Explain complex systems with simple terms | Newsletter: blog.bytebytego.com | Author of the bestselling book series: ‘System Design Interview’.

Joined July 2010
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/1 Why is the credit card called “𝐭𝐡𝐞 𝐦𝐨𝐬𝐭 𝐩𝐫𝐨𝐟𝐢𝐭𝐚𝐛𝐥𝐞 product in banks”? How does VISA/Mastercard make money? The diagram below shows the economics of the credit card payment flow. 1. The cardholder pays a merchant $100 to buy a product.
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Next week, we will cover: 🔹Column-based DB 🔹Typical data-intensive architecture 🔹Stack Overflow: The Architecture 🔹SQL optimization tips 🔹Latency numbers you should know (video) Subscribe to the newsletter here: blog.bytebytego.com/
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We are so grateful for the continued support of @getpostman. Learn about their service by visiting bit.ly/3xMFBFe @kinlane, it’s been a pleasure working with you. Would love to co-collaborate some content in the API space. Check out this awesome infographic by Postman.
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Spent 2 hours editing tomorrow's newsletter text so it won’t end up in the promotional folder. Findings. Gmail doesn’t like: - Amazon links - “Also”, “And” in the title - Images that contain YouTube - Word “payment” - Too many headings If you have any tips, please share :)
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If you like gaming, infra, or creator innovation, you might like this podcast as well. Highly recommend it!
Was great to chat with ⁦@DavidBaszucki⁩ about our incredible creator community, technology, and opportunities ahead. linkedin.com/posts/roblox_te…
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/1 Payment through scanning QR code is very common but do you know how many ways there are to do it? There are 4 ways, no matter whether you’re using PayPal, Stripe, Paytm, WeChat, or Alipay. Is this surprising to you? To understand this, we will answer to questions.
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/2 The first question is who presents the QR code: 1. You can present the QR code and the merchant scans the code for payment. This is called ‘consumer-presented mode, and what the merchant does is direct debit your account.
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/3 2. Obviously, the other way is that the merchant presents the QR code for you to scan to pay the due amount. This is called ‘merchant-presented mode’ and you grant the direct credit from your account.
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/4 The second question is whether the QR code is dynamic or static:
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/5 1. A dynamic QR code means the QR code will be generated when you present it, or it will automatically regenerate every few seconds. Because it is dynamically generated, it may contain rich information, such as the amount due, transaction type, etc.
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/6 2. A static QR code is generated once and used everywhere. Usually, it only contains the account information.
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/7 So there are 2*2=4 ways to scan a QR code, which are: 1. Consumer-presented mode + static QR code 2. Consumer-presented mode + dynamic QR code 3. Merchant-presented mode + static QR code 4. Merchant-presented mode + dynamic QR code
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/8 👉 Over to you: I’ve marked one of the scan-to-pay scenarios with a red alert symbol to indicate that a risk is present. Do you know why it is high risk?
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/9 I hope you've found this thread helpful. Follow me @alexxubyte for more. Like/Retweet the first tweet below if you can:
/1 Payment through scanning QR code is very common but do you know how many ways there are to do it? There are 4 ways, no matter whether you’re using PayPal, Stripe, Paytm, WeChat, or Alipay. Is this surprising to you? To understand this, we will answer to questions.
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Alex Xu retweeted
HTTP/3 is hot off the press (published June 2022). It is already supported by many browsers, and a quarter of the top websites. This video explains the progression from HTTP/1 ➡️ HTTP/2 ➡️ HTTP/3, and its new UDP-based transport protocol called QUIC. piped.winscloud.net/a-sBfyiXysI
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/1 Why is Nginx called a “𝐫𝐞𝐯𝐞𝐫𝐬𝐞” proxy? The diagram below shows the differences between a 𝐟𝐨𝐫𝐰𝐚𝐫𝐝 𝐩𝐫𝐨𝐱𝐲 and a 𝐫𝐞𝐯𝐞𝐫𝐬𝐞 𝐩𝐫𝐨𝐱𝐲.
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/2 🔹 A forward proxy is a server that sits between user devices and the internet. A forward proxy is good for: 1️⃣ Protect clients 2️⃣ Avoid browsing restrictions 3️⃣ Block access to certain content
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/3 🔹 A reverse proxy is a server that accepts a request from the client, forwards the request to web servers, and returns the results to the client as if the proxy server had processed the request.
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/4 A reverse proxy is good for: 1️⃣ Protect servers 2️⃣ Load balancing 3️⃣ Cache static contents 4️⃣ Encrypt and decrypt SSL communications Good read: cloudflare.com/learning/cdn/…
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/5 Over to you: What’s the difference between reverse proxy and load balancer? What are some of the most popular proxy servers?
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/6 I hope you've found this thread helpful. Follow me @alexxubyte for more. Like/Retweet the first tweet below if you can:
/1 Why is Nginx called a “𝐫𝐞𝐯𝐞𝐫𝐬𝐞” proxy? The diagram below shows the differences between a 𝐟𝐨𝐫𝐰𝐚𝐫𝐝 𝐩𝐫𝐨𝐱𝐲 and a 𝐫𝐞𝐯𝐞𝐫𝐬𝐞 𝐩𝐫𝐨𝐱𝐲.
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