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.

A user checks their order status and sees 'shipped'. They refresh and see 'processing'. What consistency guarantee was violated?

Monotonic reads, because the user saw a newer value followed by an older one, The user saw 'shipped' (newer) then 'processing' (older). Monotonic reads guarantees that once you see a value, you never see something older. The second read hit a lagging replica that had not yet applied the status update.

Sticky sessions guarantee monotonic reads by pinning clients to one replica. What breaks this guarantee?

The pinned replica fails and the load balancer rehashes to a different, potentially lagging replica, When the pinned replica dies, the LB sends the client to a different node. If that node is behind on replication, the client sees older data than what the dead replica had served. Version tokens survive this because the guarantee lives in the data, not the routing.

MongoDB's clusterTime mechanism provides monotonic reads. How does it work?

Each response carries a clusterTime. The driver sends it with the next read. The shard waits until its applied time reaches that value before responding., MongoDB attaches a hybrid logical clock value (clusterTime) to every response. The driver tracks the max value per session. Subsequent reads carry afterClusterTime, and the target shard blocks until its own applied time is at least that high. This works across failover because any caught-up shard can serve.

A user opens your app in two browser tabs with separate session IDs. Tab 1 sees balance $500. Tab 2 sees balance $480. Is this a monotonic reads violation?

No. Monotonic reads is per-session. Each tab has an independent session with its own version history., Monotonic reads guarantees that within a single session, values never go backwards. Two separate sessions have independent guarantees. To unify them, promote the version token from session-level to account-level, as Facebook's TAO does with user-level read guards.

Monotonic Reads

Name: System Design Masterclass
Availability: InStock

in Consistency Models

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