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Data science interview questions with answers

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Re: Data science interview questions with answers

#61

Post by Eugeleo »

ryndbfsrw wrote: post #27

I’ve worked in the field for 7 years now so not that long but long enough to build some heuristics. The best data scientists are just people who try to understand the ins and outs of business processes and look at problems with healthy suspicion and curiosity. The ability to explain the nuances of manifolds in SVMs is not something that comes into it outside these contrived interviews. I prefer to ask candidates how…

> The best data scientists are just people who try to understand the ins and outs of business processes and look at problems with healthy suspicion and curiosity

I guess the unsaid part of this is “... and curiosity AND are often able to leverage this in data-driven solutions to bussiness problems”. Because nobody cares whether you’re curious or not if you don’t bring any value to the company. With that said, the part you mentioned almost seems like an innate ability, while the part I filled in could probably be trained.

Suppose you were still in college and wanted to become a data scientist. Based on your current knowledge and values, how would you go about it, being a student? Which skills would you hone and how?

Re: Data science interview questions with answers

#62

Post by waltherg »

y42 wrote: post #32
ryndbfsrw wrote: post #27

I’ve worked in the field for 7 years now so not that long but long enough to build some heuristics. The best data scientists are just people who try to understand the ins and outs of business processes and look at problems with healthy suspicion and curiosity. The ability to explain the nuances of manifolds in SVMs is not something that comes into it outside these contrived interviews. I prefer to ask candidates how…

>> I prefer to ask candidates how they would approach solving a problem Word. Totally off topic, but: I work in the field of information technology since more than 20 years now, more or less. Not always the same focus, not always full time, but always IT related. I consider myself a good problem solver because of my self learning and analytical skills. I recently applied for a job as a BI developer. The interview con…

The - to my mind - most absurd version of this was a well-known Swedish fintech I interviewed with where the one barrier they had set up was one of those online IQ tests (rotating, mirroring etc. blobs on a grid).

I was interviewing for a senior data science role and the other points of contact I had in the process were surprisingly non-technical conversations with a VP of data and another senior data scientist.

Alas, my skills in rotating blobs on a grid failed me that day so that was that.

Re: Data science interview questions with answers

#63

Post by ryndbfsrw »

Eugeleo wrote: post #61
ryndbfsrw wrote: post #27

I’ve worked in the field for 7 years now so not that long but long enough to build some heuristics. The best data scientists are just people who try to understand the ins and outs of business processes and look at problems with healthy suspicion and curiosity. The ability to explain the nuances of manifolds in SVMs is not something that comes into it outside these contrived interviews. I prefer to ask candidates how…

> The best data scientists are just people who try to understand the ins and outs of business processes and look at problems with healthy suspicion and curiosity I guess the unsaid part of this is “... and curiosity AND are often able to leverage this in data-driven solutions to bussiness problems”. Because nobody cares whether you’re curious or not if you don’t bring any value to the company. With that said, the par…

Yes, it’s a given you need to understand what the different techniques are doing and when to apply them, but rarely to the level of depth expected in these white-board interviews that are often just thinly-disguised ways to grill and belittle nervous candidates.

If I could redo my twenties, I would tell myself to choose some topic I cared about, find publicly available data on that topic, and just start exploring the dataset with basic pivot tables and graphs. Ideally write up what you found and publish it somewhere. As you find interesting things in your data you'll naturally start asking more questions and you'll learn modeling techniques as a function of those questions and writing about will help you become a clear communicator (this matters far more than technical knowledge)

Re: Data science interview questions with answers

#64

Post by ryndbfsrw »

Jugurtha wrote: post #37
ryndbfsrw wrote: post #27

I’ve worked in the field for 7 years now so not that long but long enough to build some heuristics. The best data scientists are just people who try to understand the ins and outs of business processes and look at problems with healthy suspicion and curiosity. The ability to explain the nuances of manifolds in SVMs is not something that comes into it outside these contrived interviews. I prefer to ask candidates how…

Diving deep into a domain and interfacing with a subject matter expert goes a long, long, way. We've been building custom data products for enterprise for about seven years, and a lot of the work is listening and grokking large amounts of content about whatever domain we were helping with in general, and the specifics of our clients. Retail, banking, telcos, energy, communication. Having a background in acoustics, re…

>> If you don't and just storm in talking about something something neural nets, they'll see it as a waste of time, won't bother explaining nuances

>> Another major point is specifying the metrics. The real world metrics, not AUC or F1 scores. You need collaboration to get there, too.

>> you need their help getting data, and their expertise to understand it.

All this x100. And it's made worse as this humility isn't taught in schools and rarely asked in data science interviews

Re: Data science interview questions with answers

#65

Post by bonoboTP »

srean wrote: post #53
bonoboTP wrote: post #26

Earlier quoted context omitted.

Interesting and perhaps shows the cultural differences between ML and stats people. I took a machine learning course in my bachelor's and two more ML courses in my master's (CS). These weren't some "deep learning lite", mess-around-in-Keras courses, because DL wasn't even big back then. We covered lots of stuff, Bayesian linear regression, Gaussian processes, Gibbs sampling, Metropolis-Hastings, hierarchical Dirichle…

By tribe I am firmly in the machine learning camp but I have serious doubts that one can be a good hands-on data-science practitioner if one does not have a good foundation in statistics.

Statistics is not really in focus in most CS programs. Indeed I'm not sure where it is. Perhaps in applied math programs. Stats is kinda too dirty and realworld for pure math types, and in science programs and medicine it's usually just taught as a bunch of magic formulas to memorize and rules of thumb passed down from generation to generation without understanding. Perhaps physics departments do have both the necessary math skills and the need for stats so they may provide a good education in this.

But having studied in 3 universities in different countries, CS just doesn't care about stats. Probability theory yes, but frequentist topics like statistical tests not really.

Re: Data science interview questions with answers

#66

Post by teleforce »

For Machine Learning theory related to Data Science I'd highly recommend "The Hundred-Page Machine Learning Book" by Andriy Burkov [1].

According to the author, by reading one hundred pages of the book (plus some extra bonus pages), you will be ready to build complex AI systems, pass an interview or start your own business.

It is a read first book and buy later if you think it is good enough.

[1] http://themlbook.com/

Re: Data science interview questions with answers

#67

Post by jmt_ »

bonoboTP wrote: post #65
srean wrote: post #53

Earlier quoted context omitted.

By tribe I am firmly in the machine learning camp but I have serious doubts that one can be a good hands-on data-science practitioner if one does not have a good foundation in statistics.

Statistics is not really in focus in most CS programs. Indeed I'm not sure where it is. Perhaps in applied math programs. Stats is kinda too dirty and realworld for pure math types, and in science programs and medicine it's usually just taught as a bunch of magic formulas to memorize and rules of thumb passed down from generation to generation without understanding. Perhaps physics departments do have both the necess…

This was my experience at a high ranking engineering public state school in the US. Stats is delegated to the applied math program usually (in fact, my degree was titled "Applied Mathematics & Statistics"). You can choose to concentrate in subjects like algorithms, operations research, fin stuff, statistics, etc. CS as well as other sciences had one required intro to prob & stats, but that's it outside electives.

Further, despite having a fantastic reputation, my program only discussed frequentist ideas with near 0 mention of Bayesian reasoning/methods (outside the same Bayes rule questions asked in the first weeks of every stats class). Overall the education felt too traditional, I would have liked to seen mention of more modern methods like the bootstrap and certainly mention of Bayesian.

Re: Data science interview questions with answers

#68

Post by collyw »

ryndbfsrw wrote: post #64
Jugurtha wrote: post #37

Earlier quoted context omitted.

Diving deep into a domain and interfacing with a subject matter expert goes a long, long, way. We've been building custom data products for enterprise for about seven years, and a lot of the work is listening and grokking large amounts of content about whatever domain we were helping with in general, and the specifics of our clients. Retail, banking, telcos, energy, communication. Having a background in acoustics, re…

>> If you don't and just storm in talking about something something neural nets, they'll see it as a waste of time, won't bother explaining nuances >> Another major point is specifying the metrics. The real world metrics, not AUC or F1 scores. You need collaboration to get there, too. >> you need their help getting data, and their expertise to understand it. All this x100. And it's made worse as this humility isn't t…

Humility is discouraged in software engineering with job ads for ninjas and rock stars.

Re: Data science interview questions with answers

#69

Post by dracyr »

waltherg wrote: post #62
y42 wrote: post #32

Earlier quoted context omitted.

>> I prefer to ask candidates how they would approach solving a problem Word. Totally off topic, but: I work in the field of information technology since more than 20 years now, more or less. Not always the same focus, not always full time, but always IT related. I consider myself a good problem solver because of my self learning and analytical skills. I recently applied for a job as a BI developer. The interview con…

The - to my mind - most absurd version of this was a well-known Swedish fintech I interviewed with where the one barrier they had set up was one of those online IQ tests (rotating, mirroring etc. blobs on a grid). I was interviewing for a senior data science role and the other points of contact I had in the process were surprisingly non-technical conversations with a VP of data and another senior data scientist. Alas…

Yeah, I instantly know which company you're talking about...

I know a couple of developers there and as far as I understood all applicants have to do the IQ test. They also thought it was ridiculous, but the CEO really really likes them, so it stays.

Re: Data science interview questions with answers

#70

Post by kvn_95 »

y42 wrote: post #32
ryndbfsrw wrote: post #27

I’ve worked in the field for 7 years now so not that long but long enough to build some heuristics. The best data scientists are just people who try to understand the ins and outs of business processes and look at problems with healthy suspicion and curiosity. The ability to explain the nuances of manifolds in SVMs is not something that comes into it outside these contrived interviews. I prefer to ask candidates how…

>> I prefer to ask candidates how they would approach solving a problem Word. Totally off topic, but: I work in the field of information technology since more than 20 years now, more or less. Not always the same focus, not always full time, but always IT related. I consider myself a good problem solver because of my self learning and analytical skills. I recently applied for a job as a BI developer. The interview con…

The way I see it, an interview goes both ways. They try to assess your fit in the company, and you're also trying to assess if the company is something you want to spend your time on.

I call this the "game show style" interview. You know the answer, you get $10k. Next question. You didn't know the answer? You're out of the show. Next contestant.

To me this is very disrespectful of your time and your capabilities. Once I was pumped to go into an interview with a very well known company in Sydney, but was dismayed to learn that they do this game show interview (with IQ test, no less!). I wouldn't want to waste my most precious resources (i.e. time) for a company that doesn't respect me.

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