San Cao
Backend Engineer • Infrastructure

Backend Infrastructure.
Reliability, Migration & Observability.

Managing 1,000+ DB Clusters at Zalo with zero-downtime migration. Developed backup agents for 18TB+ daily data. Ingesting ~1M samples/sec for sub-second observability.

0x01 / Data Integrity & Reliability

18TB Daily Data Protection

Engineered a high-performance backup agent with reproducible build pipelines. Implemented weekly production consistency checks and automated restore testing to ensure 100% recoverability for Zalo's massive data footprint.
18TB/Day Hermetic Build Consistency Check Auto-Restore Zero Copy
0x02 / Metrics Ingestion
~1M/s
Thanos long-term store architecture, cutting storage costs by 3.5x.
0x03 / Cluster Scale
1,000+
DB clusters maintained with cross-DC automated replication.
0x04 / Migration & Traffic Routing

Zero-Downtime Migration

Architected migration protocols and automated cross-DC replication for 1,000+ DB clusters. Ensured transparent transitions for users with no perceived service interruption.

Warm-StandbyCross-DCZero-Downtime
0x05 / Backend & Security
Implemented in-memory encryption for Memcached, securing PII for 70M+ users with <2% latency impact.
Stack
C/C++
Impact
70M+ MAU Security
MemcachedAES-NIPII SecurityC/C++NUMA
0x07 / Featured Projects
Uptime: 99.99%
MY RESUMÉ