Uber Senior Data Engineer Interview Questions and Answers

Q1. SQL question to return the shortest duration of flight to travel from NY to HND
Ans. 
Use SQL query to find shortest flight duration from NY to HND
• Use SQL query with MIN function to find shortest duration

• Filter flights from NY to HND using WHERE clause

• Calculate duration by subtracting arrival time from departure time
Answered by AI
Add your answer
Q2. Pyspark question to read data from a CSV file
Add your answer
Q3. There was no question 3
Add your answer

Q1. Mostly discussions on Projects at my current company, Design choices and spark related concepts used for optimisations.
Add your answer
Q2. SQL question to test syntax knowledge
Add your answer
Q3. HRM typical questions like: Why join Grab?
Add your answer

Test contains 26 questions for me 13 are java based 13 are c++ based

Q1. Indexing in dbms
Ans. 
Indexing in DBMS is a technique to improve the performance of queries by creating a data structure that allows for faster retrieval of data.
• Indexes are created on columns in a database table to speed up the retrieval of rows that match a certain condition.

• Types of indexes include clustered, non-clustered, unique, and composite indexes.

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

• Indexing can...read more
Answered by AI
Add your answer
Q2. Find whether two strings are or not anagrams
Ans. 
Check if two strings are anagrams by comparing the sorted characters in each string.
• Sort the characters in both strings and compare if they are equal.

• Ignore spaces and punctuation when comparing the strings.

• Example: 'listen' and 'silent' are anagrams.

• Example: 'hello' and 'world' are not anagrams.
Answered by AI
View 1 more answer

Q1. Inorder traversal without recursion
Ans. 
Use a stack to simulate the recursive inorder traversal process
• Create an empty stack to store nodes

• Start with the root node and push it onto the stack

• While the stack is not empty, keep traversing left and pushing nodes onto the stack

• Once you reach a leaf node, pop it from the stack, print its value, and move to its right child

• Repeat the process until all nodes have been visited
Answered by AI
Add your answer
Q2. How to make a class final
Ans. 
To make a class final, use the 'final' keyword in the class declaration.
• Use the 'final' keyword before the 'class' keyword in the class declaration

• A final class cannot be subclassed or extended

• Final classes are often used for utility classes or classes that should not be modified
Answered by AI
Add your answer

It was an online assessment. Some coding questions. Some cs fundamental mcqs. SQL query, Rest Api question.

An assignment to create a game using nodejs/ go lang/ java.

Q1. Discussion related to Assignment. Told some changes and told to add some more functionalities.
Add your answer
Q2. Some APIS were given. It was case study. You had to show the dishes to a customer according to his preferences.
Add your answer

Q1. Data structure and algorithm
Add your answer
Q2. Some tricky logical question
Add your answer
Q3. Stack and queue
Add your answer
Q4. Some basic question about system Design
Add your answer

Hackerrank Coding Test, Leetcode medium questions

HLD test, was asked to design an online coding platform like leetcode

Q1. Most interesting project you have worked on
Add your answer
Q2. How do you handle conflict at workplace
Add your answer

Q1. Find the leaves of the tree.
Ans. 
Leaves of a tree are the nodes with no children in a tree data structure.
• Traverse the tree and identify nodes with no children.

• Use depth-first search or breadth-first search algorithms to find leaves.

• Examples: In a binary tree, leaves are nodes with no left or right child.

• In a general tree, leaves are nodes with no children in their child list.
Answered by AI
Add your answer
Q2. Find the LCA of tree.
Ans. 
The Lowest Common Ancestor (LCA) of a tree is the shared ancestor of two nodes farthest from the root.
• Start from the root and traverse the tree to find the paths from the root to the two nodes.

• Compare the paths to find the last common node between them, which is the LCA.

• If one of the nodes is an ancestor of the other, then the ancestor node is the LCA.
Answered by AI
Add your answer

Q1. What projects you worked upon?
Ans. 
I have worked on projects involving web development, mobile app development, and data analysis.
• Developed a web application using React and Node.js for a client in the e-commerce industry

• Created a mobile app using Flutter for a startup in the healthcare sector

• Performed data analysis on customer behavior using Python and SQL for a marketing company
Answered by AI
Add your answer
Q2. What internships you did?
Ans. 
I completed internships at ABC Company and XYZ Company during my undergraduate studies.
• Interned at ABC Company working on web development projects

• Interned at XYZ Company assisting with software testing and quality assurance

• Gained hands-on experience in coding, debugging, and problem-solving
Answered by AI
Add your answer

Aptitude Test + some JAVA + SQL Questions

DSA+SPRING+SQL+JAVA
IN THIS ROUND INTERVIEWER ASKED ME 1DSA QUESTION WHICH IS BASED ON DEQUE SOME SQL QUERIES WHICH IS ON JOINS AND BASIC SPRING QUESTIONS

SAME AS THE 2ND ROUND BUT THE LEVEL INCREASED AS COMPARISON TO ROUND-2

Q1. IN THIS ROUND MANAGER ASKED ME SOME QUESTIONS ABOUT MY BACKGROUND AND COLLEGE PROJECT AND ASKED ABOUT MY PREVIOUS EXP
Add your answer

Implement your own state management in React and integrate it into a React application.