# 📚 Senior Full Stack Interview Bible

> **A lane-first, stack-deep reference for senior full-stack engineers (5+ YoE)** prepping for product-based companies, FAANG/Big Tech, and EU mid-stage startups. Pick your lane, drill the stacks.

[![Lanes](https://img.shields.io/badge/lanes-3-blue)](lanes/INDEX.md)
[![Stacks](https://img.shields.io/badge/stacks-7-green)](INDEX.md)
[![Files](https://img.shields.io/badge/files-400%2B-orange)](INDEX.md)
[![Last Updated](https://img.shields.io/badge/last%20updated-August%202026-purple)](#)

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## 🛣️ Pick Your Lane

The bible is split into **3 lanes**. The stacks are the technical material they share; the lanes are the strategy, prep plan, and behavioral overlay for a specific job-market.

| Lane | Folder | Audience | Bar | Time |
|------|--------|----------|-----|------|
| **Cross-Lane** — universal interview strategy | [strategy/](strategy/INDEX.md) | Everyone starts here | Resume, STAR, communication | Read in 1-2 days |
| **Indian SDE / FAANG** | [indian-sde-faang/](lanes/indian-sde-faang/INDEX.md) | Microsoft, Google, Amazon, Meta, Apple, in-country India | LeetCode medium-to-hard, 5-6 rounds | 8-12 weeks @ 4-6 hrs/day |
| **Abroad Full-Stack** | [abroad-full-stack/](lanes/abroad-full-stack/INDEX.md) | EU mid-stage startups (n8n, SumUp, Scalable, sennder, THRYVE, Peter Park) + remote-first US | Take-home + system design, 3-4 rounds | 4-6 weeks @ 2-3 hrs/day |

**Quick heuristic:** If the phone screen has a LeetCode medium-to-hard → Indian SDE / FAANG. If the company is mid-stage and uses take-homes → Abroad Full-Stack. Many EU Big Tech (Booking, Spotify) run FAANG-style loops → use both.

👉 Full decision matrix: [abroad-full-stack/INDEX.md → Lane Decision](lanes/abroad-full-stack/INDEX.md#lane-decision--is-this-the-right-lane-for-you)

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## 📚 The 7 Study Stacks

Both lanes pull from the **same 7 study stacks**. Pick a topic, drill the stack. Lanes never reference each other — only the stacks.

| Stack | Folder | What's in it | Files |
|-------|--------|--------------|------:|
| **Frontend** | [frontend/](frontend/INDEX.md) | JavaScript, TypeScript, React, Next.js, Forms, Animation | 90 |
| **Backend** | [backend/](backend/INDEX.md) | Node.js, NestJS, REST, GraphQL, Database, Security, Patterns, Microservices | 107 |
| **Architecture** | [architecture/](architecture/INDEX.md) | System design, CAP, consistency, sharding, queues, 30+ case studies | 36 |
| **Platform** | [platform/](platform/INDEX.md) | Docker, K8s, CI/CD, Observability, Build Tools, Git, Serverless, Monorepo | 63 |
| **Quality** | [quality/](quality/INDEX.md) | Testing (Jest/RTL/Playwright), Accessibility, Performance | 26 |
| **Real-Time** | [realtime/](realtime/INDEX.md) | WebSockets, SSE, real-time architecture | 8 |
| **Interview Toolkit** | [interview-toolkit/](interview-toolkit/INDEX.md) | Behavioral, Coding Patterns, Cheat Sheets | 27 |

👉 Full breakdown with file counts per topic: [INDEX.md → The 7 Study Stacks](INDEX.md#-the-7-study-stacks-shared-by-both-lanes)

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## 🗺️ Navigation

| If you want to… | Go to |
|------------------|-------|
| See all files in one place | [INDEX.md](INDEX.md) |
| Start with universal interview prep | [strategy/](strategy/INDEX.md) |
| Prep for FAANG / Indian SDE roles | [lanes/indian-sde-faang/](lanes/indian-sde-faang/INDEX.md) |
| Prep for EU mid-stage / remote-first US | [lanes/abroad-full-stack/](lanes/abroad-full-stack/INDEX.md) |
| Learn how to contribute | [contributing.md](contributing.md) |

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## 📝 Chapter Template

Every chapter follows a consistent structure:

```text
# Topic

## Definition

## Why Do We Need It?

## How It Works (with diagrams)

## Code Examples (TypeScript)

## Real-World Use Cases

## Common Mistakes

## Best Practices

## Performance Considerations

## Interview Questions
  ### Beginner (10)
  ### Intermediate (10)
  ### Senior (20)
  ### FAANG-style (10)
  ### Follow-ups (10)

## Summary

## References & Learn More
```

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## 💡 How to Use

| Goal | Approach |
|------|----------|
| **New to a topic** | Start with the definition and "Why" sections |
| **Preparing for an interview** | Follow your lane's 4-week or 8-week prep plan; the lane tells you which stack files to read in what order |
| **Quick review** | Use the Cheat Sheet at the bottom of each chapter, or the [interview-toolkit/cheatsheets/](interview-toolkit/cheatsheets/INDEX.md) stack |
| **Deep dive** | Read through internal working and code examples |
| **Cross-reference** | Each stack folder has an `INDEX.md` listing all files with file counts |

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## 🏆 Quick Lane Summary

### 🇮🇳 Indian SDE / FAANG (23 files in lane)

DSA-heavy. The bar is **1-2 mediums in 30-45 min, plus 1 system design, plus 1-2 behavioral, plus a Bar Raiser (Amazon) or values round**. 5-6 rounds, 8-12 weeks. US FAANG comp: USD 260-580K (E4-E5). Indian in-country: INR 30-120 L (SDE-2 to SDE-3).

→ [Indian SDE / FAANG lane →](lanes/indian-sde-faang/INDEX.md)

### 🇪🇺 Abroad Full-Stack (14 files in lane)

Take-home heavy. The bar is **a 5-6 hour take-home, 1-2 mediums in 30 min, 1 system design at 45 min, 1 behavioral round**. 3-4 rounds, 4-6 weeks. EU Tier 1 comp: EUR 75-110K base + 0.05-0.5% equity. Family-driven geography (NL 30% ruling, EU Blue Card, schools).

→ [Abroad Full-Stack lane →](lanes/abroad-full-stack/INDEX.md)

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*Last updated: August 2026 — 3 lanes, 7 stacks, 400+ files, 0 broken links*