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Harder programming questions do a worse job of predicting outcomes

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Re: Harder programming questions do a worse job of predicting outcomes

#421

Post by abhishekjha »

ball_of_lint wrote: post #349
abhishekjha wrote: post #333

Earlier quoted context omitted.

Hi. Where are you learning DP problems from? I am very bad at those and need a few good references so that it sticks in my memory.

I'd suggest kattis and CodeForces. I use kattis mostly, but know a number of people who like codeforces better. Here's a few for you to try. Some of these are pretty hard, but you should be able to find solution sketches online if you google the contests they are from. https://open.kattis.com/problems/increasingsubsequence https://open.kattis.com/problems/maximumsubarrays https://open.kattis.com/problems/tray https:/…

Thank you. I will definitely be coming back. I guess I have difficulty formulating a DP problem properly.

Re: Harder programming questions do a worse job of predicting outcomes

#422

Post by blaze_run »

pcwalton wrote: post #392
kyralis wrote: post #260

Earlier quoted context omitted.

If you're trying to find a situation where that exact solution is going to be useful, you're not thinking about the problem from the right perspective. Handled correctly, a problem like this answers several questions: 1) Can you correctly break down a problem like this into its components parts? 2) Can you recognize the overall class of problems that this falls into? 3) Can you transform this specific problem into th…

If it's true that this type of problem is relevant (I doubt it), then why not ask about a specific problem you've actually had to solve? I don't do many interviews anymore, but I used to, and I had no short supply of problems that I actually had to solve in the course of my work that I could ask about. I don't think whiteboard interviewing is great in general, but if you're going to do it you can at least try to keep…

Using an actual problem you solved can also work against the candidate because most problems we encounter in our daily jobs require a lot more time than the standard 45 minutes reserved for an interview (actually only 35 minutes out of 45 because there's 5 minutes of intro/icebreaker and 5 minutes reserved at the end to answer any of the candidate's questions).

So it isn't fair to ask the candidate to solve a real bug or implement a real feature in only 35 minutes unless they've seen something similar before.

This is why big companies like Google are limited to whiteboarding interviews because they need to have an interview process efficient enough to properly vet and filter >1 million applicants Google receives each year.

Personally, I think a better interview process is a pair-programming or work audition for a day. But that is not even close to matching the scale of Google.

Let's say out of a million applications, maybe only 25% are qualified. That is still almost 1000 candidates to interview per day (number of U.S. business days in 2019 is 261; 250,000 candidates / 261 business days = ~957 candidates per business day). Pair-programming or full day work audition will not be able to accommodate 957 candidates every day.

Re: Harder programming questions do a worse job of predicting outcomes

#423

Post by 1000units »

thedufer wrote: post #418
1000units wrote: post #72

Earlier quoted context omitted.

The elephant in the room is that it's a surrogate for an IQ test, since those are illegal.

It is not illegal to use IQ tests as part of a job screening (in the US). It is illegal to screen in a way that is both discriminatory and not proven to correlate with job performance, but that applies equally to both IQ tests and algorithms questions.

IQ is proven to correlate with performance in virtually everything, so I'm not sure where you're going with that.

If I require all prospective engineering hires to prove explicitly that they have an IQ of at least 135, I will get sued. Do you think this is false?

Re: Harder programming questions do a worse job of predicting outcomes

#424

Post by city41 »

chrshawkes wrote: post #314
city41 wrote: post #207

Earlier quoted context omitted.

At a previous company we interviewed by giving the candidate a choice of a dozen or so problems. All of medium-ish difficulty. Then we together sat at a pairing station and paired on the problem for 2 hours. Candidate can use the internet and anything they want really, as close to real coding as we could make it. Two hours was enough to get into the problem a bit, and get a feel for what they would be like to work wi…

You sit next to the guy the whole time? Eat lunch next to him too? Having some stranger over your shoulder is not real coding either imo.

We had pairing stations, so usually sat at 90 degrees. Each person gets their own desk, monitor, keyboard and mouse. Also this company was huge on pairing, so it was also an indicator of what working there would be like.

Re: Harder programming questions do a worse job of predicting outcomes

#425

Post by sytelus »

If you are asking interview questions that has one beautiful precise answer, you are doing it wrong. Good interview question should start with something very simple that even very beginner can think and answer, then gradually add complexity and constraints little by little.

Example:

1. Write function that multiplies two integers.

2. What if these numbers were real numbers but computer can only operate on integers? How do we use same number of bytes as ints to hold a real number?

3. What if I wanted infinite precision? What would be run time of your algorithm and storage complexity? (don't insist that candidate must hit the known optimal).

4. Can I have complex numbers as well?

5. Imagine complex numbers not only has "i" but also "j" and "k". How do we handle this?

It is astonishing how many candidates won't be able to move past #2.

The key is to look at how candidate approaches handling complexity, create representations and use it to craft clean solutions. Whether they eventually arrive at known optimal/great answers is unimportant.

Re: Harder programming questions do a worse job of predicting outcomes

#426

Post by mikekchar »

toast0 wrote: post #401
mikekchar wrote: post #387

Earlier quoted context omitted.

What I find weird is why does anybody want to work at Google? I use their tools all the time at work. If you go to console.cloud.google.com... I mean... Wow. Just yesterday I was trying to find the logging for our cloud endpoints on Stackdriver. They should use that as their interview question ;-) And this is the big thing I've noticed about many Google apps (especially dev tools): they are all incredibly (for want o…

> What I find weird is why does anybody want to work at Google? I use their tools all the time at work. If you go to console.cloud.google.com... I mean... Wow. Just yesterday I was trying to find the logging for our cloud endpoints on Stackdriver. They should use that as their interview question ;-) Working for Google is the only way to get bugs in Google products fixed, or your feedback even listened to. ;)

I'll be honest, I complained about my total lack of ability to find anything in the documentation and they emailed me back to ask for suggestions on what to fix. I never got back to them. I really should find time.

It was funny because in my frustration, I left a comment on the last page I looked at and they responded with the completely reasonable question, "Why were you looking at that page? It doesn't contain any of the information you were looking for." It was such a great summation of what my problems was that I felt difficulty in finding an appropriate response :-). Possibly this is too unfair, but I felt like the question, "How should I have found the information I was looking for?" was something that had never occurred to them. It's pretty applicable to virtually everything I've used from Google. It has that feel of, "If you don't already know, then you don't deserve to know".

Re: Harder programming questions do a worse job of predicting outcomes

#427

Post by Osiris »

sytelus wrote: post #425

If you are asking interview questions that has one beautiful precise answer, you are doing it wrong. Good interview question should start with something very simple that even very beginner can think and answer, then gradually add complexity and constraints little by little. Example: 1. Write function that multiplies two integers. 2. What if these numbers were real numbers but computer can only operate on integers? Ho…

I couldn't get past #2. Does that mean I'm a bad programmer or just missing the experience for the particular field?

My point is that questions should be tailored to the work the programmer is expected to perform.

Re: Harder programming questions do a worse job of predicting outcomes

#428

Post by TrinaryWorksToo »

gonehome wrote: post #407
TrinaryWorksToo wrote: post #399

Earlier quoted context omitted.

This is exactly what Outco.io does, and I highly recommend them for this purpose.

Looks interesting - have you used them?

Yes! I felt I was noticeably better at selling myself in interviews, which was my primary goal for going through them. I didn't feel I had enough of a support network to properly prepare otherwise. There's a lot of technical stuff, that goes by very quickly, and also equal amount of non-technical, this-is-how-recruiting-works content.

Re: Harder programming questions do a worse job of predicting outcomes

#429

Post by Osiris »

drblast wrote: post #273

Google recruiters call me a lot. I think I'd do a good if not stellar job working there. I've passed multiple FAANG interviews and been very successful as a senior developer. In my email I have an "interview prep packet" from them that essentially tells me to brush up on algorithms and read Cracking the Coding Interview to prepare for their interview process. I'm fairly happy in my job. If they offered more money or…

I don't work in California and it took me a while to figure out what FAANG stands for. Have you guys ever thought that you're just in a bubble that's not representative of the industry as a whole?

Re: Harder programming questions do a worse job of predicting outcomes

#430

Post by HillaryBriss »

mikekchar wrote: post #387
drblast wrote: post #273

Google recruiters call me a lot. I think I'd do a good if not stellar job working there. I've passed multiple FAANG interviews and been very successful as a senior developer. In my email I have an "interview prep packet" from them that essentially tells me to brush up on algorithms and read Cracking the Coding Interview to prepare for their interview process. I'm fairly happy in my job. If they offered more money or…

What I find weird is why does anybody want to work at Google? I use their tools all the time at work. If you go to console.cloud.google.com... I mean... Wow. Just yesterday I was trying to find the logging for our cloud endpoints on Stackdriver. They should use that as their interview question ;-) And this is the big thing I've noticed about many Google apps (especially dev tools): they are all incredibly (for want o…

> why does anybody want to work at Google

with all the android privacy issues researchers keep uncovering, i feel like Google has really driven a certain fraction of the labor pool which cares about protecting user privacy directly away from itself

> they are all incredibly (for want of a better word) hacky.

yeah, i haven't seen much of anything to feel inspired by either (although I do think Google Maps team has put out a really solid product). but i have to deal with the Android SDK and other google libraries for android, and "hacky" seems like the best single word description for that stuff, IMHO, too.

what makes me laugh about the android documentation is that even though Google's mission is to organize the world's information, the best android documentation and guidance i can find is organized by Stack Overflow.

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