When I was hiring data scientists for a previous job, my favorite tricky question was "what stack/architecture would you build" with the somewhat detailed requirements of "6 TiB of data" in sight. I was careful not to require overly complicated sums, I simply said it's MAX 6TiB I patiently listened to all the big query hadoop habla-blabla, even asked questions about the financials (hardware/software/license BOM) and…
Plenty of people get offended if you tell them that their data isn’t really “big data”. A few years ago I had a discussion with one of my directors about a system IT had built for us with Hadoop, API gateways, multiple developers and hundreds of thousands of yearly cost. I told him that at our scale (now and any foreseeable future) I could easily run the whole thing on a USB drive attached to his laptop and a few pyt…
Big data is dead (2023)
401–410 of 475 posts
Re: Big data is dead (2023)
#402When I was hiring data scientists for a previous job, my favorite tricky question was "what stack/architecture would you build" with the somewhat detailed requirements of "6 TiB of data" in sight. I was careful not to require overly complicated sums, I simply said it's MAX 6TiB I patiently listened to all the big query hadoop habla-blabla, even asked questions about the financials (hardware/software/license BOM) and…
I gave him the "find the phone numbers in 50,000 html files" question, and he decided to write a huge program with an ad-hoc state machine. When I asked how long it would take to write the program, he said he'd have to hit N files, with M lines per file, so... I interrupted him: no, WRITE. How long to WRITE the program? Oh. He estimated it at 5 days of work. At this point I was 50% ready to throw him out.
Re: Big data is dead (2023)
#403When I was hiring data scientists for a previous job, my favorite tricky question was "what stack/architecture would you build" with the somewhat detailed requirements of "6 TiB of data" in sight. I was careful not to require overly complicated sums, I simply said it's MAX 6TiB I patiently listened to all the big query hadoop habla-blabla, even asked questions about the financials (hardware/software/license BOM) and…
"... or a $199 enterprise HDD" External or internal? Any examples? "... it could be loaded (multimple times) to memory" All 6TiB at once, or loaded in chunks?
Re: Big data is dead (2023)
#404When I was hiring data scientists for a previous job, my favorite tricky question was "what stack/architecture would you build" with the somewhat detailed requirements of "6 TiB of data" in sight. I was careful not to require overly complicated sums, I simply said it's MAX 6TiB I patiently listened to all the big query hadoop habla-blabla, even asked questions about the financials (hardware/software/license BOM) and…
What kind of business just has a static set of 6TiB data that people are loading on their laptops. You tricked candidates with your nonsensical scenario. Hate smartass interviewers like this that are trying some gotcha to feel smug about themselves. Most candidates don't feel comfortable telling ppl 'just load on your laptops' even if they think thats sensible. They want to present a 'professional solution', esp when…
You don't get extra credit points for mind-reading, if anything you get more esteem for requirements-gathering, which would lead you towards either a professional solution or a laptop solution: whichever fits the business needs.
It might be a totally unreasonable question if it's provided context-free as a form on a screen, but it is a perfectly reasonable conversation-starter in an interview.
Re: Big data is dead (2023)
#405Earlier quoted context omitted.
To be fair, mmap doesn't put your data in RAM, it presents it as though it was in RAM and has the OS deal with whether or not it actually is.
Right, which is why you can mmap way more data than you have ram, and treat it as though you do have that much ram. It’ll be slower, perhaps by a lot, but most “big data” stuff is already so god damned slow that mmap probably still beats it, while being immeasurably simpler and cheaper.
For CSV it flat out doesn't matter what you do since the format is so inefficient and needs to be read start to finish, but something like parquet probably benefits from explicit read syscalls, since it's block based and highly structured, where you can predict the read patterns much better than the kernel can.
Re: Big data is dead (2023)
#406Earlier quoted context omitted.
One thing that may have an impact on the answers: you are hiring them, so I assume they are passing a technical interview. So they expect that you want to check their understanding of the technical stack. I would not conclude that they over-engineer everything they do from such an answer, but rather just that they got tricked in this very artificial situation where you are in a dominant position and ask trick questio…
From the point of view of the interviewee, it's impossible to guess if they expect you to answer "no need for big data" or if they expect you to answer "the company is aiming for exponential growth so disregard the 6TB limit and architect for scalability"
Re: Big data is dead (2023)
#407Earlier quoted context omitted.
Is this like interviewing for a chef position for a fancy restaurant and when asked how to perfectly cook a steak, you preface it with “well you can either go to McDonald’s and get a burger, or…” It may not be reasonable to suggest that in a role that traditionally uses big data tools
I’m not sure if you are referencing it intentionally or not, but some chefs (Gordon Ramsey for one) will ask an interviewee to make some scrambled eggs; something not super niche or specialized but enough to see what their technique is. It is a sort of “interview hack” example that’s been used to emphasize the idea of a simple unspecialized skill-test that went around a while ago. I guess upcoming chefs probably prac…
Re: Big data is dead (2023)
#408When I was hiring data scientists for a previous job, my favorite tricky question was "what stack/architecture would you build" with the somewhat detailed requirements of "6 TiB of data" in sight. I was careful not to require overly complicated sums, I simply said it's MAX 6TiB I patiently listened to all the big query hadoop habla-blabla, even asked questions about the financials (hardware/software/license BOM) and…
Re: Big data is dead (2023)
#409Earlier quoted context omitted.
"... or a $199 enterprise HDD" External or internal? Any examples? "... it could be loaded (multimple times) to memory" All 6TiB at once, or loaded in chunks?
https://diskprices.com yields https://www.amazon.com/dp/B0C363Y5BQ , fwiw. (16TB for $129.99 at time of writing)
Re: Big data is dead (2023)
#410When I was hiring data scientists for a previous job, my favorite tricky question was "what stack/architecture would you build" with the somewhat detailed requirements of "6 TiB of data" in sight. I was careful not to require overly complicated sums, I simply said it's MAX 6TiB I patiently listened to all the big query hadoop habla-blabla, even asked questions about the financials (hardware/software/license BOM) and…
Plenty of people get offended if you tell them that their data isn’t really “big data”. A few years ago I had a discussion with one of my directors about a system IT had built for us with Hadoop, API gateways, multiple developers and hundreds of thousands of yearly cost. I told him that at our scale (now and any foreseeable future) I could easily run the whole thing on a USB drive attached to his laptop and a few pyt…
Data organisation can be more of an issue, but the general issue with this is often a lack of internal discipline on the data owners to carefully manage their data. But that isn't nearly as attractive for management. Putting 'brought in new cloud vendor / technology' looks better than 'improved data organisation' on a CV even if the new vendor was a waste of money.