Advanced · 3 weeks
File Storage Service (S3 Abstraction)
Upload/download files with metadata in DB and blobs in S3. Pre-signed URLs, multipart upload, virus scan hook, and access control per file owner.
Why this project
File handling is common in backend work. Pre-signed URLs and multipart upload are frequent interview topics.
Tech stack
Java 17Spring Boot 3AWS S3 SDKPostgreSQLSpring Security
Skills demonstrated
- Object storage integration
- Pre-signed URLs
- Multipart upload
- Metadata management
Interview talking points
- Why pre-signed URLs
- Multipart upload flow
- Consistency between S3 and DB on failure
- CDN integration for public files
Problem statement
Upload/download files with metadata in DB and blobs in S3. Pre-signed URLs, multipart upload, virus scan hook, and access control per file owner.