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FAANG Interview Prep

Crack the System Design & Java Interview.

Deep-dive notes from a Senior Engineer at Salesforce (ex-Walmart, Siemens). Not generic theory — real patterns, tradeoffs, and code used in production at scale.

by Vamsi Karuturi · Senior Backend Engineer at Salesforce

300+ In-Depth Articles
1,600+ Interview Questions
95 Java Deep Dive Topics
Start Learning Path → Interview Questions

NEW in 2026 Latest: Go Deep Dive (production patterns, concurrency) · AI Agents & Tool Use · URL Shortener (with interviewer pushback scenarios) · Java 23-25 coverage · DevOps (secrets management, incident response, multi-env promotion)

How Much Time Do You Have?

Sprint Mode — 2 Weeks

Interview next week? Focus on the 20% that covers 80% of questions.

Collections → Concurrency → @Transactional → System Design Guide → Behavioral

FAANG Interview Prep — 4-6 Weeks

Assumes Java proficiency. Focused on what FAANG actually asks.

OOP → Collections → Spring Boot → Microservices → Design Patterns

Deep Prep — 6 Months (Fresher / Career Switch)

Starting from CS basics? This path builds from zero to FAANG-ready with no gaps.

Java Basics → OOP → DSA → Collections → Threading → Patterns → Spring Boot → SQL → System Design → Microservices → Behavioral
Specialized Tracks

Spring Boot Mastery

Zero to production-ready. IoC, JPA, Security, Testing, Actuator.

IoC & DI → JPA → Transactions → Security → Testing

Microservices Architect

Design, build, deploy, and observe distributed systems. Prereq: Spring Boot basics.

Design → Comm. → Resilience → Deploy → Observe

System Design — Case Studies

11 real system designs with architecture diagrams. Prereq: Distributed systems fundamentals.

URL Shortener → Rate Limiter → Chat System → Notifications → Payments
Core Engineering

Java Deep DiveJVM, Collections, Concurrency, Streams, Java 17+

Spring Boot 23 TopicsIoC, AOP, JPA, Security, WebFlux, Testing, Actuator

Microservices 25 TopicsSaga, CQRS, gRPC, Service Mesh, Resilience, Observability

Design PatternsAll 23 GoF — Creational, Structural, Behavioral

LLD Roadmap HOTComplete roadmap, resources, 35+ interview Qs

SOLID PrinciplesSRP, OCP, LSP, ISP, DIP with real examples

Featured Deep Dives

Spring Boot @Transactional Deep Dive Propagation, isolation, self-invocation trap, readOnly optimization — everything for your interview.

Microservices Resilience Patterns Retry, Circuit Breaker, Bulkhead, Rate Limiter — with Resilience4j code and Istio comparison.

Spring Boot AOP & Custom Annotations Build @LogExecutionTime, @RateLimit — understand proxy-based weaving and its pitfalls.

Microservices Distributed Transactions Saga choreography vs orchestration, Outbox Pattern, idempotency — with full code.

System Design

System Design FundamentalsHTTPS, CAP Theorem, Rate Limiting, Caching

API DesignREST best practices, pagination, HATEOAS

Load BalancingAlgorithms, L4 vs L7, health checks

RedisCaching, pub/sub, data structures

Distributed CachingStrategies, consistency, eviction policies

SQL vs NoSQLWhen to pick what and trade-offs

Networks & Operating Systems

Computer Networks NEWTCP/IP, DNS, HTTP/3, TLS, routing, packet analysis

Network SecurityDPI, C2 detection, Zero Trust, threat telemetry

OS Fundamentals NEWProcesses, memory, scheduling, syscalls, Windows/Linux internals

OS Security & EDRProcess injection, ransomware detection, MITRE ATT&CK, Defender internals

Data & Messaging

SQLQueries, joins, indexes, optimization

PostgreSQLReplication, sharding, tuning

KafkaTopics, partitions, consumer groups, exactly-once

GraphQLQueries, mutations, subscriptions, SDL

DevOps & Cloud

DockerContainers, Compose, multi-stage builds

KubernetesPods, services, deployments, Helm

AWSEC2, S3, Lambda, ECS, CloudFormation

CI/CD PipelinesJenkins, GitHub Actions, deploy strategies

LinuxCommands, shell scripting, permissions

AnsiblePlaybooks, roles, automation

Languages

GoGoroutines, channels, interfaces

PythonFundamentals, data structures, scripting

TypeScriptTypes, generics, decorators

RustOwnership, borrowing, zero-cost abstractions

KotlinNull safety, coroutines, JVM

RubyDynamic typing, Rails, metaprogramming

More

AI & MLLLMs, RAG, transformers, MLOps

SecurityOAuth 2.0, JWT, auth patterns

TestingJUnit 5, TDD, mocking, integration

Behavioral — Amazon LPs HOT14 Leadership Principles with STAR answers

Interview PrepCommon questions & answers by topic

Clean ArchitectureLayers, boundaries, dependency rule

Topics covered for interviews at
Google Amazon Meta Microsoft Apple Netflix Uber Stripe Salesforce Walmart