System Design Hands-On · by Roni Das

Real systems, built live, line by line

Long builds where a real system goes up on one laptop, every command typed live and every number measured on screen. You watch a database struggle, then fix it the way production teams do. The builds come with the System Design course, at no extra cost.

2h 36mof live code

20chapters

139slide pages

15mfree to watch

Watch the free preview See the chapters

build 1: the shards you will run on your own laptop

How a hands-on build works

One system, start to finish

Not a slide talk. A real system goes up in Docker on one laptop, you load it until it breaks, and you fix it step by step.

Typed live, measured live

Every line is typed and explained as it goes in. Every number on screen was printed by a real terminal, so you see what each fix is worth.

The code and the slides

The full code is on GitHub, free. Course members also get the slide deck for every chapter: the diagrams, the commands and the measured numbers.

The builds

Each build opens with a free preview. The full build and its slides come with the System Design course.

Postgres Sharding: an app and a router in front of four PostgreSQL shards

2 h 36 min20 chapters139-page slide deckfirst 15 min free

Postgres Sharding: Complete Hands-On (PgBouncer + Citus)

Load one PostgreSQL until it breaks, shard it yourself with a router you write, then add PgBouncer and Citus. Every number measured live.

PostgreSQL 17DockerPythonPgBouncerCituspgAdmin

Watch the free 15 minutes Unlock with the course · ₹499 · $49

chapter list

0:000Teaser: what we will buildfree
1:181What sharding is, why and when you need it, and what it costsfree
7:062How enterprises run a databasefree
13:113Meet KiranaLoop: build the orders databasefree
14:443aBefore you start: Docker Desktop, VS Code, the code
19:123bIs PostgreSQL running? psql and pgAdmin
24:593cThe app container and the first tables
40:064Measure it: orders per second, p95, the slow second
1:01:145Climb the ladder: a replica, and partitioning by month
1:12:126Choose the shard key from the queries
1:19:297Four ways to split the data
1:21:158Four shards and a router
1:38:429The dashboard that asks every shard
1:45:0210The 9 pm flash sale
1:56:4211Too many connections, and the pool that fixes it
2:05:0212A fifth shard: the belt, the ring road, and buckets
2:14:3013What sharding makes hard
2:17:1914The enterprise way: Citus, and how others do it
2:31:4015Should you shard? The checklist and the interview answer
2:34:3415aClean up your laptop

Free: chapters 0, 1, 2, 3. The rest come with the System Design course.

Coming next

Being built now. No dates until each one is finished and checked.

in the works

Redis caching under real load

Cache-aside, a stampede on one hot key, and eviction, measured on your laptop.

in the works

Kafka: an event pipeline end to end

Producers, partitions, consumer groups and a replay, built and broken live.

in the works

A rate limiter in production

Token bucket and sliding window in front of a real API, then the same limits shared across servers.

Every build comes with the System Design course

One payment for the course gives you every lesson, the AI tutor, and every hands-on build on this page with its slides.

₹499 · $49Get the System Design course What is in the course

System Design Hands-On · by Roni Das

Real systems, built live, line by line

2h 36mof live code

20chapters

139slide pages

15mfree to watch

Watch the free preview See the chapters

build 1: the shards you will run on your own laptop

How a hands-on build works

One system, start to finish

Not a slide talk. A real system goes up in Docker on one laptop, you load it until it breaks, and you fix it step by step.

Typed live, measured live

Every line is typed and explained as it goes in. Every number on screen was printed by a real terminal, so you see what each fix is worth.

The code and the slides

The full code is on GitHub, free. Course members also get the slide deck for every chapter: the diagrams, the commands and the measured numbers.

The builds

Each build opens with a free preview. The full build and its slides come with the System Design course.

2 h 36 min20 chapters139-page slide deckfirst 15 min free

Postgres Sharding: Complete Hands-On (PgBouncer + Citus)

Load one PostgreSQL until it breaks, shard it yourself with a router you write, then add PgBouncer and Citus. Every number measured live.

PostgreSQL 17DockerPythonPgBouncerCituspgAdmin

Watch the free 15 minutes Unlock with the course · ₹499 · $49

chapter list

0:000Teaser: what we will buildfree
1:181What sharding is, why and when you need it, and what it costsfree
7:062How enterprises run a databasefree
13:113Meet KiranaLoop: build the orders databasefree
14:443aBefore you start: Docker Desktop, VS Code, the code
19:123bIs PostgreSQL running? psql and pgAdmin
24:593cThe app container and the first tables
40:064Measure it: orders per second, p95, the slow second
1:01:145Climb the ladder: a replica, and partitioning by month
1:12:126Choose the shard key from the queries
1:19:297Four ways to split the data
1:21:158Four shards and a router
1:38:429The dashboard that asks every shard
1:45:0210The 9 pm flash sale
1:56:4211Too many connections, and the pool that fixes it
2:05:0212A fifth shard: the belt, the ring road, and buckets
2:14:3013What sharding makes hard
2:17:1914The enterprise way: Citus, and how others do it
2:31:4015Should you shard? The checklist and the interview answer
2:34:3415aClean up your laptop

Free: chapters 0, 1, 2, 3. The rest come with the System Design course.

Coming next

Being built now. No dates until each one is finished and checked.

in the works

Redis caching under real load

Cache-aside, a stampede on one hot key, and eviction, measured on your laptop.

in the works

Kafka: an event pipeline end to end

Producers, partitions, consumer groups and a replay, built and broken live.

in the works

A rate limiter in production

Token bucket and sliding window in front of a real API, then the same limits shared across servers.

Every build comes with the System Design course

One payment for the course gives you every lesson, the AI tutor, and every hands-on build on this page with its slides.

₹499 · $49Get the System Design course What is in the course