Principal Engineer Interview Questions
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Principal Engineer interview questions shared by candidates
Given a large document and a short pattern consisting of a few words (eg. W1 W2 W3), find the shortest string that has all the words in any order (for eg. W2 foo bar dog W1 cat W3 -- is a valid pattern)
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This is a classic minimal window problem described in detail here - http://www.leetcode.com/2010/11/finding-minimum-window-in-s-which.html. Less
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import java.util.*; class Untitled { public static void main(String[] args) { String[] strs = {"a","b","d","e","x","b","z","s","x","c","e","c","d","b"}; String[] pattern = {"b","z","x"}; getMin(strs, pattern); } private static void getMin(String[] strs, String[] pattern){ //initialize the set HashSet set = new HashSet(); for(int i = 0; i map = new HashMap(); for(head = 0; head map, String[] strs, int position){ if (!map.containsKey(strs[position])) return true; if (map.get(strs[position]) <= 1) return false; return true; } } Less
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Could you please explain this??
Common algorithm question
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I solved this problem correctly and explained what I did , also during writing each line I was explaining why I am writing it. But still no next round . Very useless .... I suggest do not spend your energy for this dead old company. Less
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Could you please share the leetcode difficulty of the problems asked during the interview? Less
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The key in these questions is to cover the fundamentals, and be ready for the back-and-forth with the interviewer. Might be worth doing a mock interview with one of the Oracle or ex-Oracle Principal Software Engineer experts on Prepfully? They give real-world practice and guidance, which is pretty helpful. prepfully.com/practice-interviews Less
Code for some rest services where a user can see & buy the applicable games.
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If anyone needs the code which I wrote, then comment & I will share the code. As this code will give you basic setup at least, so that you can concentrate to develop your innovative ideas. Less
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Just don't believe on the positive Glassdoor reviews for a company which has recently started. Less
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Don't believe on the positive reviews directly, these companies fake such positive feedback to trap the talent & may be at low price. Less
Design round: Design an api rate limiter Coding round: simple manipulation of arrays and maps Craft round: Design an ML Labelling system
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There will be many documents in a document database. The labelling system must use machine learning to label into different categories. Eg help desk, system document, technical. There will a small train dataset available but not entirely reliable. Less
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The correct answer would be to use a combination of weak learning methods and gradually incorporate feedback and make it stronger Less
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APi rate limiter was really simple, just look at uber/ratelimit on git and thats it. Rest was farily easy Less
Coding in each round, Firewall, networking questions
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LC Medium or Hard.
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LC Medium or Hard?
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Through questions like this, interviewers are mostly trying to test your skillset (and its relevance to the role) as robustly as possible, so be prepared for multiple offshoots and followups. It could be a useful exercise to do mocks with friends or colleagues in Palo Alto Networks to get a real sense of what the interview is actually like. Alternatively Prepfully has a ton of Palo Alto Networks Principal Software Engineer experts who provide mock interviews for a pretty reasonable amount. prepfully.com/practice-interviews Less
analytical- there are 50 floors in a building. You are given two balls which can break at a certain f trheight . Give a solution where you can determine the critical height at which a ball breaks. the solution should be optimised to give the least no. of tries for the worst case scenario(i.e where the ball breaks on the 50th floor only)
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first ball --- throw it every floor from the iteration the second balls breaks second ball --- throw it every 3 or 4 or 5 floor ... When the second ball breaks, you know there are only 3 or 4 or 5 floors to check ... O (log n) complexity ... best case O(1) Less
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i'll go with binary search procedure..since it stands a better chance
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think over !!
Java, Database and scripting questions
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The key in these questions is to cover the fundamentals, and be ready for the back-and-forth with the interviewer. Might be worth doing a mock interview with one of the Dell or ex-Dell Principal Software Engineer experts on Prepfully? They give real-world practice and guidance, which is pretty helpful. prepfully.com/practice-interviews Less
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How long did it take for you receive the offer after the final interview?
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Did your technical interviews include coding on a white board?
TTD with pair programming.
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what was the data structure implementation, if you don't mind?
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How soon were these interviews scheduled ?
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Through questions like this, interviewers are mostly trying to test your skillset (and its relevance to the role) as robustly as possible, so be prepared for multiple offshoots and followups. It could be a useful exercise to do mocks with friends or colleagues in Dell to get a real sense of what the interview is actually like. Alternatively Prepfully has a ton of Dell Principal Software Engineer experts who provide mock interviews for a pretty reasonable amount. prepfully.com/practice-interviews Less
Print unique strings in a array.
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Used HashSet to keep track of string that were already seen.
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1) Build a Trie and just then just walk and print it then... 2) Like above, use hash, however, this is challenging if you can have unbounded string... as definition of string.... char-sequence-until-null so potential input can one huge sequence.... if it is known that string can be resonably 256 char long at max and all english letter then you can make hash function. Less
The VCR Plus feature was described. In the TV programming guide each program/show/movie had its own code. When user wanted to program the VCR to record a particular show she just had to enter the program code from the guide - no need to enter the start and end time. I was asked to design this feature. How can it be achieved?
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Assuming that TV shows start and end at the 1 min interval (ie won't need to set the start to 1:35:28), there are 1440 mins in 24 hours. One solution would be to have an 8 digit VCR Plus code: xxxxyyyy The first 4 digits will be the start time, second 4 digits will be the end time. This will take 8 bytes of space. Less
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Actually the VCR+ has 30 minute resolution. It packs the info into binary bits, then converts from binary to decimal, saving digits. The Java code is here: http://www.gginc.biz/java/vcr1.html Less