Zepto Senior Data Scientist Interview Questions and Answers for Experienced

Q1. Template and Reactive Forms in Angular
Ans. 
Template and Reactive Forms in Angular are two ways to handle forms in Angular applications.
• Template Forms are based on the traditional HTML forms and are easy to use for simple forms.

• Reactive Forms are more flexible and powerful, allowing for complex form validation and dynamic form controls.

• Template Forms use two-way data binding, while Reactive Forms use a more reactive approach with observables.

• Reactive Forms are r...read more
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Q1. What is event loop, how it works.
Ans. 
Event loop is a mechanism in programming that allows for asynchronous execution of code by continuously checking for and handling events.
• Event loop is commonly used in JavaScript to handle asynchronous operations like setTimeout, setInterval, and AJAX requests.

• It works by continuously checking the event queue for any pending events, executing them one by one, and then moving on to the next event.

• Event loop helps in pre...read more
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Q2. Micro task queue and macro task queue.
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Q3. Is node.js single threaded or multi-threaded, also discuss threadpool and it's usages.
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Q4. Tell the order of output, among process, promise, setTimeout, fs, setInterval.
Ans. 
The order of output is fs, process, setTimeout, setInterval, promise.
• fs module is synchronous and will output first

• process is next in line

• setTimeout will be executed after process

• setInterval will be executed after setTimeout

• promise will be executed last
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Q1. JavaScript usages compiler or interpreter.
Ans. 
JavaScript is an interpreted language.
• JavaScript is an interpreted language, meaning it is executed line by line at runtime.

• There is no separate compilation step in JavaScript like in languages that use compilers.

• Examples of interpreted languages include Python, Ruby, and PHP.
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Q2. Tell the output among various for loops using var, let and bind.
Ans. 
Output comparison of for loops using var, let, and bind in JavaScript.
• Using var: variable is function-scoped, may lead to unexpected behavior in loops.

• Using let: variable is block-scoped, recommended for loop iterations.

• Using bind: creates a new function with a specified 'this' value and initial arguments.
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Q3. A medium level dsa question on array, solved it using pre-sum.
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Q4. Situation based question, on how to pick a suitable database.
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Q1. What do you do on daily basis, and how to decide a tech-stack on high level.
Ans. 
I work on coding, debugging, testing, and collaborating with team members. Tech stack decisions are based on project requirements, scalability, performance, and team expertise.
• Daily tasks include coding, debugging, testing, and collaborating with team members

• Tech stack decisions are based on project requirements, scalability, performance, and team expertise

• Consider factors like language compatibility, libraries/framewo...read more
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Q2. Design an online scalable, real-time document sharing application like google docs.
Ans. 
Design a scalable, real-time document sharing app like Google Docs.
• Use websockets for real-time collaboration

• Implement version control to track changes

• Utilize a distributed database for scalability

• Include user authentication and access control

• Support offline editing with automatic sync
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Q3. How to handle images also in the future.
Ans. 
Utilize cloud storage for scalability, implement image compression techniques, and regularly update image processing libraries.
• Utilize cloud storage for scalability

• Implement image compression techniques

• Regularly update image processing libraries
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Q4. Any other way to solve the problem, of high I/O on same document to overcome throughput and conflicts.
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I was asked question on sliding window on finding the largest subarray with all distinct numbers. The interviewer was very helpful.

Q1. Create a controller , service and repository methods and classes to save userDeatils in table using Spring Data JPA .
Ans. 
Create a controller, service, and repository to save user details using Spring Data JPA.
• Create a UserController class with appropriate mappings for saving user details.

• Create a UserService class with a method to save user details.

• Create a UserRepository interface that extends JpaRepository to handle database operations.

• Implement the saveUserDetails method in the UserService class to call the save method of the UserRepo...read more
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Questions were crayon box ,the bot and the game and happy neighbourhood for 90 mins

Q1. Array basics was asked
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Q2. Segment tree,prefix sum
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Q1. Low level design was asked
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Q1. The hr scheduled a call with the analytics manager ,who asked about my experience and general details ,some background about projects and previous work ,why this job etc .30-40 minutes conversation.
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Q2. Just a casual brief conversation
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Q1. Second round was with a senior analyst ,who asked 5-6 sql related questions , problems to solve etc ,tables to create ,joins ,window functions etc basic sql
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Q2. Very friendly interviewer , you are allowed to google the syntax
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Q1. Another round with the analytics head , case study ,problem solving ,logical reasoning etc.
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Preparing media plan for app campaign at a certain budget and expected installs first orders etc

Q1. Guessestimate and general mathematical aptitude
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Q2. No of petrol pumps in city
Ans. 
The number of petrol pumps in the city is not available.
• I do not have access to the data on the number of petrol pumps in the city.

• It would be best to consult the city's government or relevant authorities for this information.

• Alternatively, one could conduct a survey or research to estimate the number of petrol pumps in the city.
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Q3. How would you optimize the campaigns in terms of bids budgets
Ans. 
Optimizing bids and budgets involves analyzing data, setting goals, and adjusting strategies accordingly.
• Analyze campaign data to identify top-performing keywords and adjust bids accordingly

• Set clear goals for each campaign and allocate budgets accordingly

• Regularly monitor and adjust bids and budgets based on performance data

• Consider using automated bidding strategies to save time and improve efficiency

• Use A/B testing ...read more
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Q1. Why do you want to join meesho
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Q2. Basics of Digital marketing CPM CTR CPC difference
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