a Binary Search Tree (BST) by validating the inorder traversal.

• Perform an inorder traversal of the binary tree and store the elements in a list.

• Check if the list is sorted in ascending order. If yes, then the binary tree is a BST.

• Ensure that there are no duplicate elements in the binary tree.

Micro frontend architecture is an approach to front-end development where a single web application is composed of multiple smaller, independent applications.

• Each micro frontend is responsible for a specific feature or functionality

• Micro frontends can be developed, tested, and deployed independently

• They can be built using different technologies and frameworks

• Communication between micro frontends can be achieved through APIs or events

• Helps in scaling development teams and maint...read more

Thunks are functions that delay the evaluation of an expression, while sagas are middleware for handling side effects in Redux.

• Thunks are used in Redux to delay the evaluation of an action creator function.

• Sagas are used in Redux to handle side effects like asynchronous API calls.

• Thunks are simpler to implement compared to sagas.

• Thunks are synchronous, while sagas are asynchronous.

• Example: Thunk - const fetchData = () => dispatch => { // API call here }; Saga - function* fetc...read more

Redux is a predictable state container for JavaScript apps.

• Actions are dispatched to the store

• Reducers specify how the state changes in response to actions

• Store holds the state of the application

• Components subscribe to the store to get updates

Design a URL shortener system

• Use a unique identifier for each long URL to generate short URL

• Implement a mapping system to redirect short URL to original long URL

• Consider scalability and performance for high traffic volume

• Implement analytics to track usage and performance of short URLs

AWS EC2 instance is a virtual server in Amazon's Elastic Compute Cloud (EC2) service.

• Virtual server in Amazon's EC2 service

• Can be easily scaled up or down based on demand

• Can run various operating systems and applications

• Can be launched in different regions and availability zones

• Example: t2.micro, m5.large, c5.xlarge