₹0 for students · Certificate · Intermediate

System Design for Freshers

3 mini courses, 12 lessons: building blocks, scaling techniques, and four classic designs worked end to end

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12 lessons · ~2 hours · 24-question final exam · pass mark 70%

About the course

What you’ll learn

How large apps like UPI, food delivery and social feeds are put together, explained for students and freshers. Learn a step-by-step approach to design questions, back-of-the-envelope estimation, APIs and databases, then caching, load balancing, replication, sharding and queues. Finish by designing a URL shortener, a rate limiter, a notification system and a news feed. Pass every lesson quiz and the final exam to earn a verifiable certificate.

System designScalabilityDatabasesCachingAPIs

Part of the career tracks: Web Developer, GenAI and LLM Builder, Computer Science Foundations

How the certificate works

  1. Read each lesson’s study guide, then the full lesson and any notebooks or exercises.
  2. Pass every lesson quiz with 70% or more.
  3. Pass the final exam: 24 questions in 36 minutes.
  4. Get a certificate with a public verification link, and add it to LinkedIn.

Syllabus

12 lessons in 3 mini courses

Each mini course takes about an hour. Already know one? Test out in the app and skip it.

1. Building blocks

Clarify requirements, estimate load and choose APIs and databases.

1
How to Approach a Design Question
12 min · Design questions are open-ended; the thinking is assessed.
2
Clients, Servers and APIs
10 min · Clients talk to servers over HTTP; the API is the contract.
3
Back-of-the-Envelope Estimation
10 min · Daily requests ÷ ~10⁵ seconds ≈ average requests per second.
4
Choosing and Designing Databases
12 min · Relational databases are the default: schemas, joins, ACID transactions.

2. Scaling techniques

Scale a system with caches, load balancers, replicas, shards and queues.

5
Caching
12 min · Caches live in browsers, CDNs, Redis and the database.
6
Load Balancing and Horizontal Scaling
10 min · Many stateless servers behind a load balancer scale horizontally.
7
Replication and Sharding
12 min · Replication copies data; leader takes writes, replicas serve reads.
8
Queues and Asynchronous Work
10 min · Move slow, non-urgent work off the request path into queues.

3. Classic designs

Design four common systems end to end and explain the trade-offs.

9
Design: A URL Shortener
12 min · Functional: shorten, redirect, optional aliases/expiry/clicks.
10
Design: A Rate Limiter
10 min · Rate limiters cap requests per client per window.
11
Design: A Notification System
12 min · Channels: SMS, email, push, in-app; respect preferences and quiet hours.
12
Design: A News Feed
12 min · A feed merges recent posts from followed accounts; reads dominate.

Written by Vikosha. Lessons, questions and exercises are original. Licence: Original Vikosha course..