iiinova — where your digital self keeps evolving

Neo Kim @systemdesign.one · 08/05/2025

Here are some probabilistic data structures you must know as a software engineer (not kidding): They trade accuracy for space efficiency. They're often used in: • Databases • Cache • Search engines • Network infrastructure • Analytics What else should make this list?

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Neo Kim @systemdesign.one · 05/05/2025

If you want to reduce latency, learn these 12 rules:

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Neo Kim @systemdesign.one · 02/05/2025

👋 PS - I wrote a more detailed article about DNS in my newsletter (with visuals): → newsletter.systemdesign.one/p/what-is-a-dns-server-and-how-does-it-work

newsletter.systemdesign.one

How DNS Works 🔥

#70: Distributed Hierarchical Database for 5.35B Users (2 Minutes)

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Neo Kim @systemdesign.one · 02/05/2025

Give me 2 mins and I'll teach you how DNS works:

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Neo Kim @systemdesign.one · 14/04/2025

Meta achieves 99.99999999% cache consistency. Here’s how they do it (in 2 minutes): —— 👋 PS - I put together a detailed case study with visuals in my newsletter: → newsletter.systemdesign.one/p/cache-cons...

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Neo Kim @systemdesign.one · 11/04/2025

Give me 2 mins and I'll teach you how Disney+ Hotstar scaled to 25M concurrent users—no fluff:

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Neo Kim @systemdesign.one · 10/04/2025

How I’d scale a site to 1 million users—step by step:

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Neo Kim @systemdesign.one · 08/04/2025

Hey, it's a pleasant surprise to see you on bsky

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Neo Kim @systemdesign.one · 07/04/2025

HTTP status codes you must know as a web developer in 2025: Status codes are 3-digit numbers returned by a server in response to HTTP requests. It tells the client about the request status and indicates problems if any. So understanding status codes will help you find site errors quickly.

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Neo Kim @systemdesign.one · 06/04/2025

This lady: • Has no tech background • Couldn't draw well as a kid • Knew nothing about venture capitalists Yet she's worth $5.8 Billion - at 37.

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Neo Kim @systemdesign.one · 02/04/2025

How to write clean code. The KYD-DTC Playbook:

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Neo Kim @systemdesign.one · 01/04/2025

Give me 2 mins and I'll teach you how a database stores passwords securely (not kidding):

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Neo Kim @systemdesign.one · 29/03/2025

Give me 2 mins and I'll teach you how Amazon S3 (actually) works:

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Neo Kim @systemdesign.one · 27/03/2025

👋 PS - I wrote an article with visuals about this case study in my newsletter: → newsletter.systemdesign.one/p/how-does-a...

newsletter.systemdesign.one

How Apple Pay Handles 41 Million Transactions a Day Securely 💸

#68: Break Into Apple Pay Architecture (5 Minutes)

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Neo Kim @systemdesign.one · 27/03/2025

I spent hours studying how Apple Pay works, so you don't have to. Here's what I learned distilled into 9 sentences:

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Neo Kim @systemdesign.one · 24/03/2025

• Google Drive → Nextcloud • Microsoft Outlook → Thunderbird • LastPass → KeePass • YouTube → PeerTube • Adobe Premiere Pro → Kdenlive • Visual Studio → Vim • Trello → Taiga • Evernote → Joplin

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Neo Kim @systemdesign.one · 24/03/2025

Popular apps and open-source alternatives: What else should make this list? • Microsoft Office → Libre Office • WhatsApp → Signal • Google Chrome → Mozilla Firefox • Adobe Photoshop → Krita • Google → DuckDuckGo • Windows / Mac → GNU Linux

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Neo Kim @systemdesign.one · 23/03/2025

Give me 2 minutes and I'll teach you how YouTube supports 2.49 billion users with MySQL (not kidding):

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Neo Kim @systemdesign.one · 22/03/2025

I spent hours studying how Amazon S3 achieves 99.999999999% durability — because S3 is the new norm. Here's what I learned distilled into 12 sentences (not kidding):

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Neo Kim @systemdesign.one · 21/03/2025

Git has 152 commands. But most people don't know the powerful ones. Here are the 4 must learn Git commands (bookmark this):

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Neo Kim @systemdesign.one · 20/03/2025

Give me 2 minutes, and I'll teach you how Uber computes ETA (not kidding):

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Neo Kim @systemdesign.one · 19/03/2025

I spent hours studying how Amazon Lambda works — because Serverless is the new norm. Here's what I learned distilled into 11 sentences (you'll thank me later):

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Neo Kim @systemdesign.one · 18/03/2025

♻ Repost to help others learn system design ➕ Follow @systemdesign.one

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Neo Kim @systemdesign.one · 18/03/2025

13 How Zoom Works ↳ newsletter.systemdesign.one/p/zoom-archi... 14 How Meta Achieves 99.99999999% Cache Consistency ↳ newsletter.systemdesign.one/p/cache-cons... 15 How to Scale an App to 10 Million Users on AWS ↳ newsletter.systemdesign.one/p/aws-scale

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Neo Kim @systemdesign.one · 18/03/2025

11 How Tinder Scaled to 1.6 Billion Swipes per Day ↳ newsletter.systemdesign.one/p/tinder-arc... 12 URL Shortener System Design ↳ systemdesign.one/url-shorteni...

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Neo Kim @systemdesign.one · 18/03/2025

9 Distributed Counter Architecture ↳ systemdesign.one/distributed-... 10 Pastebin System Design ↳ systemdesign.one/system-desig...

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Neo Kim @systemdesign.one · 18/03/2025

7 How Cloudflare Handles 55 Million RPS With Only 15 Postgres Clusters ↳ newsletter.systemdesign.one/p/postgresql... 8 Slack System Design ↳ systemdesign.one/slack-archit...

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Neo Kim @systemdesign.one · 18/03/2025

5 How Uber Computes ETA at 0.5 Million Requests per Second ↳ newsletter.systemdesign.one/p/uber-eta 6 Gaming Leaderboard System Design ↳ systemdesign.one/leaderboard-...

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Neo Kim @systemdesign.one · 18/03/2025

3 How Stripe Prevents Double Payment Using Idempotency ↳ newsletter.systemdesign.one/p/idempotent... 4 How YouTube Was Able to Support 2.49 Billion Users With MySQL ↳ newsletter.systemdesign.one/p/vitess-mysql

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Neo Kim @systemdesign.one · 18/03/2025

1 How Uber Finds Nearby Drivers at 1 Million Requests per Second ↳ newsletter.systemdesign.one/p/how-does-u... 2 How Amazon S3 Achieves 99.999999999% Durability ↳ newsletter.systemdesign.one/p/amazon-s3-...

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Neo Kim @systemdesign.one · 18/03/2025

If you want to become good at system design (I'm not joking), learn these case studies:

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Neo Kim @systemdesign.one · 17/03/2025

14 Redis use cases you must know as a software engineer (bookmark this): What else should make the list?

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Neo Kim @systemdesign.one · 16/03/2025

Bad vs Good Software Engineers What else should make this list?

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Neo Kim @systemdesign.one · 15/03/2025

♻ Repost this thread to help others learn system design ➕ Follow @systemdesign.one

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Neo Kim @systemdesign.one · 15/03/2025

The system stores videos and playlists in an object storage, such as AWS S3 While videos are cached in CDN to reduce costs and network usage What else would you add?

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