CanvasKeep

Draw. Organize. Version. Never lose a diagram again.

[CanvasKeep @canvaskeep]

Diagrams are easy to create. Keeping track of them? Not so much.

CanvasKeep gives your diagrams a home — folders, projects, and version history so you never lose a version you need.

Free to use. No limits. No credit card.

https://t.co/9CIb039eU0

[Aniruddha @_aniruddha_d]

One tick: the server has it. Two ticks: it reached the phone. Blue: read.

Behind them: a WebSocket per phone, store before ack, Redis pub/sub between chat servers, and an inbox for anyone offline.

System Design in 60s #9: WhatsApp

[Aniruddha @_aniruddha_d]

A million fans tap the same seat. Only one can get it.

Check-then-book double sells it.

The fix: a waiting room, then one atomic write (SET seat NX EX 600) so the first request wins and the hold expires on its own.

[Aniruddha @_aniruddha_d]

Add 1 server to a hash(key) % N cluster and 80% of your keys move.

Consistent hashing puts servers and keys on a ring: each key goes to the next server clockwise, so a new server only takes its own slice. About 1/N of keys move, not most of them.

[Aniruddha @_aniruddha_d]

You tap Request. Uber doesn't give you the closest driver. Here's why:

→ it waits a few seconds to batch nearby riders and drivers
→ it checks real drive times, not distance
→ it pairs everyone for the lowest average wait

Uber says this saves 10 years of waiting a day.

[Aniruddha @_aniruddha_d]

5 Excalidraw tricks most people don't know:

1. Paste Mermaid code, get a hand-drawn diagram
2. Q locks a tool, draw nonstop
3. Ctrl+Alt+C / Ctrl+Alt+V copy and paste styles
4. PNGs exported with "Embed scene" stay editable
5. K is a laser pointer

Which one was new to you?

[CanvasKeep @canvaskeep]

24/7 lofi stream for coding and studying 🌧️
All the music is original. The girl on screen is sketching in @canvaskeep , the whiteboard tool I'm building. Put it on while you work:

https://t.co/zBITXTzf7d

[Aniruddha @_aniruddha_d]

How you'd design Google Docs in a system design interview:

→ editors keep a WebSocket open to a stateless gateway fleet
→ hash(doc_id) routes every editor of a doc to one session server
→ clients send tiny ops, the server transforms concurrent ones (OT)
→ append to the op log BEFORE the ack, then broadcast
→ load = latest snapshot + replay the tail
→ cursors go to Redis with a TTL, never the log

[Aniruddha @_aniruddha_d]

I made a 24/7 lofi stream for coding and studying 🌧️

All the music is original. The girl on screen is sketching in CanvasKeep, the whiteboard tool I'm building.

Put it on while you work:
https://t.co/LicVI0HzP2

[Aniruddha @_aniruddha_d]

Your phone is off. Someone texts you on WhatsApp. Where does the message go?

→ it's encrypted on their phone before it leaves
→ one tick = WhatsApp's server has it, not you
→ the server parks it, still encrypted, for up to 30 days
→ your phone comes back, a push wakes the app
→ the app checks in, the messages flow down, the server deletes its copy
→ two ticks. Open it: blue.

[Aniruddha @_aniruddha_d]

Load balancing in under 60 seconds:

→ one server has a ceiling and a single point of failure
→ put a load balancer in front, add servers
→ round robin: take turns
→ least connections: skip the busy one
→ health checks: dead servers drop out
→ keep sessions in Redis, not in server memory

[Aniruddha @_aniruddha_d]

Opus 5.5 is absolutely cooking with motion design.

[Aniruddha @_aniruddha_d]

Caching in under 60 seconds:

→ check the cache first
→ miss? read the DB, then fill the cache
→ hit? skip the DB entirely
→ writes make it stale: delete on write + a TTL
→ cache full? evict the least recently used key

[Aniruddha @_aniruddha_d]

Design a rate limiter in 60 seconds.

Token buckets, Redis, 429s, and the race condition that lets two requests spend one token.

[Aniruddha @_aniruddha_d]

Built an MCP server so Claude Code can draw diagrams.

One prompt: "create a Coffee Shop workspace and map out opening one." It made the workspace and drew the full flowchart, labeled connections and all.

What would you have Claude diagram first?

[Aniruddha @_aniruddha_d]

Design a URL shortener in 60 seconds.

Key generation, cache-aside, read replicas, and why 302 beats 301 when you want click stats.

[Aniruddha @_aniruddha_d]

I'm 24. Solo founder also working as SDE 2 in an investment banking. Looking to connect with more indie hackers, founders, developers, designers, marketers & AI builders.

just put myself on the map: https://t.co/hzBHFWxe9d

[Aniruddha @_aniruddha_d]

This is cool
https://t.co/t68WA4rs7v

[Aniruddha @_aniruddha_d]

Introducing Canvaskeep MCP

Ask Claude Code (or Codex, or any MCP tool) to draw a diagram - it figures out every box, connection, and label on its own.

[Aniruddha @_aniruddha_d]

Dark mode or Light mode?

[Aniruddha @_aniruddha_d]

Built a launch video for @CanvasKeep using @Remotion
No video editor, no design background. Just code.
Wild what's possible today.