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 PostgreSQL cluster uses Patroni for active-passive failover. The primary dies and the standby is promoted. What is the most likely failover time?

10 to 30 seconds, Patroni detects the primary failure via DCS (etcd/Consul), promotes the standby which replays any remaining WAL segments, and updates the service endpoint. The entire sequence completes in 10 to 30 seconds for a well-configured cluster.

After a successful failover, the original primary recovers. The team wants to fail back. What is the correct first step?

Reverse the replication direction so the recovered primary catches up from the current primary before shifting any traffic, The current primary has accumulated writes during the outage. The recovered primary must catch up via reversed replication before receiving any traffic. Shifting traffic without catching up causes data loss or split brain.

Why is active-passive preferred over active-active for relational databases?

Relational databases require a single writer to maintain transactional consistency, and active-passive guarantees exactly one writer at any time, Relational databases enforce ACID constraints that assume a single writer. Two concurrent writers to the same table can produce conflicting transactions, deadlocks, and corrupted indexes. Active-passive guarantees one writer by design.

A warm standby runs at 20% of primary capacity. The primary fails. What must happen before the warm standby can handle full production traffic?

The standby must scale up to 100% capacity, warm its caches, and pass health probes before receiving full traffic, A warm standby at 20% capacity cannot absorb 100% of production traffic without scaling up first. The scale-up takes 2 to 5 minutes, and cache warming adds another few minutes. Shifting full traffic to an un-warmed standby produces degraded latency for every user.

Active-Passive Failover

Name: System Design Masterclass
Availability: InStock

in Reliability Resilience

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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