The professional graph is the core: connections live in a graph store that answers 'how am I connected to this person?' and powers 'People you may know'. Posts fan out to connections' feeds and are ranked by a model. Jobs are a separate search vertical matched to profiles, and messaging runs on a real-time tier.
Functional requirements
- Profiles with experience, skills and education
- Send and accept connection requests; follow people and companies
- Post updates; see a ranked feed
- Search people and jobs; apply to jobs
- Direct messaging and notifications
Non-functional requirements
- Graph queries (degree of connection) in milliseconds
- Feed loads quickly for hundreds of millions of users
- Profile updates visible in search within minutes
Extensions
- Company pages and recruiter tools.
- Learning courses.
- Skill assessments and endorsements.