Custom handwritten notes based on Srini's legendary Backend from First Principles YouTube playlist.
These notes have been requested multiple times by folks on X - so here they are, and if need be can add more such resources :), will keep adding more
Backend from First Principles by Srini is one of the most respected backend engineering series on YouTube. It covers how backend systems are actually built - not just frameworks and tutorials, but the why behind every decision: networking, protocols, databases, concurrency, distributed systems, and more.
This repo contains my personal, handwritten notes made while going through the playlist. They're dense, opinionated, and include my own annotations and aha moments - not just copy-pasted theory.
Work in Progress: Starting with the first 10 parts to gauge interest and feedback. More coming soon!
The notes cover foundational backend concepts including:
- HTTP Protocol - How the web communicates
- Routing - Directing requests to the right handlers
- Serialization & Deserialization - JSON, data formats, and transformations
- Authentication & Authorization - Securing your APIs
- Validation & Transformation - Input handling and sanitization
- Middlewares - Request/response pipelines
- Request Context - Managing state across handlers
- Handlers, Controllers & Services - Code organization patterns
- CRUD Operations - Create, Read, Update, Delete deep dive
- RESTful Architecture - API design best practices
More topics from the full playlist - databases, caching, queuing, scaling, real-time systems, testing, DevOps - will be added based on response.
All notes are provided as PDFs for universal accessibility - you don't need Notability or any specific app to view them.
Part_01_HTTP_Protocol.pdf
Part_02_Routing.pdf
Part_03_Serialization_Deserialization.pdf
Part_04_Authentication_Authorization.pdf
Part_05_Validation_Transformation.pdf
Part_06_Middlewares.pdf
Part_07_Request_Context.pdf
Part_08_Handlers_Controllers_Services.pdf
Part_09_CRUD_Deep_Dive.pdf
Part_10_RESTful_Architecture.pdf
Each PDF contains scanned handwritten notes corresponding to one video from the playlist.
- Engineers preparing for system design interviews (FAANG / big tech)
- Backend developers who want a first-principles mental model, not just syntax
- Students going through the Srini playlist who want a companion reference
- Frontend developers transitioning to backend
- Anyone who learns better by seeing how someone else processed the content
- Watch the playlist first (or alongside): Backend from First Principles - seriously, don't skip this
- Use these notes as a reference - flip back when a concept clicks differently on paper
- Add your own notes - fork the repo and annotate with your own understanding
- If you find gaps or errors, open an Issue or PR - this is a living document
- First 10 parts (foundational concepts)
- Parts 11-20 (databases, BLL, caching, task queuing)
- Parts 21-30 (scaling, concurrency, real-time systems)
- Full playlist coverage
Updates depend on community interest and feedback - star the repo to show support!
Fair warning: my handwriting is... a work in progress. But what matters is the structure and depth of the notes. If something is illegible, open an Issue and I'll clarify or add a typed summary.
- Star the repo so others can find it
- Share it on X / Twitter if you found it useful
- Tag me @yashsj - I'd love to see who's using it!
All conceptual credit goes to Srini for creating one of the best free backend engineering resources on the internet. These are just my personal study notes - not a replacement for watching the series.
- Full Playlist
- Roadmap Video - What the series covers
- Why Learn From First Principles? - Explains the philosophy