Live data from Hacker News

If Richard Feynman applied for a job at Microsoft (2002)

sellsbrothers.com

131–140 of 220 posts

Re: If Richard Feynman applied for a job at Microsoft (2002)

#131
post #14

What an amazing ending! :)

When I worked there in the early 2000's I had a friend of a friend whose fiancée graduated with a bachelor's degree in either CS or EE and applied for a developer position. Somehow, and I struggle to understand the mechanics of this because engineering was highly compartmentalized away from the "business" parts of the business, they managed to turn her down for an engineering role and got her a job in marketing. Also…

>You have a soda machine that has three buttons, Coke, Pepsi, and Random (Coke or Pepsi). You know that your trickster coworker has swapped all of the button labels, so none of them are correct. What's the optimal strategy for getting a Coke out of the machine?

I prefer Pepsi to Coke, so I wouldn't attempt to get a Coke. The optimal strategy is, of course, to get a crowbar, pry the machine open and take what you want.

That's the optimal, least expensive strategy -- assuming you have access to a crowbar.

Re: If Richard Feynman applied for a job at Microsoft (2002)

#132

How many ping pong balls would it take to fill a 747? Why do you ask? What problem are you trying to solve? We want to understand your thought process I'd think it was stupid to fill a 747 with ping pong balls and think about something else

> I'd think it was stupid to fill a 747 with ping pong balls and think about something else This man never heard of a Fermi estimate, or encountered one in a problem set.

It's possible to know what a Fermi problem is and still think that they're bad interview questions.

Re: If Richard Feynman applied for a job at Microsoft (2002)

#133
post #115

Earlier quoted context omitted.

I think it's a rare practice right? "... the theory that those who scored too high could get bored with police work and leave soon after undergoing costly training." I must be a genius. I'm sooo bored at my software dev job. https://abcnews.go.com/US/court-oks-barring-high-iqs-cops/st...

Bored like Peter Gibbons? https://www.youtube.com/watch?v=j_1lIFRdnhA Maybe you need a promotion. https://www.youtube.com/watch?v=af8DVIZ5LX4

There are a lot of good points in there

Re: If Richard Feynman applied for a job at Microsoft (2002)

#134

How many ping pong balls would it take to fill a 747? Why do you ask? What problem are you trying to solve? We want to understand your thought process I'd think it was stupid to fill a 747 with ping pong balls and think about something else

I'm not sure I buy this type of attack. How is this different from calculating yield of a bomb as Fermi did? It's back-of-envelope calculation that physicists do all the time. Ping Pong in a Boeing is merely a setup with the least context. This is like criticizing a math teacher for asking elementary students to calculate how long it takes to fill a swimming pool when water is flowing in and out of the pool at the sa…

There is an interesting point in there about reverse engineering stuff, like you sometimes see in evolutionary biology and such.

Re: If Richard Feynman applied for a job at Microsoft (2002)

#135

How many ping pong balls would it take to fill a 747? Why do you ask? What problem are you trying to solve? We want to understand your thought process I'd think it was stupid to fill a 747 with ping pong balls and think about something else

The real problem with that question isn't that it's stupid. Everyone knows it's stupid, it's testing your ability to come up with an estimate in a domain you're not too familiar with using "napkin math". That's a legitimate skill and asset in software engineering.

The real problem is that the ability to come up with a good napkin math estimate for a technical problem doesn't correlate with the ability to actually do the job to solve the problem.

Ability to estimate doesn't imply engineering/programming skill. You still have to evaluate that part somehow (coding, take home test, github contributions, etc).

It also tells you nothing about the candidate's ability to work with others, under pressure, collaborate in a team, and all sorts of other "behavioural" interview questions.

Once you spent enough time to evaluate someone's behavioural skills, and also their technical skills, you don't have any time left in an hour interview to evaluate their napkin math skills.

Re: If Richard Feynman applied for a job at Microsoft (2002)

#136

It amazes me how defensive, threatened, and snarky people get about interview questions. When leading an interview, do you know how hard it is to tease out if someone is a creative thinker or just a bullshitter? Very hard. You come at it from multiple angles. Sometimes you need questions like this, it is part of the interviewing toolkit along with coding examples, and domain-specific challenges. EDIT: And sometimes y…

Eh, your mileage may vary, but I've normally found too completely open ended questions impossible to ever really get a good signal from. I've done enough interviews to feel like questions with a pretty binary "you either get it or you don't", evaluation make it pretty hard to judge someone. I'd rather ask questions where there are multiple levels of evaluation, rather than a single trick.

Re: If Richard Feynman applied for a job at Microsoft (2002)

#137

How many ping pong balls would it take to fill a 747? Why do you ask? What problem are you trying to solve? We want to understand your thought process I'd think it was stupid to fill a 747 with ping pong balls and think about something else

> I'd think it was stupid to fill a 747 with ping pong balls and think about something else

This is fine as long as you understand that it's equivalent to walking out of the interview right then and there.

Re: If Richard Feynman applied for a job at Microsoft (2002)

#138

How many ping pong balls would it take to fill a 747? Why do you ask? What problem are you trying to solve? We want to understand your thought process I'd think it was stupid to fill a 747 with ping pong balls and think about something else

I'm not sure I buy this type of attack. How is this different from calculating yield of a bomb as Fermi did? It's back-of-envelope calculation that physicists do all the time. Ping Pong in a Boeing is merely a setup with the least context. This is like criticizing a math teacher for asking elementary students to calculate how long it takes to fill a swimming pool when water is flowing in and out of the pool at the sa…

This is fine if the question relates to something that the candidate is familiar with. But I have personally never set foot in a 747, much less be able to come up with any estimate of the dimensions in order to estimate volume. Then there is the formula to determine the packing volume of ping pong balls.

Just like the question of how much water dumps out of the Amazon river per day. Yes, I can write down a formula with a bunch of variables, but there is no way I could justify my guess of what the values of those variables are without some research ahead of time. And in reality, who wants a developer that just starts banging out code without researching the problem domain space first?

In Fermi's case he already knew the inputs such as air resistance, weight of the paper, and of course knew all the relevant math formulas because that was part of his education and job.

Re: If Richard Feynman applied for a job at Microsoft (2002)

#139

It amazes me how defensive, threatened, and snarky people get about interview questions. When leading an interview, do you know how hard it is to tease out if someone is a creative thinker or just a bullshitter? Very hard. You come at it from multiple angles. Sometimes you need questions like this, it is part of the interviewing toolkit along with coding examples, and domain-specific challenges. EDIT: And sometimes y…

tease out if someone is a creative thinker

While I get your point and have been in a similar position myself as the interviewer, the longer I've been working the more I think "creative" is just as much of an overloaded and under-defined term as "smart". These days I just look for the ability to think through complex things methodically, and the creative spark will show itself later, and in place of innate creativity, the ability to churn through lots of ideas when it's needed is a serviceable substitute.

And if by "creative" the interviewers (not necessarily you) mean the ability to come up with novel but compelling ideas, that's something that happens on timescales longer than an interview and certainly not under interview pressure. The people I know who are best at generating novel, compelling ideas do it on the timescales of weeks to months.

Re: If Richard Feynman applied for a job at Microsoft (2002)

#140
post #85

Earlier quoted context omitted.

Maybe I am misunderstanding but the question says NONE of the labels are correct right? If so, I was thinking of it this way. If you press coke, it can only be random or Pepsi (.25?), if you press Pepsi, it can only be coke or random (.75?), if you press random it can only be coke or Pepsi (.5) (oddly this is still random 50/50 :) ). So the optimal on first try would be to press Pepsi?

You press random and taste, lets say it comes out pepsi. This means that this button has to be the pepsi button because if it was the random button then the label would be correct, like you mentioned. This settles the pepsi button. Regarding the other two buttons, one is random and the other is coke but their labels are pepsi and coke, giving us only two possible (order-independent) states which I'll illustrate with…

Both methods are fine.

Let's say you press the Random button first. If it is actually the Coke button, you get a Coke, and you can stop. Otherwise it's actually the Pepsi button, then you press the Pepsi button since that is actually the Coke button. So you get a Coke in one or two button presses.

Basically there are only two permutations of buttons possible, because all other permutations are disqualified by the "not the same as before" rule. Since the goal is specifically to get a Coke in the fewest button presses, you just have to not start with the Coke button since that is the least likely to produce a Coke.

Post reply on HN