diff --git a/docs/ARCHITECTURE.md b/docs/ARCHITECTURE.md
index a018249..edd68ff 100644
--- a/docs/ARCHITECTURE.md
+++ b/docs/ARCHITECTURE.md
@@ -97,14 +97,14 @@ SkyView is a high-performance, multi-source ADS-B aircraft tracking system built
 **Purpose**: Provides comprehensive ICAO address to country mapping
 
 **Key Features**:
-- Embedded SQLite database with 70+ allocations covering 40+ countries
-- Based on official ICAO Document 8585
-- Fast range-based lookups using database indexing
-- Country names, ISO codes, and flag emojis
+- In-memory database with 100+ allocations covering 70+ countries and territories
+- Based on official aerotransport.org ICAO allocation tables
+- Fast binary search lookups on sorted allocation ranges
+- Complete country names, ISO codes, and flag emojis
+- Zero external dependencies - pure Go implementation
 
 **Files**:
-- `database.go`: SQLite database interface
-- `icao.db`: Embedded SQLite database with ICAO allocations
+- `database.go`: In-memory ICAO allocation database with binary search
 
 ### 5. HTTP/WebSocket Server (`internal/server/`)
 
@@ -157,7 +157,7 @@ SkyView is a high-performance, multi-source ADS-B aircraft tracking system built
 
 ### 3. Country Lookup
 1. **ICAO Extraction**: Extract 24-bit ICAO address from aircraft data
-2. **Database Query**: Lookup country information in embedded SQLite database
+2. **Database Query**: Lookup country information in in-memory database using binary search
 3. **Data Enrichment**: Add country, country code, and flag to aircraft state
 
 ### 4. Data Distribution
@@ -256,7 +256,6 @@ SkyView is a high-performance, multi-source ADS-B aircraft tracking system built
 - **Leaflet.js**: https://leafletjs.com/ - Interactive maps
 - **Three.js**: https://threejs.org/ - 3D visualization
 - **Chart.js**: https://www.chartjs.org/ - Statistics charts
-- **SQLite**: https://www.sqlite.org/ - ICAO country database
 - **WebSocket Protocol**: RFC 6455
 
 ### ADS-B Ecosystem