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 is watermark alignment so important in a stream to stream join?

The effective watermark is the minimum across inputs, so a slow side holds back the whole join and state on the fast side piles up until alignment catches up, Flink tracks a watermark per input and uses the minimum. A slow side blocks all windows from closing, which means the fast side's state keeps growing. Without explicit alignment, the fast side can OOM while waiting. Flink's alignWatermarks option enforces coordinated progress.

A Flink job runs a 30 minute interval join on an ad network processing 100K events per second per side. What is the primary resource concern?

State size in RocksDB, since both sides must buffer every event for the full window length (roughly 180 million events), Both sides of an interval join buffer every event for the window length so late records can still match. At 100K per side over 30 minutes that is 180 million events in RocksDB. State size drives disk, memory, and checkpoint cost. Window length and state size are the same decision.

What is the correct way to handle events that arrive after a stream join window has closed?

Route them to a side output with allowed lateness, log counts, and optionally feed them into a correction pipeline, Dropping silently causes slow drift that nobody notices until an audit. Flink's side output mechanism routes late records to a separate stream where they can be counted, logged, and optionally fed into a correction pipeline. This gives you an SLO to monitor and a knob to tune.

Stream-to-Stream Joins

Name: System Design Masterclass
Availability: InStock

in Stream Batch Processing

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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India

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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

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