Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Python coding interview challenges

github.com

Post reply on HN
Print view View original

231–240 of 252 posts

Re: Python coding interview challenges

#231

Post by rebootthesystem »

throwaway9475 wrote: post #226
rebootthesystem wrote: post #207

Earlier quoted context omitted.

Not entirely sure how you might have reached that conclusion. Anyone dedicated to their craft will naturally --out of sheer interest-- devote time and effort to getting better at it. For example, as a young EE I was constantly reading data books (yes, physical data books) and application notes. I had hundreds of data books and probably went through all of them twice and some several times. I could, at the time, talk…

So here's the thing: not everyone is you, not everyone is passionate about technology, and it's not reasonable to expect people to do more of their job outside of work for free. You might like, and that's great, but people have families and hobbies and interests that sometimes have nothing to do with the 40 hours they churn through for their bosses. I'm so sick of interviewing for companies who want "passionate" deve…

> not everyone is you, not everyone is passionate about technology, and it's not reasonable to expect people to do more of their job outside of work for free

I am not sure how you would twist personal development and remaining up to date with "do more of their job outside of work for free".

Let's get away from technology for a moment.

You need to go to the doctor.

Would you rather go to a doctor who is passionate about their work and constantly devoting personal time to remain up to date on the latest research, drugs, studies, techniques and technology?

Or would you rather go to a doctor who has not devoted a single day in ten years to stay up to date?

I'd pick option #1 every time. Same with engineers.

Look, if you are not interested in remaining current, that's OK. Just don't expect to have access to the same opportunities. It's as simple as that.

> talk to basically any woman with a job and then rethink your sweet nostalgia

Wow. Not sure how you made the jump to harassment there. Gender has nothing to do with it.

Re: Python coding interview challenges

#232

Post by 35bge57dtjku »

jacquesm wrote: post #118
empthought wrote: post #106

Earlier quoted context omitted.

That's really expensive for the team in terms of time investment for possibly no payoff. Someone has to make sure that a candidate that gets to that point has a good chance of being hired. That person is "your typical interviewer."

Your typical interviewer, if he or she does not have relevant knowledge is just as likely to throw out the baby with the bathwater as they are to select the right candidates. There is no reason not to have the team do the pre-selection. I know this is all terrible news for recruiters and HR people alike but really there is nobody better qualified to determine who they want to work with on a particular problem than th…

> Your typical interviewer, if he or she does not have relevant knowledge is just as likely to throw out the baby with the bathwater as they are to select the right candidates. There is no reason not to have the team do the pre-selection.

What are you talking about? The interviewers are almost always from the team.

> Think about it this way: if you believe that the team you employ is the best possible group to do the work, don't you feel they are also the best possible group to determine how to expand the group?

Yes, and that's why most companies have their devs do interviewing.

Re: Python coding interview challenges

#233

Post by 35bge57dtjku »

NTDF9 wrote: post #175
recursive wrote: post #67

Earlier quoted context omitted.

And how many candidates do you have to consider to find the right one? And what proportion of the interviewer's time is spent on the live coding interview vs setting it up and arranging it? I've been in this boat recently. It doesn't really take much to get to double or even triple digit hours if you don't automate something .

Define "right candidate"? Is right candidate = person who solves algo questions for 5 hours on a whiteboard?

No, it's probably more like 4 1-hour interviews where they do whiteboard coding 2 - 4 times for 30 minutes and the rest of it discussing other previous experience, what they are looking, what the company's doing now and looking to do in the future, etc.

Re: Python coding interview challenges

#234

Post by 35bge57dtjku »

collyw wrote: post #57
andrepd wrote: post #42

Earlier quoted context omitted.

It's not about actually having to implement these algorithms in your practical, day-to-day work. It's a challenge to test your reasoning and problem-solving ability in abstract, that you can administer in 15 minutes. You can't really test a candidate with real-world workloads, can you.

Why not ask me to bring in some work I have and discuss it?

Nothing stops you from discussing your own work. Typically I ask people about past work...

Re: Python coding interview challenges

#235

Post by willchen »

mattfrommars wrote: post #204

Might be slight off topic. But I'm sort of Python enthusiast for a long time but never been able to actually learn how to code. I'm sort of aspiring software developer but a degree in irrelevant engineering. My question is, by studying/doing good amount of Python [currently working on it], going through the entire interview challenges presented here, seeking to gain Master degree in Management Information System [MIS…

It's possible. I got a job as a software engineer at Google despite having a degree in Economics and only knowing Javascript. I spent a lot of time studying data structures & algorithms on my own but it's do-able.

Re: Python coding interview challenges

#236

Post by 35bge57dtjku »

Declanomous wrote: post #185
NTDF9 wrote: post #174

Earlier quoted context omitted.

>> That's like an EE saying, I don't really understand capacitors, but I am building a circuit like this one and it has a capacitor, so I'll just borrow the values and tweak them in simulation. Dude, in EE interviews, we just ask them some basic about capacitor and how to use it. We don't ask them to derive the mathematical equations of electrolytic capacitors. In fact, in most EE interviews, you just use them to sol…

I've never applied for a strictly dev position, but my friends have told me they've been asked about how different forms of self-balancing trees work. I haven't implemented my own self-balancing tree since Data Structures, and I'm pretty sure they haven't either. If someone asked me to implement one in an interview I'd honestly think they were crazy. Who would implement a data structure or algorithm they haven't used…

> If a company really wants to test someone's programming ability in an interview, I feel like the best thing to do would be to make up a programming language, give them a reference sheet, and then ask them to program a couple different versions of fizz-bizz.

Are you joking? Doing fizz-buzz is way too low of a bar. That doesn't even show you can use standard classes and things, like maps and lists.

> but I think you'd at least be testing the skills people actually use when programming

That would tests very few of them, unfortunately.

> rather than whether they can remember every bit of syntax from every language they have listed on their resume

No one I see tests for syntax, but for the more important/broader concepts.

> if I lied and said I knew javascript, I'd almost certainly fail a programming test that used a made-up language based on it.

Probably not. Most mainstream languages have pretty similar syntax. And if you expected people to know others without warning, people would raise hell. Anyone who knows C can probably guess the gist of what a small snippet of non-tricky Javascript does.

Re: Python coding interview challenges

#237

Post by 35bge57dtjku »

logfromblammo wrote: post #110
hashkb wrote: post #90

Earlier quoted context omitted.

No, it's the attitude. Saying "I don't know depth first search" is fine, saying "I'll never need this and by asking it you've revealed what a terrible company you are" is sour grapes.

Not revealed as a terrible company, perhaps, but as a terrible interviewer. If any company were to quiz me on algorithmic basics, it had better explain to me beforehand why it is among the x% of all hiring companies that actually need to roll their own new solutions in the face of so many well-established libraries. That is, before you ask me to demonstrate a depth-first search, you had better explain to me why I'm g…

> If any company were to quiz me on algorithmic basics, it had better explain to me beforehand why it is among the x% of all hiring companies that actually need to roll their own new solutions in the face of so many well-established libraries.

Please suggest a reasonable alternative then. I need to interview people and see if they are going to be capable of digging through complicated code, of coding things reasonably quickly, or writing scalable, robust code, of potentially digging into things enough to optimize their performance, etc. as reasonably well as I can in an hour. And I need enough concrete evidence that everyone else in the debrief believes me. I would love to change the way I do things, but I am held accountable for the interview, so I can't just show up to the debriefs saying crap like, "He says he can use a library for anything that comes up." And I need to evaluate some other soft skills type stuff, like caring about the customer, communicating well, delivering more if you see something extra that you think should be done, etc.

But the obvious answer to your question would be, "because if everything we do could be solved just by using a library, we'd have interns or offshore people do it for a fraction of the pay."

Re: Python coding interview challenges

#238

Post by stuaxo »

35bge57dtjku wrote: post #237
logfromblammo wrote: post #110

Earlier quoted context omitted.

Not revealed as a terrible company, perhaps, but as a terrible interviewer. If any company were to quiz me on algorithmic basics, it had better explain to me beforehand why it is among the x% of all hiring companies that actually need to roll their own new solutions in the face of so many well-established libraries. That is, before you ask me to demonstrate a depth-first search, you had better explain to me why I'm g…

> If any company were to quiz me on algorithmic basics, it had better explain to me beforehand why it is among the x% of all hiring companies that actually need to roll their own new solutions in the face of so many well-established libraries. Please suggest a reasonable alternative then. I need to interview people and see if they are going to be capable of digging through complicated code, of coding things reasonabl…

A huge amount of coding is reading code.

These tests don't test digging through code.

I've worked on projects where people role their own solutions instead of being able to use stuff that's out there and it's not great either.

The real solution I guess is talking to people and teasing this info out of them, and perhaps showing them some older code you have since fixed and seeing what they find in it.

Edit - one reason I personally try and use a lot of libraries is so that large parts of a project are maintained upstream after I leave my contract; the more I write into the project, the more the next dev will have to maintain, anything I can push back into external libraries is a win.

Re: Python coding interview challenges

#239

Post by pc86 »

rebootthesystem wrote: post #211
pc86 wrote: post #127

Earlier quoted context omitted.

> My response to the above would be to have the person bring in some of their work and take an hour or two to take a deep dive into it. So another interview and another day off work? Another set of interview approaches/questions that immediately eliminate people who don't spend their free time doing the same thing they do at work 8+ hours a day? This is not solving the problem.

Sure it does. A huge problem. Here's reality: 100% of the technologies I work with today did not exist when I was in school. The only thing that has remained constant, useful and relevant is basic science, math, physics, etc. What, then, make an engineer a good engineer in any domain? This applies to all aspects of engineering, from software to manufacturing engineering? If I had to pick one thing I'd say their abili…

> If you are looking for quick hires and you are not looking at the idea of adding a team member

> filter them through some quick "can you code this shit fast" puzzles and move on. Great! You are hired. Here's your desk. Here's your ankle chain.

> One is hiring cattle. The other is hiring people.

You seem to be arguing against several points I never made. I took issue with your insinuation that you can just bring someone in for two hours and talk at length about some of their code that they bring it. That cuts out most of the hiring pool, which might be okay if you're Google, but for most companies isn't a smart move at all.

> What I am interested in is someone who has the right approach and attitude for the job, an ability to solve problems creatively and a significant enough desire to learn.

This has no correlation with programming as a hobby or having a wealth of freely reviewable code. Plenty of people love their job, are great at it, very creative, and fantastic technically and never write one line of code that isn't closed source or behind one or more NDAs. They go to work, do an amazing job, then go home after 8 hours and don't write any code or even touch a computer until the next work day.

Re: Python coding interview challenges

#240

Post by prirun »

35bge57dtjku wrote: post #237
logfromblammo wrote: post #110

Earlier quoted context omitted.

Not revealed as a terrible company, perhaps, but as a terrible interviewer. If any company were to quiz me on algorithmic basics, it had better explain to me beforehand why it is among the x% of all hiring companies that actually need to roll their own new solutions in the face of so many well-established libraries. That is, before you ask me to demonstrate a depth-first search, you had better explain to me why I'm g…

> If any company were to quiz me on algorithmic basics, it had better explain to me beforehand why it is among the x% of all hiring companies that actually need to roll their own new solutions in the face of so many well-established libraries. Please suggest a reasonable alternative then. I need to interview people and see if they are going to be capable of digging through complicated code, of coding things reasonabl…

I love this; it's a good insight into what a hiring company wants to know about a potential employee. So how do you get there? Here's my suggestion:

There are 2 very distinct (in my mind) kinds of skills in question. For the "soft skills", a manager-type could and maybe should do that part of the interview. A trusted tech person should do the technical part. I'd go so far to say to that every technical person on the staff should be trained / groomed to help with interviews. So maybe you have 1 tech person do the tech interview, and a 2nd is learning how to interview.

For the interview itself, the process I'd use is to ask a lot of questions. For the soft interview, things like:

- "Tell me about a difficult customer you've had." Let them explain a while, and ask lots of probing questions: "Why didn't you do X instead?", etc.

- "Tell me about a difficult problem you had with a former employer." Same drill.

For the tech part, bring some code to the interview, ask the interviewee to bring some code to discuss. Another option would be to just throw them into a source code tree and say something like "Here's a tree of one of our projects. Talk to me about it." Maybe I'm wrong, but I think I could tell a lot about a tech person just from how they approached being thrown into a mess with no prior information. After all, that's a large part of being a good developer IMO. As they start to figure things out, look at code, etc., ask them questions about what they're seeing. Let them ask too. If you run into something interesting, like a specialized algorithm, ask them about it: "Why do you think it was done this way? What would some other options be?"

Then let them do these things for code they have previously written. For example, I wrote a Prime minicomputer emulator. I'd love an interview where they asked me about why I did this project, what problems I ran into, what were some alternative designs for tricky problems, what were the tricky problems, what did I learn from doing this, what tools did I use to do it, etc.

Post reply on HN