38. Pre-Signed Direct Upload
Streaming multi-gigabyte uploads through application servers wastes the most expensive capacity in the system on copying bytes, and ties up a request for minutes on a connection that may drop.
Product & backendMedium
Guided practice
Start with a template. Work through each step. Ask Coach when you need a second opinion.
Designs with worked examples 5
Ordered by design numberCompany tags are community-reported. Counts on cards show how many people reported that design.
Amazon S3Clear filters
46. Design a Web Crawler
Ten billion pages in five days, politely, without losing progress: fetchers and parsers, domain locks, bandwidth math, deduplication and a crawl that stays fresh. One-hour boards for junior, senior and staff.
ClassicMedium54. Design a Photo Sharing App like Instagram
Photos and videos for 500 million daily users: presigned multipart uploads, a processing pipeline, CloudFront and a hybrid fan-out feed.
ClassicMedium68. Design Large File Uploads and Downloads
Files up to 50 GB up and down without a byte through the API: presigned URLs, resumable multipart, S3 events, scanning and CloudFront.
ClassicMedium79. Design Object Storage like Amazon S3
An S3-inspired object store: bytes before metadata, a partitioned namespace with cache coherence, then repair, heat, lifecycle and safe change. Three interview boards with explicit assumptions and AWS source boundaries.
ClassicMedium