Hemant Upadhyay - Get SDE Ready

Menu close menu icon System Design Interview Questions Adobe System Design Interview Questions Top Atlassian System Design Interview Questions Top Amazon System Design Interview Questions Top Microsoft System Design Interview Questions Top Meta (Facebook) System Design Interview Questions Top Netflix System Design Interview Questions Top Uber System Design Interview Questions Top Google System Design Interview Questions Top Apple System Design Interview Questions Top Airbnb System Design Interview Questions Top 10 System Design Interview Questions Mobile App System Design Interview Questions Top 20 Stripe System Design Interview Questions Top Shopify System Design Interview Questions Top 20 System Design Interview Questions Top Advanced System Design Questions Most-Frequented System Design Questions in Big Tech Interviews What Interviewers Look for in System Design Questions Critical System Design Questions to Crack Any Tech Interview Top 20 API Design Questions for System Design Interviews Top 10 Steps to Create a System Design Portfolio for Developers Introduction to High-Level System Design What is System Design? Difference Between HLD and LLD Key Considerations in HLD System Design Fundamentals Functional vs. Non-Functional Requirements Scalability, Availability, and Reliability Latency and Throughput Considerations Load Balancing Strategies Architectural Patterns Monolithic vs. Microservices Architecture Layered Architecture Event-Driven Architecture Serverless Architecture Model-View-Controller (MVC) Pattern CQRS (Command Query Responsibility Segregation) Scaling Strategies Vertical Scaling vs. Horizontal Scaling Sharding and Partitioning Data Replication and Consistency Models Load Balancing Strategies CDN and Edge Computing Database Design in HLD SQL vs. NoSQL Databases CAP Theorem and its Impact on System Design Database Indexing and Query Optimization Database Sharding and Partitioning Replication Strategies API Design and Communication REST vs. GraphQL vs. gRPC Designing Scalable APIs Rate Limiting and Throttling Authentication & Authorization (OAuth, JWT) Caching Strategies Types of Caching Cache Invalidation Strategies Redis vs. Memcached Cache-Aside, Write-Through, and Write-Behind Strategies Message Queues and Event-Driven Systems Kafka vs. RabbitMQ vs. SQS Pub-Sub vs. Point-to-Point Messaging Handling Asynchronous Workloads Eventual Consistency in Distributed Systems Security in System Design Encryption (AES, RSA, TLS) API Security Best Practices Secure Data Storage and Access Control DDoS Protection and Rate Limiting Observability and Monitoring Logging Strategies (ELK Stack, Prometheus, Grafana) API Security Best Practices Secure Data Storage and Access Control DDoS Protection and Rate Limiting Real-World System Design Case Studies Distributed locking (Locking and its Types) Memory leaks and Out of memory issues HLD of YouTube HLD of WhatsApp close menu icon Dropbox System Design: Scalable Cloud File Storage Architecture Introduction: What Is Dropbox Storage Architecture?Dropbox is a cloud file storage service that provides secure, reliable access to files from any device. Whether you’re on a laptop, smartphone, or public computer, your data is always within reach. But how do you design a scalable cloud storage system that supports millions of users and billions of files? If you’re new to distributed systems, begin with our cloud computing crash course to build foundational knowledge.Why Scalability and Performance MatterDesigning a file storage service at Dropbox scale isn’t just “save and retrieve.” You must balance:High throughput for uploads/downloadsGlobal availability across data centersData consistency vs. latency under the CAP theoremSecurity and end‑to‑end encryptionThis guide covers both functional requirements (core features) and non‑functional requirements (performance, reliability, security), walking through entity modeling, API design, chunked uploads, CDN integration, and real‑time file synchronization.Functional Requirements: Core Features Every Cloud Storage NeedsUpload from Any Device: Support laptops, mobile, tabletsDownload on Demand: Fast, presigned URLs for secure deliveryFile Sharing and Permissions: Grant view or edit accessAutomatic Sync: Instant mirroring across all devicesThese features must work on variable networks (fiber to spotty mobile) and for file sizes ranging from 2 KB to 50 GB.Non‑Functional Requirements: Ensuring Reliability and SecurityHigh AvailabilityLarge File Support (up to 50 GB)Performance (parallel chunk transfers, low latency)End‑to‑End EncryptionData Recovery for accidental deletesPrioritizing availability over strict consistency (AP in CAP) allows uploads in Berlin to appear in New York within seconds rather than blocking both.Core Entities and Metadata SchemaPrimary EntitiesFile: Raw byte contentFileMetadata: Name, size, MIME type, owner, timestampsUser: Account details and credentialsFileMetadata Schema { "id": "a1b2c3d4-e5f6-7890-g1h2-i3j4k5l6m7n8", "name": "company_retreat_video.mp4", "size": 5368709120, "mimeType": "video/mp4", "uploadedBy": "user123", "createdAt": "2025-03-04T09:12:45Z", "updatedAt": "2025-03-04T09:45:22Z", "status": "uploading", "fingerprint": "1a2b3c4d5e6f7g8h", "chunks": [ { "id": "chunk-0000", "size": 10485760, "status": "uploaded", "fingerprint": "aa1bb2cc3dd4" } // Additional chunks… ] } Learn best practices for metadata modeling in our Data Science curriculum.API Design: Building Blocks of Your ServiceUpload ProcessInitiate an UploadPOST /files { "name": "vacation_photos.zip", "size": 1572864000, "mimeType": "application/zip", "fingerprint": "5a8d7c9b6f3e2d1a", "chunks": 150 } Response: File ID and presigned URLs per chunk. Check Upload Status GET /files/{fileId}/status → { "status": "uploading", "completedChunks": 75, "totalChunks": 150 } Complete Upload POST /files/{fileId}/complete → { "status": "uploaded", "url": "/files/{fileId}" } Download Process Get Download URL GET /files/{fileId}/download { "url": "https://cdn.example.com/f8d7c9b6…?token=xyz789", "expiresAt": "2025-03-05T15:30:00Z" } Sharing APIsShare a FilePOST /files/{fileId}/share { "users": ["user456", "user789"], "accessLevel": "view" } Response: Success flag and sharedWith list.Sync APIsGet ChangesGET /files/changes?since={timestamp}WebSocket ConnectionGET /sync/connect for real‑time notifications. File Upload Process: Chunked and ResumableFingerprinting: Compute SHA‑256 on full file and on each chunk.Chunk Splitting: 5–10 MB pieces enable parallelism and resumability.Presigned Upload: Client uses S3‑style presigned URLs to upload chunks directly to blob storage.Compose: On completion, trigger server‑side assembly of chunks.Pro tip: Review our Master DSA, Web Dev & System Design program to deepen your understanding of fingerprinting algorithms and multipart upload patterns.File Download: CDN‑Optimized DeliveryPresigned URLs point to CDN endpointsEdge Caching reduces latency by serving files from nearest PoPByte‑Range Requests support resumable and streaming downloads Brush up on CDN integration strategies in our Web Development courses.File Sharing: Normalized Schema for EfficiencyUse a SharedFiles table rather than embedding share lists:UserIdFileIdSharedByTimestampAccessLeveluserAf8d7…1userA2025-02-28T15:30ZviewuserAf8d7…2userA2025-02-28T15:30ZeditThis enables fast queries like “What files have been shared with me?” without scanning all FileMetadata records.Real‑Time Sync: Local ↔ Remote ArchitectureLocal → RemoteFilesystem Events: inotify, FSEvents, FileSystemWatcherDelta Detection: Upload only changed chunks Remote → LocalWebSockets push change notificationsFallback Polling for reliabilityConflict Resolution: Last-write-wins and conflict‑copy creationFor deeper insights into distributed synchronization, explore our Essential DSA & Web Dev Courses for Programmers.Supporting Large Files: Overcoming Size LimitsTimeout Mitigation: At 10 Mbps, 50 GB ≈ 11 hours; chunking reduces this risk.Browser Constraints: Split into <4 GB requests to avoid HTTP limits.Resume Logic: Client asks server “Which chunks are missing?” by fingerprint query. Performance Optimizations: Maximizing ThroughputCDN Edge Servers: Global distribution for low-latency downloads.Parallel Transfers: 6–8 concurrent connections per domain.Adaptive Bandwidth: Dynamically adjust parallelism based on network conditions.File Compression: Apply to text and document formats when beneficial.Test your algorithmic skills with our Top Amazon DSA Interview Prep Guide and Top 20 DSA Interview Questions You Need to Know.System Architecture: Putting It All TogetherClients: Web, Mobile, Desktop SyncFrontend Services: Authentication, API Gateway, Web ServersBackend Services: File Service, Notification ServiceStorage: NoSQL Metadata, Blob Storage, Cache LayerInfrastructure: Load Balancers, Monitoring, Analytics, CDNConclusion: Building for Scalability and TrustworthinessA Dropbox‑like system blends chunking, metadata management, and real‑time sync into a seamless user experience. By favoring availability, leveraging CDNs, and implementing robust conflict resolution, you create a reliable, secure, and high‑performance cloud storage service. If you’re ready to advance your skills in system design and algorithms, check out our Top Meta Facebook DSA Interview Questions and dive into our complete DSA course lineup. This insightful blog post is authored by Hemanth Kumar, who brings his expertise and deep understanding of the topic to provide valuable perspectives. Hemanth kumar Java Developer | DSA, React, Spring Boot | ex-TA Coding Ninjas Got Confusion ? Accelerate your Path to a Product based Career Boost your career or get hired at top product-based companies by joining our expertly crafted courses. Gain practical skills and real-world knowledge to help you succeed. Explore our flagship courses Reach Out Now If you have any queries, please fill out this form. We will surely reach out to you. Contact Email Reach us at the following email address. arun@getsdeready.com Phone Number You can reach us by phone as well. +91-97737 28034 Our Location Rohini, Sector-3, Delhi-110085

Author: Hemant Upadhyay

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