Data Engineer Interview Questions

Ankita G. - "Merge Sort"See full answer

Adarsha S. - " import java.util.*; public class Solution { public static List generateParentheses(int n) { List strings = new ArrayList(); if(n == 0){ return strings; } StringBuilder stringBuilder = new StringBuilder(); stringBuilder.append("("); int openCount = 1; int closeCount = 0; int positions = (n*2)-1; generateBrackets(positions, stringBuilder, strings, openCount, closeCount); r"See full answer

G B. - " select user_id, b.marketing_channel from user_sessions a Left join attribution b on b.sessionid = a.sessionid group by 1,2 HAVING sum(purchasevalue)>100 and min(adclick_timestamp) `"See full answer

Elle - "As a project or program manager to influence effectively without direct authority, focus on building credibility and trust by consistently delivering results, demonstrating empathy for stakeholder needs, and aligning everyone on shared goals. When managing up, tailor communication to leadership’s priorities and concerns—bring actionable insights, clear data, and potential solutions to the table. When managing down, empower teams by promoting ownership, offering timely recognition, and maintainin"See full answer

Akash A. - "not able to understand the accent of the candidate"See full answer

Meenakshi D. - "BETWEEN and HAVING clauses in SQL serve different purposes: 1. BETWEEN Clause Used to filter rows based on a range of values. Works with numeric, date, or text values. Can be used with WHERE or HAVING clauses. The range includes both lower and upper bounds. Example: Filtering employees with salaries between 30,000 and 50,000 `SELECT * FROM Employees WHERE salary BETWEEN 30000 AND 50000;` 2. HAVING Clause Used to filter **groups"See full answer

Rafia M. - "SQL is structured query language."See full answer

Guilherme F. - "A much better solution than the one in the article, below: It looks like the ones writing articles here in Javascript do not understand the time/space complexity of javascript methods. shift, splice, sort, etc... In the solution article you have a shift and a sort being done inside a while, that is, the multiplication of Ns. My solution, below, iterates through the list once and then sorts it, separately. It´s O(N+Log(N)) class ListNode { constructor(val = 0, next = null) { th"See full answer

Mahaboob P. - "int[] sqSorted(int[] nums) { int i = 0, j = nums.length-1; int k = nums.length-1; int[] sqs = new int[nums.length]; while(i n1) { sqs[k--] = n2; j--; } else { sqs[k--] = n1; i++; } } for(int n: sqs) System.out.println(n); return sqs; }"See full answer

Ali H. - "SQL databases are relational, NoSQL databases are non-relational. SQL databases use structured query language and have a predefined schema. NoSQL databases have dynamic schemas for unstructured data. SQL databases are vertically scalable, while NoSQL databases are horizontally scalable."See full answer

Joshua R. - "Hadoop is better than PySpark when you are dealing with extremely large scale, batch oriented, non-iterative workloads where in-memory computing isn't feasible/ necessary, like log storage or ETL workflows that don't require high response times. It's also better in situations where the Hadoop ecosystem is already deeply embedded and where there is a need for resource conscious, fault tolerant computation without the overhead of Spark's memory constraints. In these such scenarios, Hadoop's disk-b"See full answer