238 Animated Explainers · 7 Tracks

Concept Explainers

Watch the flows interviewers ask about come to life. 238 animated, step-through walkthroughs — HTTPS, Kubernetes, load balancing, RAG, CAP theorem, two-pointers — with auto-play, voice narration, an interactive "what if…?" remix, and on-demand custom generation.

What Happens When You Enter a URL

Web & CS Basics · beginner

1 / 6

Client

Network

Server

🧑‍💻Browser

🎨Render

🌐DNS Resolver

⚖️Load Balancer

🖥️Web Server

🗄️Database

Step 1 of 6

DNS Resolution

The browser asks a recursive DNS resolver to turn the hostname into an IP address, then caches the answer.

💡 Interview angle: Mention TTL and caching — a warm DNS cache skips this round-trip entirely.

Step 2 of 6

TCP + TLS Handshake

A TCP three-way handshake opens the connection, then TLS negotiates keys so the channel is encrypted.

💡 Interview angle: TLS 1.3 completes the handshake in a single round-trip (1-RTT); 1.2 took two.

Step 3 of 6

HTTP Request

The browser sends an encrypted GET request; the CDN / load balancer routes it to a healthy origin server.

💡 Interview angle: Headers and cookies ride here — Host, Accept-Encoding, and any session cookie.

Step 4 of 6

Server Processing

The app server runs business logic and queries the database, then assembles the HTML response.

💡 Interview angle: A cache hit avoids the DB entirely — this is where TTFB is usually won or lost.

Step 5 of 6

Response

The server streams a 200 OK with the HTML body back over the encrypted connection to the browser.

💡 Interview angle: gzip / Brotli compression shrinks the body so the first bytes arrive sooner.

Step 6 of 6

Browser Render

The browser parses HTML into the DOM, applies CSS, then lays out, paints, and composites the pixels.

💡 Interview angle: This is the critical rendering path — render-blocking CSS/JS delays first paint.

‹▶ Auto-play›↻ Replay🔊 Voice

0.5×1×2×3×

In the library

238 flows

Seven Tracks, 238 Flows

From the request that loads a web page to the pipeline behind a RAG system — the whole technical-interview surface, animated.

106

Software & System Design

Load BalancingCachingShardingRate Limiting

AI / ML

RAG PipelineTransformer AttentionEmbeddingsAgent Tool-Use

DevOps

Kubernetes IngressCI/CDBlue-GreenCanary Deploys

DSA & Coding Patterns

Two PointersSliding WindowBFS vs DFSBacktracking

Cloud

VPC TrafficServerlessS3 Request PathIAM Eval

Networking

DNS ResolutionTCP HandshakeHTTP/3Congestion Control

Web & CS Basics

URL → RenderCORS & PreflightCookies & SessionsXSS / CSRF

Step-Through Mode

Move One Step at a Time — Until It Clicks

Take the HTTPS / TLS 1.3 handshake. Auto-play it once to see the shape, then step through each exchange yourself. The diagram highlights the active stage and the narration explains exactly what's happening — so you can explain it back in the room.

Manual step Auto-play Voice

HTTPS / TLS 1.3 HANDSHAKE — 4 STEPS

ClientHello

Client sends supported cipher suites + a random value

ServerHello

Server picks a cipher, returns its certificate

Key Exchange

Both sides derive the shared session key

● active

Finished

Encrypted application data starts flowing

Not Just Watch — Interrogate the Flow

Real understanding comes from asking "what changes if…". So you can — and the diagram answers.

"What if…?" Remix

Pose a hypothetical and the explainer re-renders to show the consequence — stack changes on top of each other to explore a whole design space.

What if we add a Redis cache between the service and the database?

What if this component goes down?

What if we double the traffic?

Generate On-Demand

The library has 238 flows — but if yours isn't there yet, describe it and get a fresh animated, step-through explainer built on the spot.

> Explain how a distributed lock works with Redis Redlock

Learn It the Way It Actually Works

Motion makes systems memorable. Here's everything packed into each explainer.

Auto-Play or Step Through

Watch the whole flow animate end-to-end on auto-play, or drive it yourself one step at a time. Every stage pauses on the exact node so you can sit with it until it clicks.

Voice Narration

Turn on narration and each step is explained out loud as the packets travel — perfect for learning a system design flow on a commute or while you sketch along.

"What if…?" Interactive Remix

Ask a hypothetical and watch the diagram change. "What if we add a Redis cache?" "What if this node goes down?" "What if we double the traffic?" — the flow re-renders to show the answer.

Generate Any Concept On-Demand

Need something that isn't in the 238-explainer library yet? Describe it and a brand-new animated, step-through explainer is generated for you — tuned to the exact flow you're studying.

Real Diagrams, Not Slides

Every explainer is a live node-and-edge diagram with packets moving across it — so you see how requests, data, and control actually flow, the way an interviewer wants you to draw it.

Built for the Whiteboard Round

These are the exact flows interviewers ask you to explain — HTTPS, Kubernetes, load balancing, RAG, CAP theorem, two-pointers. Learn them as motion, then reproduce them under pressure.

Stop Memorising. Start Seeing.

You can read about load balancing a dozen times and still freeze when asked to draw it. Watching the packets move — then stepping through it, then remixing it — is what makes it stick.

238 animated, step-through explainers across 7 interview-critical tracks

See how requests and data actually flow — not static slides or walls of text

Auto-play, manual step, and voice narration for whichever way you learn best

Ask "what if…?" and watch the diagram re-render to answer your hypothetical

Generate a custom explainer for any concept that isn't in the library yet

The exact flows interviewers ask you to explain on the whiteboard

238

Animated explainers across system design, DevOps, cloud, AI/ML, networking, web fundamentals, and coding patterns

7 tracks

Organised by the way interviews are actually structured — search and filter to exactly what you're prepping

On-demand

Generate a brand-new explainer for anything not yet in the library

See the Flow Before You Have to Draw It

238 animated, step-through explainers of the exact concepts interviewers ask about — auto-play, voice, "what if…?", and custom generation.