🍔🧠 How Reddit Sends 10M+ Notifications/Month (Deep Dive)
PLUS: Claude AI Best Practices 📋, LLD Interview Blueprint 📘, CDN Explained 🌍
Happy Monday! ☀️
Welcome to the 175 new hungry minds who have joined us since last Monday!
If you aren’t subscribed yet, join smart, curious, and hungry folks by subscribing below.
📚 Software Engineering Articles
Master these 7 must-know patterns for system design interviews
Built a React framework 4x faster than Next.js
5 proven techniques to write maintainable code that lasts
Learn these LLM terms explained in simple English
HTTP complexity revealed: beyond the basics
🗞️ Tech and AI Trends
AWS CEO slams AI replacing juniors as "dumbest idea"
Waymo gets permit to test self-driving cars in NYC
Meta freezes AI hiring amid market concerns
👨🏻💻 Coding Tip
Use awk with custom field separators to extract data from logs
Phoenix.new: The fastest way to build Elixir apps in-browser
No more tedious setup.
Phoenix.new builds full-stack, real-time Elixir apps with an AI agent, right in your browser.
Spin up a full dev environment, test with a headless browser, see live previews, and deploy to Fly.
GitHub included.
Local optional.
How Reddit delivers notifications to tens of millions of users 🤳
Reddit built a sophisticated notification system that processes millions of posts daily to deliver personalized push notifications at scale. The system combines causal modeling, real-time retrieval, and deep learning to ensure users receive relevant content without notification fatigue.
The challenge: Balance user engagement with notification fatigue while processing millions of posts in real-time and maintaining high personalization accuracy.
Implementation highlights:
Smart budgeting: Uses causal modeling to determine optimal daily notification limits per user
Two-tower retrieval: Implements fast candidate selection using embedding-based similarity matching
Multi-task learning: Employs deep neural networks to predict multiple engagement signals simultaneously
Dynamic reranking: Applies product-driven adjustments to maintain content diversity and freshness
Queue-based architecture: Ensures reliable delivery through asynchronous processing pipeline
Results and learnings:
Achieved real-time processing of millions of daily posts
Maintained high user engagement while minimizing notification fatigue
Successfully scaled to tens of millions of users with personalized delivery
Reddit's approach shows that building effective notification systems requires more than just technical prowess - it needs deep understanding of user behavior and engagement patterns. Their multi-stage pipeline demonstrates how to balance ML sophistication with practical product needs.
The 7 Must Know Patterns for System Design Interviews
Written by
7 Principles of Solution Architecture Design You Should Know
Developers, Reinvented
What started as fear of AI replacing developers is switching to pragmatically embracing the ambitious reality of AI and viewing it as a growth opportunity.
I Created the most Comprehensive LLD Interview Resource
Written by
5 Tiny Phrases Every Engineer Should Use With AI
Written by
LLMs: Common terms explained, simply
Written by
Why I switched from Cursor to Claude Code
Written by
5 Things in Data Engineering That Still Hold True After 10 Years
Written by
ESSENTIAL (http-drama-queen)
HTTP is not simple
ARTICLE (retro-magic)
How to Run Great Retrospectives
ARTICLE (context-wizardry)
2025 guide to Context Engineering for Software Engineers
ARTICLE (cdn-secrets)
A Critical Guide to Content Delivery Networks
ARTICLE (money-for-code)
The Pulse #143: Creative ways to fund open source projects
ARTICLE (cloud-brain-food)
EP03: Essential Reading for Cloud Builders
ARTICLE (oauth-dance)
How to implement OAuth for MCP Server
ARTICLE (code-whisperer)
5 Proven Techniques for Readability and Maintainability
GITHUB REPO (agent-overlords)
LLM agents built for control. Designed for real-world use. Deployed in minutes.
ARTICLE (need-for-speed)
How I Built a Full-Stack React Framework 4x Faster Than Next.js With 4x More Throughput
Want to reach 190,000+ engineers?
Let’s work together! Whether it’s your product, service, or event, we’d love to help you connect with this awesome community.
🤖 AWS CEO Slams AI Replacing Junior Staff as 'Dumbest Idea' (2 min)
Brief: AWS CEO Matt Garman calls replacing junior employees with AI "the dumbest thing," arguing they’re cost-effective and key to future skill development, while advocating for AI as a tool for learning, not replacement.
🤖 AWS CEO Calls AI Replacement of Junior Staff ‘Dumbest Idea Ever’ (3 min)
Brief: AWS CEO Matt Garman slams the idea of replacing junior employees with AI, arguing they’re cost-effective and critical for long-term skill development, while advocating for AI as a training tool instead.
🤖 AGENTS.md: The Standard File for AI Coding Assistants (2 min)
Brief: AGENTS.md is emerging as the standardized Markdown file for AI coding agents, providing project-specific instructions to complement traditional READMEs and streamline collaboration between developers and AI helpers.
⚠️ Zuckerberg Freezes Meta’s AI Hiring Amid Bubble Fears (2 min)
Brief: Meta halts AI hiring after market turmoil and concerns over overinvestment, reversing its aggressive talent acquisition strategy that included $1B offers to top researchers.
🚖 Waymo Gets Green Light for NYC Robotaxi Operations (2 min)
Brief: Waymo secures critical permits to launch commercial autonomous rides in New York City, marking Alphabet's first robotaxi expansion to a dense urban environment.
This week’s coding challenge:
This week’s tip:
Use awk pattern matching with custom field separators to extract structured data from messy logs using Extended Regular Expressions (ERE). The -F flag sets field separators, while pattern blocks like /pattern/{action} filter lines before processing.
Wen?
Legacy system analysis: Parse inconsistent log formats without writing custom parsers.
Quick data extraction: Pull specific fields from JSON-like logs without full parsing overhead.
Real-time monitoring: Filter and transform log streams on-the-fly in monitoring pipelines.
“We cannot change anything unless we accept it.”
Carl Jung
That’s it for today! ☀️
Enjoyed this issue? Send it to your friends here to sign up, or share it on Twitter!
If you want to submit a section to the newsletter or tell us what you think about today’s issue, reply to this email or DM me on Twitter! 🐦
Thanks for spending part of your Monday morning with Hungry Minds.
See you in a week — Alex.
Icons by Icons8.
*I may earn a commission if you get a subscription through the links marked with “aff.” (at no extra cost to you).