Hands On System Design - Distributed Systems Implementation

Hands On System Design - Distributed Systems Implementation

Hands On Production-grade distributed log platform — Build LogStream (Java/Spring boot)

Day 57: Full-Text Search with Relevance Scoring

May 08, 2026
∙ Paid

What We’re Building Today

  • Elasticsearch integration for distributed full-text search across log streams

  • BM25 ranking algorithm implementation with custom scoring functions

  • Multi-field search supporting structured and unstructured log data

  • Real-time search API with sub-100ms query latency for millions of logs

Why This Matters

When Netflix processes 500 billion events daily, engineers need to find specific error patterns across distributed services in seconds, not hours. Traditional database queries fall apart at this scale—a LIKE '%error%' query on 100M log entries will bring PostgreSQL to its knees. Full-text search engines like Elasticsearch solve this by inverting the problem: instead of scanning documents for terms, they build inverted indices that map terms to documents instantly.

The challenge isn’t just speed—it’s relevance. When searching “authentication timeout user service,” you want logs matching all terms ranked higher than partial matches, recent errors prioritized over old ones, and critical severity logs surfaced first. This requires sophisticated scoring algorithms that understand both textual similarity and domain-specific importance signals.

System Design Deep Dive

User's avatar

Continue reading this post for free, courtesy of System Design Course.

Or purchase a paid subscription.
© 2026 Systemdr, Inc. · Privacy ∙ Terms ∙ Collection notice
Start your SubstackGet the app
Substack is the home for great culture