SDI References — link changesReferences in System Design Interview: An Insider’s Guide that stopped resolving, came back, or were rewritten.https://sdi.l3.ai/feed.xml2026-08-30T10:46:44ZEpoch — added to the list, already unreachablehttps://sdi.l3.ai/ref/v2-13-11/#2026-08-30T10:46:44Z2026-08-30T10:46:44ZCited in Chapter 13. https://www.epoch101.com/ was added to the list, already unreachable (HTTP 522).Payments Integration at Uber: A Case Study – Gergely Orosz — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v2-11-30/#2026-08-30T10:46:38Z2026-08-30T10:46:38ZCited in Chapter 11. https://www.youtube.com/watch?v=yooCE5B0SRA was added to the list; the host blocks automated checks (HTTP 429).YouTube scalability talk by early YouTube employee — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v1-14-11/#2026-08-30T10:46:36Z2026-08-30T10:46:36ZCited in Chapter 14. https://www.youtube.com/watch?v=w5WVu624fY8 was added to the list; the host blocks automated checks (HTTP 429).Differential Synchronization youtube talk — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v1-15-5/#2026-08-30T10:46:35Z2026-08-30T10:46:35ZCited in Chapter 15. https://www.youtube.com/watch?v=S2Hp_1jqpY8 was added to the list; the host blocks automated checks (HTTP 429).Erasure Coding Demystified — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v2-9-24/#2026-08-30T10:46:34Z2026-08-30T10:46:34ZCited in Chapter 9. https://www.youtube.com/watch?v=Q5kVuM7zEUI was added to the list; the host blocks automated checks (HTTP 429).End-to-end Exactly-once Aggregation Over Ad Streams — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v2-6-17/#2026-08-30T10:46:33Z2026-08-30T10:46:33ZCited in Chapter 6. https://www.youtube.com/watch?v=hzxytnPcAUM was added to the list; the host blocks automated checks (HTTP 429).Geospatial Indexing: The 10 Million QPS Redis Architecture Powering Lyft — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v2-1-29/#2026-08-30T10:46:32Z2026-08-30T10:46:32ZCited in Chapter 1. https://www.youtube.com/watch?v=cSFWlF96Sds&t=2155s was added to the list; the host blocks automated checks (HTTP 429).Weibo video processing architecture (in Chinese) — added to the listhttps://sdi.l3.ai/ref/v1-14-9/#2026-08-30T10:46:31Z2026-08-30T10:46:31ZCited in Chapter 14. https://www.upyun.com/opentalk/399.html was added to the list (HTTP 200).Apache ZooKeeper — added to the listhttps://sdi.l3.ai/ref/v2-12-4/#2026-08-30T10:46:31Z2026-08-30T10:46:31ZCited in Chapter 12. https://zookeeper.apache.org/ was added to the list (HTTP 200).Unicode frequently asked questions — added to the listhttps://sdi.l3.ai/ref/v1-13-5/#2026-08-30T10:46:30Z2026-08-30T10:46:30ZCited in Chapter 13. https://www.unicode.org/faq/basic_q.html was added to the list (HTTP 200).Reliable Processing in a Streaming Payment System — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v2-11-15/#2026-08-30T10:46:30Z2026-08-30T10:46:30ZCited in Chapter 11. https://www.youtube.com/watch?v=5TD8m7w1xE0&list=PLLEUtp5eGr7Dz3fWGUpiSiG3d_WgJe-KJ was added to the list; the host blocks automated checks (HTTP 429).YogabyteDB — added to the listhttps://sdi.l3.ai/ref/v2-11-23/#2026-08-30T10:46:30Z2026-08-30T10:46:30ZCited in Chapter 11. https://www.yugabyte.com/ was added to the list (HTTP 200).Yahoo — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v1-company-engineering-blogs-35/#2026-08-30T10:46:30Z2026-08-30T10:46:30ZCited in Company engineering blogs. https://yahooeng.tumblr.com was added to the list; the host blocks automated checks (HTTP 429).How We've Scaled Dropbox — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v1-15-6/#2026-08-30T10:46:30Z2026-08-30T10:46:30ZCited in Chapter 15. https://youtu.be/PE4gwstWhmc was added to the list; the host blocks automated checks (HTTP 429).Understanding MapReduce in Hadoop — added to the listhttps://sdi.l3.ai/ref/v2-6-19/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 6. https://www.section.io/engineering-education/understanding-map-reduce-in-hadoop/ was added to the list (HTTP 200).QQ Email System Optimization (in Chinese) — added to the listhttps://sdi.l3.ai/ref/v2-8-15/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 8. https://www.slideshare.net/areyouok/06-qq-5431919 was added to the list (HTTP 200).SQLite — added to the listhttps://sdi.l3.ai/ref/v2-12-14/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 12. https://www.sqlite.org/index.html was added to the list (HTTP 200).Global spam volume — added to the listhttps://sdi.l3.ai/ref/v2-8-19/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 8. https://www.statista.com/statistics/420391/spam-email-traffic-share/ was added to the list (HTTP 200).Messenger and WhatsApp process 60 billion messages a day — added to the listhttps://sdi.l3.ai/ref/v1-12-2/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 12. https://www.theverge.com/2016/4/12/11415198/facebook-messenger-whatsapp-number-messages-vs-sms-f8-2016 was added to the list (HTTP 200).Thumbtack — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v1-company-engineering-blogs-33/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Company engineering blogs. https://www.thumbtack.com/engineering was added to the list; the host blocks automated checks (HTTP 403).Consistent hashing — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v2-9-15/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 9. https://www.toptal.com/big-data/consistent-hashing was added to the list; the host blocks automated checks (HTTP 403).Twilio SMS — added to the listhttps://sdi.l3.ai/ref/v1-10-1/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 10. https://www.twilio.com/sms was added to the list (HTTP 200).Scaling Memcache at Facebook — added to the listhttps://sdi.l3.ai/ref/v1-1-7/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 1. https://www.usenix.org/system/files/conference/nsdi13/nsdi13-final170_update.pdf was added to the list (HTTP 200).Yelp — added to the list; robots.txt asks us not to check ithttps://sdi.l3.ai/ref/v2-1-1/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 1. https://www.yelp.com/ was added to the list; robots.txt asks us not to check it.Yelp business endpoints — added to the list; robots.txt asks us not to check ithttps://sdi.l3.ai/ref/v2-1-8/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 1. https://www.yelp.com/developers/documentation/v3/business_search was added to the list; robots.txt asks us not to check it.Microsoft Exchange Conference 2014 Search in Exchange — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v2-8-27/#2026-08-30T10:46:29Z2026-08-30T10:46:29ZCited in Chapter 8. https://www.youtube.com/watch?v=5EXGCSzzQak&t=2173s was added to the list; the host blocks automated checks (HTTP 429).OTP — added to the listhttps://sdi.l3.ai/ref/v2-2-10/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 2. https://www.erlang.org/doc/design_principles/des_princ.html was added to the list (HTTP 200).From nothing: the evolution of WeChat background system (Article in Chinese) — added to the listhttps://sdi.l3.ai/ref/v1-12-8/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 12. https://www.infoq.cn/article/the-road-of-the-growth-weixin-background was added to the list (HTTP 200).Order book — added to the list, already unreachablehttps://sdi.l3.ai/ref/v2-13-12/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 13. https://www.investopedia.com/terms/o/order-book.asp was added to the list, already unreachable (HTTP 402).Geohash — added to the listhttps://sdi.l3.ai/ref/v2-1-17/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 1. https://www.movable-type.co.uk/scripts/geohash.html was added to the list (HTTP 200).Nexmo SMS — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v1-10-2/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 10. https://www.nexmo.com/products/sms was added to the list; the host blocks automated checks (HTTP 403).YouTube by the numbers — added to the listhttps://sdi.l3.ai/ref/v1-14-1/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 14. https://www.omnicoreagency.com/youtube-statistics/ was added to the list (HTTP 200).OpenStreetMap — added to the listhttps://sdi.l3.ai/ref/v2-1-3/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 1. https://www.openstreetmap.org was added to the list (HTTP 200).PagerDuty — added to the listhttps://sdi.l3.ai/ref/v2-5-3/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 5. https://www.pagerduty.com/ was added to the list (HTTP 200).PayPal — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v1-company-engineering-blogs-21/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Company engineering blogs. https://www.paypal-engineering.com was added to the list; the host blocks automated checks (HTTP 403).Queue Length Limit — added to the listhttps://sdi.l3.ai/ref/v2-4-1/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 4. https://www.rabbitmq.com/maxlength.html was added to the list (HTTP 200).A RESTful Tutorial — added to the listhttps://sdi.l3.ai/ref/v1-8-1/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 8. https://www.restapitutorial.com/index.html was added to the list (HTTP 200).Splunk — added to the listhttps://sdi.l3.ai/ref/v2-5-2/#2026-08-30T10:46:28Z2026-08-30T10:46:28ZCited in Chapter 5. https://www.splunk.com/ was added to the list (HTTP 200).A brief introduction to BEAM — added to the listhttps://sdi.l3.ai/ref/v2-2-9/#2026-08-30T10:46:27Z2026-08-30T10:46:27ZCited in Chapter 2. https://www.erlang.org/blog/a-brief-beam-primer/ was added to the list (HTTP 200).Donald J. Patterson, Web Crawling — added to the listhttps://sdi.l3.ai/ref/v1-9-9/#2026-08-30T10:46:27Z2026-08-30T10:46:27ZCited in Chapter 9. https://www.ics.uci.edu/~lopes/teaching/cs221W12/slides/Lecture05.pdf was added to the list (HTTP 200).Why We’re Building Flux, a New Data Scripting and Query Language — added to the listhttps://sdi.l3.ai/ref/v2-5-27/#2026-08-30T10:46:27Z2026-08-30T10:46:27ZCited in Chapter 5. https://www.influxdata.com/blog/why-were-building-flux-a-new-data-scripting-and-query-language/ was added to the list (HTTP 200).Message threading — added to the listhttps://sdi.l3.ai/ref/v2-8-18/#2026-08-30T10:46:27Z2026-08-30T10:46:27ZCited in Chapter 8. https://www.jwz.org/doc/threading.html was added to the list (HTTP 200).LMAX exchange was famous for its open-source Disruptor — added to the listhttps://sdi.l3.ai/ref/v2-13-1/#2026-08-30T10:46:27Z2026-08-30T10:46:27ZCited in Chapter 13. https://www.lmax.com/exchange was added to the list (HTTP 200).US Library of Congress — added to the list; the host blocks automated checkshttps://sdi.l3.ai/ref/v1-9-1/#2026-08-30T10:46:27Z2026-08-30T10:46:27ZCited in Chapter 9. https://www.loc.gov/websites/ was added to the list; the host blocks automated checks (HTTP 403).MySQL — added to the listhttps://sdi.l3.ai/ref/v2-5-10/#2026-08-30T10:46:27Z2026-08-30T10:46:27ZCited in Chapter 5. https://www.mysql.com/ was added to the list (HTTP 200).NYSE matched volume — added to the listhttps://sdi.l3.ai/ref/v2-13-3/#2026-08-30T10:46:27Z2026-08-30T10:46:27ZCited in Chapter 13. https://www.nyse.com/markets/us-equity-volumes was added to the list (HTTP 200).Erlang — added to the listhttps://sdi.l3.ai/ref/v2-2-7/#2026-08-30T10:46:26Z2026-08-30T10:46:26ZCited in Chapter 2. https://www.erlang.org/ was added to the list (HTTP 200).What is avro — added to the listhttps://sdi.l3.ai/ref/v2-6-7/#2026-08-30T10:46:26Z2026-08-30T10:46:26ZCited in Chapter 6. https://www.ibm.com/topics/avro was added to the list (HTTP 200).SSTable — added to the listhttps://sdi.l3.ai/ref/v2-9-17/#2026-08-30T10:46:26Z2026-08-30T10:46:26ZCited in Chapter 9. https://www.igvita.com/2012/02/06/sstable-and-log-structured-storage-leveldb/ was added to the list (HTTP 200).InfluxDB — added to the listhttps://sdi.l3.ai/ref/v2-5-15/#2026-08-30T10:46:26Z2026-08-30T10:46:26ZCited in Chapter 5. https://www.influxdata.com/ was added to the list (HTTP 200).