Is this a video course?

No. This is an interactive, slide-based learning platform. Each lesson has rich text, animated diagrams, live code editors, and quizzes. You learn by reading, interacting, and doing, not by watching videos passively.

How long do I have access?

Forever. Both pricing tiers are one-time payments with lifetime access. This includes all current 766 lessons and any future content we add.

What level of experience do I need?

None. We start from absolute basics like 'What is latency?' and build up to distributed consensus protocols. The Foundation level assumes zero prior knowledge of system design.

How much does the system design course cost?

7.99 US dollars for lifetime access globally, or 499 Indian rupees for lifetime access in India. One-time payment, no subscription, no hidden fees. 11 lessons are free with no signup required.

What technologies are covered?

Everything from DNS and load balancers to Kubernetes, Kafka, distributed databases, consensus protocols, stream processing, security architecture, and observability. We cover principles and real-world implementations used at Netflix, Google, Amazon, Uber, Stripe, and more.

Is this useful for system design interview preparation?

Yes. The lessons are structured around the exact topics asked in system design interviews at FAANG and top-tier companies. Interactive diagrams help you practice whiteboard-style explanations. Covers everything from URL shortener design to distributed payment systems.

How is this different from ByteByteGo or Educative?

766 interactive lessons (4x more than most competitors), 16 different diagram types that build step by step, real production examples from Netflix, Google, Amazon, Uber, and Stripe, and lifetime access for a one-time payment of $7.99 instead of annual subscriptions costing 100 to 200 dollars per year.

Why can't you truly 'log out' a user with a pure JWT session (no blocklist)?

The JWT is self-contained and valid until its exp claim, regardless of what the server does, A JWT is a signed, self-contained token. Once issued, it is valid as long as the signature checks out and the exp has not passed. There is no server-side record to delete. Deleting it from localStorage on the client is not a real logout, the token is still valid if the attacker has a copy.

What is the purpose of refresh token rotation?

To detect token theft by invalidating old tokens after each refresh, When a refresh token is used, the server issues a new one and invalidates the old one. If the old token is used again, it means someone else has a copy, which is a theft signal. The server revokes the entire token family, logging out both the attacker and the real user.

An admin demotes a user from 'admin' to 'viewer'. With a 15-minute JWT access token, how long could the user retain admin privileges?

Up to 15 minutes until the access token expires and a new one is issued with updated claims, The JWT contains role: admin embedded at issuance. It will say admin until it expires. When the client refreshes, the auth server checks the database, sees the user is now a viewer, and issues a new JWT with role: viewer. The maximum delay is the access token lifetime (15 minutes).

JWT Sessions

Name: System Design Masterclass
Availability: InStock

in Security Architecture

This lesson is part of the full System Design Masterclass. Unlock it along with 765 other lessons for a one-time payment.

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Foundation lessons free, try before you buy

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India

₹999₹499/lifetime

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Foundation lessons free, try before you buy

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“The interactive diagrams alone are worth way more than the price.”

Anish K., Senior Engineer at a Bengaluru startup

All 766 interactive lessons

Step-by-step animated diagrams

Live code editors with real execution

Quizzes with instant feedback

Completion certificates per level

Lifetime access, all future content included

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