Youtube comments of (@ByteByteGo).

  1. Corrections: In the geohash length to grid size mapping table at 15:30 and 20:01, the correct values for 7, 8, 9 and 10 are: 7 152.9m × 152.4m 8 38.2m × 19m 9 4.8m × 4.8m 10 1.2m × 59.5cm
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  2. Subscribe and Kafka will say thank you :)
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  3. Correction: The label at 4:46 should be inter-zone networking, not intra-zone. It is the network round trip between availability zones. The closed caption and verbal explanation are correct.
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  4. Hey Everyone, can you let us know in the comments what topics or types of videos you'd like to see on our channel in the future? Your feedback is greatly appreciated. Thank you!
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  5. Good point. We should have briefly mentioned Python bytecode in the vid, probably towards the end. Thanks for pointing that out - it's an important part of how Python works under the hood.
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  6. Thank you for the questions. For 1, we don't think the exact token specification is that interesting. The payment token is a proxy for the actual card number, and it is tied to the device. The sensitive part is the mapping from the token to the card number, and it is stored in the token service provider. For 2 and 3, if you are interested, look up the EMV contactless specification. It uses cryptography to safeguard the token between the card (in this case, the phone emulating the card) and the card issuer. It is similar to how credit card with a chip works. There's quite a bit of complexity. The general idea is roughly the same as what you suggested.
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  7. If you like what you see, SMASH subscribe. More videos are on the way ❤
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  8. Glad someone noticed it. Appreciate the feedback!
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  9. Subscribe and leave a comment, we read them all :)
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  10. Yes, we will make more system design videos. Those are much longer and take a lot of time to make. Still trying to figure out the right cadence for the longer videos.
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  11. Thanks for the compliment, but we prefer to be paid in memes. A huge shoutout to our amazing video editor for the hard work...
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  12. Like and comment to get your full-stack burger 😃
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  13. Get a Free System Design PDF with 158 pages by subscribing to our weekly newsletter.: https://blog.bytebytego.com
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  14. Animation tools: Adobe Illustrator and After Effects.
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  15. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  16. Subscribe to our weekly newsletter to learn something new every week: http://bit.ly/3JFtDUK
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  17. Thank you. Adobe illustrator and after effects
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  18. Fair point. Update the title to "How Git Works: Explained in 4 Minutes"
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  19. We deal in cold hard cash.
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  20. Thank you for the encouragement. This is the first chapter-length video we made, and it was a lot of work. Your feedback is much apprecated.
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  21. More to come! Do you have any topics in mind?
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  22. What algorithms should we talk about next?
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  23. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. Each video takes many hours to make.
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  24. Not sure if it is simpler. It sounds like a lot of work. 😂 Here's another angle. Many streamers prefer to use their own favorite encoder, with OBS being a prime example. Having our own custom protocol would limit that.
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  25. Adobe After Effects and Adobe Illustrator. Our editors get all the credit, though. :)
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  26. Illustrator and After Effects
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  27. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  28. Great question. Live streaming and video conferencing/calling implementations are quite different. Video conferencing could be an interesting video. The main difference is scale. Living streaming is 1-to-many, where the many could be in the millions. Video conferencing maxes out in the low hundreds, and the experience at that scale is not very good. Also, video conferencing is bi-directional. That imposes a different set of design constraints. To learn more about video conferencing, start with terms like WebRTC, SFU, and MCU.
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  29. We cut out an entire section on how the Apple Pay and Google Pay buttons work that would have answered your question. In short, with the Google Pay button, the Google web server sends the payment token to the web browser, and from the web browser, the token is forwarded to the Payment Service Provider (PSP) for processing. The Apple Pay button only works in Safari on the Mac. As mentioned in the video, the payment token is only stored in the Secure Element on the phone. Once the phone authorizes the web payment, the payment token is sent from the phone to the apple server securely, the apple server re-encrypts the token with the developer's encryption key before sending it from the apple server to the developer (or their payment processor).
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  30. Thanks. Illustrator and After Effects
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  31. At 5:50 it was reading 1GB sequentially from an SSD. Reading 1GB from main memory is at 5:10, which is in the 10-100 ms bucket.
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  32. This is a great question. Let's use Wikipedia's definition of zero copy, which says: "Zero-copy" describes computer operations in which the CPU does not perform the task of copying data from one memory area to another or in which unnecessary data copies are avoided. The "spirit" of zero-copy is to eliminate unnecessary data copies. In Kafka's case, sendfile() does reduce the number of copying. In the best case, if a NIC which supports scatter/gather DMA is used, the copy does not involve the CPU, making it truly zero-copy. There is quite a bit of nuance when it comes to zero-copy. Maybe we can make a video about it down the road.
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  33. You are right. This is a remake of our earlier video with bad audio where people commented "Give this man some money to buy a good mic". 😄
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  34. Thank you for the feedback. We try our best to respect our viewer's time investment in our contents.
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  35. Thank you for the feedback. We did have that initially, but decided to take it out to focus on the LSM tree itself. We knew someone would bring it up, but didn't think it would take this long. 😂 We are glad you did.
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  36. Thank you for the feedback. We agree videos augment text and they could be very useful. The chapter length videos take a lot of efforts to make. We will try to make one once a month, or maybe every two months.
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  37. Send them the bill first. Tell them it would take 10 developer-years. 🤣
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  38. Welcome aboard!
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  39. We don't believe there is a quick answer to these kinds of questions, either. Software engineering is about tradeoffs. We hope to equip our viewers with effective tools in their toolbox to answer these questions in a collaborative manner, both on the job and in the interviews. Good luck.
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  40. Thank you for the question. The label at 4:46 should be inter-zone networking, not intra-zone. It is the network round trip between availability zones. The closed caption and verbal explanation are correct.
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  41. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. Each video takes many hours to make.
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  42. Don’t forget to build it in assembly.
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  43. Thank you for the feedback. At 4:46 it should be inter-zone networking instead of intra-zone. This is the round trip time between availability zones. The illustration is wrong, and the caption and verbal explanation are correct. For reading 1GB sequentially we are on the same page, right?
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  44. That's a good idea. We will definitely do that at some point.
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  45. That is an important part of the overall interview process, too. They are not mutually exclusive. Some companies call that retrospectives, and value them so highly that they prefer to assign their most senior technical leaders to give those interviews when they can.
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  46. Great question. Look up the term "anycast". This is what Cloudflare and GCP use.
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  47. Please subscribe if you learned something new.! Thank you. Tools we use: Adobe after effects and illustrator
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  48. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc...
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  49. Thank you for the suggestion. We will put it on the list. Is there a particular area of CDN you would want to know about?
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  50. Same pace since the beginning in June. Once a week on Tuesday.
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  51. The launch dates in the video refer to the current implementations with payment tokenization for both Apple Pay and Google Pay. The initial Google Wallet launch in 2011 did not use payment tokenization. We agreed it was too subtle and we should've made it more clear. Thank you for bringing this up.
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  52. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. Each video takes many hours to make.
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  53. We respect your viewpoints. Software engineering is about tradeoffs. Some teams might find the high upfront costs worth it.
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  54. Right. We chose 3 precisions in our design, IIRC? The idea is to store at the smallest grid size of the three precisions, and the server could ask the database for the bigger grid sizes by constructing a query using the LIKE operator.
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  55. Adobe After Effects and Adobe Illustrator.
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  56. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator.
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  57. Yes, it is on our list.
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  58. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  59. Very good point. Thank you for pointing it out. We should have said "UDP is simple. It is faster to establish the initial connection than TCP".
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  60. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator.
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  61. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  62. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. It takes many hours for each video.
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  63. Yes, the phone hands the token off to the POS terminal over NFC. There are two contactless standards currently used. EMV contactless is newer and more advanced. It uses something called "cryptogram" to safeguard the information. MSD contactless mimics a magnetic card. It is slightly better than straight magnetic card because the CVV is dynamically generated. Look up EMV and MSD contactless if you would like to learn more.
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  64. Thank you for the feedback. Maybe this is too subtle. This video is more about payment tokenization. It is interesting how Apple got the payment networks and big banks to handle payment tokens directly without passing the primary account number around when processing transactions. When Android first released nfc payments, did it pass the primary account number around, or the payment tokens? The fight between Google and the cell providers is also interesting. This shows up in our research but we decided to leave it out. Thank you for bringing it up.
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  65. Hey, thanks! 🤣
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  66. Google Pay stores the payment token in the wallet app on the device and communicates over NFC with the POS terminal using Host Card Emulation. It does not require an internet connection.
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  67. Yes, SSD. Good catch.
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  68. We do plan to make some videos on system design fundamentals in the future. In the meantime, like others have suggested, write down the terms you don’t understand, do a bit of homework on your own, and don’t hesitate to come back for more questions. We are all beginners on some things and at some point. We have all been there. Hang in there.
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  69. Thank you. Adobe illustrator and after effect.
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  70. We have a private discord server for those who purchased our books or subscribed to our online course at bytebytego.com. The info to join is in the book and online course.
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  71. We have a private discord server for those who purchased our books or subscribed to our online course at bytebytego.com. The info to join is in the book and online course.
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  72. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. Each video takes many hours to make.
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  73. No, but both are UDP-based.
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  74. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator.
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  75. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. Each video takes many hours to make.
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  76. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  77. Ooof... Raft is doable, but Paxos... Can we just do raft, please? LOL
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  78. A simple set's memory requirement scales linearly with the number of elements. A bloom filter's space requirement is capped at the size of the bit-set for the bloom filter itself, which is usually a fraction what a simple set would need. Let's go through an example. Say there is a set with 1 million keys, with each key hashes to a 64-bit number. A simple set would need 8-million bytes to just hold all the keys, ignoring collision handling and other details. A bloom filter with about a 1 in 100 chance of collision would need a bit-set with 10 million bits and 7 hash functions. 10 million bits is 1.25-million bytes. This is the main purpose of a bloom filter. We trade space for sometimes slightly inaccurate answers.
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  79. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  80. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  81. Thank you for the feedback. We’ll definitely make more videos like this. Let us know if you have specific topics you’d like to see.
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  82. That a good one. Great dexterity. 🤣
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  83. Great point. It is really about tradeoffs, isn't it?
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  84. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. Each video takes many hours to make.
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  85. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. Each video takes many hours to make.
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  86. The phone talks to the POS terminal over NFC. Look up EMV contactless if you would like to learn more.
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  87. Many simple system calls like gettimeofday or getpid are processed in the context of the process that invoked it, and do not generally require a context switch to another process.
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  88. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  89. Thank you. No, it's not required. Vol1 and vol2 cover a different set of topics.
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  90. As we mentioned in the previous reply, we encouraged you to look up EMV contactless specification if you want to learn more about how it secures the payment token and its associated information. The idea is very similar to what you are talking about.
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  91. Thank you. This is great feedback. Talking into the camera feels a bit unnatural. Will work on it.
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  92. It should work without internet because the token is stored on device in the wallet app.
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  93. Can you send an email with a brief introduction to hi@bytebytego.com
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  94. We are all learning how to make quality videos as we go. It takes a team. Our editors on illustration and animation are awesome, we have to say...
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  95. 🤜
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  96. What is the latency now, and how low do you need to go?
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  97. If you are referring to the key in 0:46, that is the key to uniquely identify an object (a piece of data). For example, if this is an user object, the key could by a unique user ID, or a unique email address.
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  98. When a user logs in, they supply both user name and password. The user name maps to some internal unique ID. That ID is the primary key of the database table that stores the salt and hash.
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  99. thank you
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  100. 😂 You sure you were only gone for 2 weeks?
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  101. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. Each video takes many hours to make.
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  102. Those are great points. Thank you for your contribution.
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  103. "completely delusional" is a little harsh, don't you think? May we suggest "old school"? 😉 We agree that hard disks are less and less common, but we don't believe they are entirely useless. Last we checked, AWS still offers HDDs that are much cheaper than SSDs, and they are, and we quote AWS, "ideal for frequently accessed, throughput-intensive workloads with large datasets and large I/O sizes, such as MapReduce, Kafka, log processing, data warehouse, and ETL workloads."
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  104. Yes, SSD is much faster than HDD. Cost is the reason to even consider using HDD these days. It could make sense to go HDD if the retention policy is long and/or dataset is huge (like PB scale).
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  105. 🤣🤣
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  106. Thank you for the encouragement. This is hard work, and this is very much appreciated.
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  107. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator.
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  108. The key to an object (or a piece of data or record). Let us know if that is not what you are asking.
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  109. We published two best-sellers on system design interview. We have a 100K+ newsletter on system design. We also have large social followings. We try our best to make quality videos with high signal-to-noise ratio. All these factors help.
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  110. For media attachments, most companies don't keep them forever. There is usually a retention policy on these types of data. In our example, we assumed that the retention policy was 5 years. To calculate the storage requirement for holding the data for 5 years, we multiply the yearly storage requirement by 5. Hope that helps...
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  111. Have to agree. Our editors for the illustration and animation are talented. 🙌
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  112. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. This video is particular took a loooong time to make.
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  113. 🤣
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  114. It's our pleasure. These long videos are hard to make. Your encouragement is much appreciated.
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  115. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  116. We love that guy...
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  117. Could you clarify what a writer is in this scenario? A write is first saved to the memtable, which is usually implemented as some kind of balanced tree. If multiple threads could modify the memtable, then, yes, some locking is required. This is an implementation detail. There are ways to handle incoming write requests that don't need threads or locking, for example, some kind of event queue.
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  118. Good point. English is hard.
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  119. Our talented editors use Adobe Illustrator and Adobe After Effects.
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  120. Good point. Appreciate the clarification.
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  121. Yes, you are right. Thank you for the correction.
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  122. No, not in our two books.
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  123. For live streaming, we believe the answer is yes. Both HLS and DASH are based on HTTP. If and when they are updated to support HTTP/3, then we can probably say that they use UDP, since HTTP/3 uses QUIC and QUIC is built on UDP. We have a video on HTTP/3 and QUIC: https://youtu.be/a-sBfyiXysI
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  124. It takes a team. We have some talented editors for illustration and animation, with the help of tools like Adobe After Effects, Adobe Illustrator, etc. Each video takes many hours to make.
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  125. Do you have specific examples? We did use redis for its other data structures and found it generally to be okay, as long as we pay close attention to the documentation on the big O costs of different operations.
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  126. If you are open to it, please articulate what's missing so we can do better next time.
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