Sahn Lam
@sahnlam
Followers
39K
Following
328
Media
515
Statuses
1K
Coauthor of the Bestselling 'System Design Interview' Series | Cofounder at ByteByteGo | YouTube: https://t.co/IphBm2DLnZ
Join 1,000,000 developers โ
Joined February 2009
How Discord Stores Trillions of Messages. In 2015, Discord started using MongoDB to store messages. By November 2015, there were already 100 million messages that did not fit in RAM, causing unpredictable latency. In 2017, Discord moved to storing billions of messages in a
32
656
4K
Stack Overflow is a multi-tenant monolithic application serving 2 billion monthly page views across 200 sites. Here are some amazing stats:
73
811
4K
1. Session, Cookie, JWT, Token, SSO, and OAuth 2.0 - here's what you need to know. These terms are essential for identifying, authenticating, and authorizing users online. Let's dive in๐
43
625
2K
Understanding OAuth. OAuth is an open standard that allows users to grant limited access to their data on one site to other sites or applications without exposing their passwords. It has become the backbone of secure authorization across the web and mobile apps. The OAuth
9
508
2K
During a major cricket tournament, Disney+ Hotstar captured 5 billion emojis to distill the mood of the 50 million-strong streaming audience in real-time. Curious how they did it? They revealed the design in an engineering blog post [1]. Let's dive in!
26
427
2K
I've used Redis in production for almost a decade. It's reliable and easy to use (if used correctly). Here are my top 5 use cases where it shines:. 1. Caching. The most common use case is to utilize Redis for caching. This helps protect the database layer from overloading. Redis
24
417
2K
Why gRPC is Getting So Popular ๐. gRPC has exploded in popularity for service-to-service communication. Here's why:. - Speed - gRPC is built on HTTP/2 and Protobufs for maximum throughput and minimal latency. Much faster than JSON over HTTP. - Efficiency - The compact Protobuf
19
339
2K
8 key data structures that power modern databases. Which one is your favorite, and why?
12
343
2K
How HTTPS works. HTTPS (Hypertext Transfer Protocol Secure) is a secure way to share information on the internet. It encrypts data transfer between client and server. But without common encryption key, how data is encrypted?. Let's see how:. 1 - Server Certificate Check. -
8
309
2K
Docker vs. Kubernetes. What should we use?. What is Docker?. Docker is an open-source platform that simplifies building, distributing, and running applications using containers. It allows you to create lightweight, portable, self-contained containers from any application, bundled
11
349
2K
I've used Redis in production for almost a decade. It's reliable and easy to use (if used correctly). Here are my top 5 use cases where it shines:
22
281
2K
During a major cricket tournament, Disney+ Hotstar captured 5 billion emojis to distill the mood of the 50 million-strong streaming audience in real time. I revisited this fascinating blog post [1] from 2019 while researching how companies scale real-time updates to tens of
15
277
2K
Key Concepts to Understand Database Sharding. Database sharding refers to splitting data across multiple database servers and is commonly used for scaling. However, sharding introduces major operational and infrastructure complexity that should be avoided until absolutely
10
360
2K
API Pagination Basics. Pagination is a technique to divide large datasets into smaller, more manageable chunks that can be retrieved separately. This improves performance and user experience by preventing huge amounts of data from being loaded at once. There are two common
5
334
2K
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 โก๏ธ HTTP/2 โก๏ธ HTTP/3, and its new UDP-based transport protocol called QUIC.
7
323
2K
Top 4 Forms of Authentication Mechanisms. 1. SSH Keys - cryptographic authentication for secure remote access ๐. SSH keys involve a public and private key pair. The private key is kept secret by the user, while the public key is shared with the remote system. When connecting,
10
351
1K
A Visual Guide to CI/CD. ๐๐ผ๐ป๐๐ถ๐ป๐๐ผ๐๐ ๐๐ป๐๐ฒ๐ด๐ฟ๐ฎ๐๐ถ๐ผ๐ป (๐๐) is a foundational practice in DevOps where developers frequently merge code changes into the main branch, often multiple times a day. This process is complemented by automated testing to ensure new
3
276
1K
Netflix Tech Stack. This post is based on research from many Netflix engineering blogs and open-source projects. If you come across any inaccuracies, please feel free to inform us.
8
194
1K
If you design complex systems, you'll love sequence diagrams. Complex system architectures can quickly become tangled and hard to follow. Enter sequence diagrams! They keep your design neat and easily understandable. For example, check out the diagram below. It depicts a
17
231
1K
How Discord Stores Trillions of Messages. In 2015, Discord started using MongoDB to store messages. By November 2015, there were already 100 million messages that did not fit in RAM, causing unpredictable latency. In 2017, Discord moved to storing billions of messages in a
11
262
1K
Stack Overflow's Impressive Monolithic Architecture. Stack Overflow bucks the microservices trend, handling 1.3 billion monthly pageviews across its 200 sites using a remarkably efficient monolithic architecture with minimal infrastructure. Web Servers:. - Uses only 9 on-prem
17
229
1K
Understanding the API Gateway. An API Gateway is a server that acts as the single entry point for all clients. It provides a unified interface to a set of microservices, simplifies the client-side code, and hides the internal structure of the application. Here is a detailed
5
310
1K
Caching 101: The Must-Know Caching Strategies. Fetching data is slow. Caching speeds things up by storing frequently accessed data for quick reads. But how do you populate and update the cache? That's where strategies come in. ๐ Read Strategies:. Cache Aside (Lazy Loading).-
7
260
1K
Git Merge vs. Rebase vs. Squash Commit. What are the differences and when should you use each? As I explain in more detail in the video, there are some key distinctions. Git Merge. This creates a new commit in the target branch. The new commit ties the histories of both main and
8
305
1K
If you design complex systems, you'll love sequence diagrams. Complex system architectures can quickly become tangled and hard to follow. Enter sequence diagrams! They keep your design neat and easily understandable. For example, check out the diagram below. It depicts a
18
218
1K
Visualizing SQL Queries. A mental model can help visualize how SQL queries are executed. Conceptually, SQL statements can be thought of as executing in this sequence:. 1. FROM: Tables are identified and joined to create the initial dataset. 2. WHERE: Filters are applied to the
5
256
1K
Why is Redis Fast?. Redis is fast for in-memory data storage. Its speed has made it popular for caching, session storage, and real-time analytics. But what gives Redis its blazing speed? Let's explore:. RAM-Based Storage. At its core, Redis primarily uses main memory for storing
4
236
1K
How to improve API performance?. Here are 5 tips:. 1. ๐ฃ๐ฎ๐ด๐ถ๐ป๐ฎ๐๐ถ๐ผ๐ป. Pagination is a common optimization technique when result sets are large. By streaming results back to the client in pages, service responsiveness can be improved. 2. ๐๐๐๐ป๐ฐ๐ต๐ฟ๐ผ๐ป๐ผ๐๐
5
312
1K
You loved my tweet on Stack Overflow's monolith. Now, letโs explore the opposite end of the spectrum: Netflix API architecture evolution. Discover how Netflix API evolved through 4 stages.
18
226
1K
API vs SDK: Key Differences. APIs (Application Programming Interfaces) and SDKs (Software Development Kits) are essential tools for software development, but they serve different purposes:. API:.An API is a set of rules and protocols that allows different software applications
7
305
1K
MVC, MVP, MVVM, MVVM-C, and VIPER. So, let's talk about these software architecture patterns. Each one offers a different approach to organize your code and keep things clean and tidy. MVC - the OG.This classic pattern divides your app into three parts: Model (the data), View
4
311
1K
A Visual Guide to CI/CD. ๐๐ผ๐ป๐๐ถ๐ป๐๐ผ๐๐ ๐๐ป๐๐ฒ๐ด๐ฟ๐ฎ๐๐ถ๐ผ๐ป (๐๐) is a foundational practice in DevOps where developers frequently merge code changes into the main branch, often multiple times a day. This process is complemented by automated testing to ensure new
6
301
1K
Tired of wrangling nested JSON files? This tool is a game-changer.๐. ๐๐ฌ๐จ๐ง๐๐ซ๐๐๐ค generates graph diagrams from JSON files and makes them easy to read. But that's not all: You can also download the diagrams as images for easy sharing. See the link below.
14
202
1K
API vs SDK. An API enables communication between software components, while an SDK provides a set of tools for developing applications on a specific platform.
7
224
1K
We've been making system design videos on YouTube for 6 months and now almost 300K people subscribe to our videos!. Join us: Here are the top 5:
10
179
1K
Git Merge vs. Rebase vs. Squash Commit. What are the differences?. When we ๐ฆ๐๐ซ๐ ๐ ๐๐ก๐๐ง๐ ๐๐ฌ from one Git branch to another, we can use โgit mergeโ or โgit rebaseโ. The diagram below shows how the two commands work. ๐๐ข๐ญ ๐๐๐ซ๐ ๐.This creates a new commit Gโ in the
13
237
1K
Frontend Performance Cheatsheet. โ.Subscribe to our weekly newsletter to get a Free System Design PDF (158 pages):
3
193
1K
Top Architectural Styles. In software development, the architecture you choose plays a key role in shaping a system's structure and behavior. It lays out a blueprint showing how different pieces will fit together to make the software work. Architectural styles offer proven
6
281
1K
Our recommended materials to help you prepare for your next tech interview. You can find the link to watch a detailed video explanation at the end of the post. Coding.- Leetcode.- Cracking the coding interview book.- Neetcode. System Design Interview.- System Design Interview
5
228
1K
A Visual Guide to CI/CD. ๐๐ผ๐ป๐๐ถ๐ป๐๐ผ๐๐ ๐๐ป๐๐ฒ๐ด๐ฟ๐ฎ๐๐ถ๐ผ๐ป (๐๐) is a foundational practice in DevOps where developers frequently merge code changes into the main branch, often multiple times a day. This process is complemented by automated testing to ensure new
4
257
1K
If you design complex systems, you'll love sequence diagrams. Complex system architectures can quickly become tangled and hard to follow. Enter sequence diagrams! They keep your design neat and easily understandable. For example, check out the diagram below. It depicts a
14
152
1K
8 key data structures that power modern databases. Which one is your favorite, and why?. My preference? Definitely B-tree and LSM tree. B-trees and B-tree variants like B+ trees:. - Use on-disk balanced tree structure to enable logarithmic time searches, inserts, deletes.- Used
3
200
1K
How do companies ship code to production?. The following describes a typical software delivery workflow. Companies have diverse environments using different tools. This is one representative workflow that demonstrates some common practices. Details will differ across
22
242
1K
Why is Apache Kafka fast?. There are many design decisions that contributed to Kafkaโs performance. Kafka was originally designed in a time when rotating disks were popular. However, Kafka's design choices still deliver decent performance advantages today. In this post, weโll
7
197
1K
Caching 101: The Must-Know Caching Strategies. Fetching data is slow. Caching speeds things up by storing frequently accessed data for quick reads. But how do you populate and update the cache? That's where strategies come in. ๐ Read Strategies:. Cache Aside (Lazy Loading).-
4
248
1K
How C++, Java, and Python Work Under the Hood?. Compiled languages like C++ and Go transform source code into machine code using a compiler before execution. The compiled machine code can then be directly executed by the CPU. Java first compiles source code into bytecode, which
10
193
1K
API vs SDK. An API enables communication between software components, while an SDK provides a set of tools for developing applications on a specific platform.
6
196
1K
Docker vs. Kubernetes. What should we use?. ๐ช๐ต๐ฎ๐ ๐ถ๐ ๐๐ผ๐ฐ๐ธ๐ฒ๐ฟ?.Docker is an open-source platform that simplifies building, distributing, and running applications using containers. It allows you to create lightweight, portable, self-contained containers from any
4
193
1K
Git can seem confusing at first, but a few key concepts make it clearer:. There are 4 locations for your code:.- Working Directory.- Staging Area.- Local Repository.- Remote Repository (like GitHub). Basic commands move code between these locations.- git add stages changes.- git
6
210
974