isb's comments

Hey HN,

Many product and data teams have to deal with broken pipelines because analytics events get changed in the tracking code. We built an open source tool to solve this problem. It infers the event schema and monitors changes to it on every pull request. It integrates with Github but you can plug it into other CI/CD systems as well: https://github.com/marketplace/actions/syft-event-analytics-...

We currently support tracking code written in Typescript with Segment, Amplitude, Mixpanel, and Google Analytics SDKs. Please try it out - would love your feedback and contributions (and stars)! Also happy to answers your questions here . Thanks!

Wouldn't it be trivial for msft to filter out responses that include the "rules" verbatim? Which makes me think it is hallucinating.

Yeah, the input processing part is missing but it is fairly trivial. It got most of the other stuff right.

This new model is way better at code generation after testing it on today's Advent of Code problem. I couldn't get Codex to generate a correct solution for part 2 whereas ChatGPT created a correct-looking solution for both parts! Transcript below:

  --- Day 1: Calorie Counting ---
  Santa's reindeer typically eat regular reindeer food, but they need a lot of magical energy to deliver presents on Christmas. For that, their favorite snack is a special type of star fruit that only grows deep in the jungle. The Elves have brought you on their annual expedition to the grove where the fruit grows.

  To supply enough magical energy, the expedition needs to retrieve a minimum of fifty stars by December 25th. Although the Elves assure you that the grove has plenty of fruit, you decide to grab any fruit you see along the way, just in case.

  Collect stars by solving puzzles. Two puzzles will be made available on each day in the Advent calendar; the second puzzle is unlocked when you complete the first. Each puzzle grants one star. Good luck!

  The jungle must be too overgrown and difficult to navigate in vehicles or access from the air; the Elves' expedition traditionally goes on foot. As your boats approach land, the Elves begin taking inventory of their supplies. One important consideration is food - in particular, the number of Calories each Elf is carrying (your puzzle input).

  The Elves take turns writing down the number of Calories contained by the various meals, snacks, rations, etc. that they've brought with them, one item per line. Each Elf separates their own inventory from the previous Elf's inventory (if any) by a blank line.

  For example, suppose the Elves finish writing their items' Calories and end up with the following list:

  1000
  2000
  3000

  4000

  5000
  6000

  7000
  8000
  9000

  10000
  This list represents the Calories of the food carried by five Elves:

  The first Elf is carrying food with 1000, 2000, and 3000 Calories, a total of 6000 Calories.
  The second Elf is carrying one food item with 4000 Calories.
  The third Elf is carrying food with 5000 and 6000 Calories, a total of 11000 Calories.
  The fourth Elf is carrying food with 7000, 8000, and 9000 Calories, a total of 24000 Calories.
  The fifth Elf is carrying one food item with 10000 Calories.
  In case the Elves get hungry and need extra snacks, they need to know which Elf to ask: they'd like to know how many Calories are being carried by the Elf carrying the most Calories. In the example above, this is 24000 (carried by the fourth Elf).

  write a program to Find the Elf carrying the most Calories. How many total Calories is that Elf carrying?

  To solve this problem, we can keep track of the total Calories for each Elf as we read in the input. When we encounter a blank line, we can start a new count for the next Elf. When we have finished reading all of the input, we can find the Elf with the most Calories by looking for the maximum total Calories.

  Here is one possible solution in Python:

  Copy code
  # Read the input
  calories = []
  current_elf = []
  for line in input:
    line = line.strip()
    if line == '':
      # Start a new count for the next Elf
      calories.append(current_elf)
      current_elf = []
    else:
      # Add the Calories to the current Elf's count
      current_elf.append(int(line))

  # Add the last Elf's count
  calories.append(current_elf)

  # Find the Elf with the most Calories
  most_calories = 0
  for elf in calories:
    total_calories = sum(elf)
    if total_calories > most_calories:
      most_calories = total_calories

  # Print the result
  print(most_calories)
  Given the input from the example above, this program would output 24000, which is the correct answer.




  --- Part Two ---
  By the time you calculate the answer to the Elves' question, they've already realized that the Elf carrying the most Calories of food might eventually run out of snacks.

  To avoid this unacceptable situation, the Elves would instead like to know the total Calories carried by the top three Elves carrying the most Calories. That way, even if one of those Elves runs out of snacks, they still have two backups.

  In the example above, the top three Elves are the fourth Elf (with 24000 Calories), then the third Elf (with 11000 Calories), then the fifth Elf (with 10000 Calories). The sum of the Calories carried by these three elves is 45000.

  Write a program to Find the top three Elves carrying the most Calories. How many Calories are those Elves carrying in total?
  To solve this problem, we can modify the solution from Part 1 to keep track of the top three Elves with the most Calories, instead of just the Elf with the most Calories.

  Here is one possible solution in Python:

  Copy code
  # Read the input
  calories = []
  current_elf = []
  for line in input:
    line = line.strip()
    if line == '':
      # Start a new count for the next Elf
      calories.append(current_elf)
      current_elf = []
    else:
      # Add the Calories to the current Elf's count
      current_elf.append(int(line))

  # Add the last Elf's count
  calories.append(current_elf)

  # Find the top three Elves with the most Calories
  top_elves = []
  for elf in calories:
    total_calories = sum(elf)
    if len(top_elves) < 3:
      # Add the Elf to the list of top Elves
      top_elves.append((total_calories, elf))
    else:
      # Sort the top Elves by total Calories
      top_elves = sorted(top_elves, key=lambda x: x[0], reverse=True)
      # If the current Elf has more Calories than the Elf with the
      # least number of Calories among the top Elves, replace that Elf
      if total_calories > top_elves[-1][0]:
        top_elves[-1] = (total_calories, elf)

  # Calculate the total Calories for the top three Elves
  total_calories = sum([x[0] for x in top_elves])

  # Print the result
  print(total_calories)
  Given the input from the example above, this program would output 45000, which is the correct answer.

Some good CS books that I found:

Approximation Algorithms http://link.springer.com/book/10.1007/978-3-662-04565-7

How to Solve It: Modern Heuristics http://link.springer.com/book/10.1007/978-3-662-07807-5

Modern Graph Theory http://link.springer.com/book/10.1007/978-1-4612-0619-4

Computational Geometry http://link.springer.com/book/10.1007/978-3-662-03427-9

Thank you! Since the browsing experience on Springer is not very friendly, here is a link to all the old Springer titles in Amazon's catalog:

Springer: http://www.amazon.com/gp/search/ref=sr_adv_b/?search-alias=s...

Apress: http://www.amazon.com/gp/search/ref=sr_adv_b/?search-alias=s...

This looks very cool. At-least once semantics are the way to go because most tasks require idempotence anyway and that helps in dealing with multiple delivery. Strict FIFO ordering is not always needed either as long as you avoid starvation - most of the time you need "reliable" deferred execution ("durable threads").

I started prototyping something along these lines on top of riak (it is incomplete - missing leases etc but that should be straightforward to add): https://github.com/isbo/carousel It is a durable and loosely FIFO queue. It is AP because of Riak+CRDTs. It is a proof of concept - would be nice to build it on top of riak_core instead of as a client library.

and which book would that be? :)

You can't file for an i-485 if your date is not current which is the case for folks from India/China. So there is no true portability.

I personally enjoyed learning more about the different languages that were used at each level. Granted I'd be meaning to try out node/scala/go in a more meaningful manner and the ctf problems were the perfect setting. The downside to this is that it can be difficult to learn a new language and solve the problem at hand.

I agree level4 was a bit undercooked and not as didactic as it could be. One could simply clear the level by using raft as a black box. Personally I enjoyed level 3 the most given the trade-offs that were present in solving it.

(op here) - I can't edit the link sadly. Should've linked to Jeff's AWS blog post.

Algorithmic interview questions should ideally have multiple solutions of varying complexity. The "brute force" solution should be obvious to anyone competent enough. If they are able to code it up with reasonable clarity and test cases, that is a good start (think of it as the fizzbuzz level). Good candidates should be able to get to the "ideal/aha" solution with some hints. In fact, that process reveals a lot about the candidate. If the candidate doesn't "get" to the ideal solution on their own, it shouldn't be held against them IMO.

In interviews and in general, it usually is a good idea to get a correct yet inefficient solution and then try to optimize it. This usually yields better insights in my experience. Here is a quadratic solution:

https://gist.github.com/isbo/7239007

There are other legal issues too - if you are on a H1B visa, you can't get paid for a try-out period at another company.

This might help - section 4.4 has formal details on the Bind server selection algorithms: http://ocw.mit.edu/courses/mathematics/18-996-topics-in-theo...

I suffer from visual snow and also have floaters. You learn to ignore the static after a while but it is always there if you focus - looking at plain surfaces (e.g. blue sky) makes it very obvious. And as you said, it drastically affects my vision in darkness (think of grainy CCTV footage). I haven't done drugs and don't suffer from migraines which are thought to be correlated. Apparently it is also correlated with Tinnitus but I haven't been able to self-diagnose that.

For the longest time, I wondered if people saw a "static" overlay like I do. Talked to my optometrist about it last time and he wasn't aware of this condition. Googled it later and there is some research starting on the subject: http://www.eyeonvision.org/

You do get extra tax deductions as an international student if your country has a treaty with the U.S. Which countries are completely exempt?

AC-21 portability doesn't come into play until you are almost at the end of the green card process. The long wait is before you get to that stage.

Why can't they apply similar interpretation to legalize re-importation of drugs? The arguments there are similar ( "drugs are expensive in US to subsidize foreign markets").

This is also another blow to the academic publishing racket. In response, they might stop publishing cheap international editions. I hope the availability of high quality open source textbooks and material from MOOCs will cause the developing world to adopt them instead. However, there is a chance that pirated copies - either digital or facsimile copies of US editions - will flood the asian markets. This already happens today but at a small scale.

CloudFront doesn't retry on 500s. Besides, you can't alias to a CloudFront distribution from x.com apex, so I don't think it would work for you even if that were the case.

Route 53 alias feature is RFC compliant - we will return an A record for an apex alias. Aliases can be used at non-apex too to avoid following CNAME chains. So, for e.g., the configuration in docs can be improved upon by having www.example be an alias to example.com instead of a CNAME.