Refactored REST microservices in Java (Spring Boot) to cut P95 latency by 47% (320ms → 170ms), optimized PostgreSQL queries, and added Redis caching for asset/fault data (50K+ req/day). Built Airflow ETL ingesting 10M+ records/day with schema validation; dropped corrupt rows by ~70% and stabilized downstream analytics. Containerized with Docker and shipped via GitHub Actions → AWS (EC2, RDS, S3, CloudWatch); raised deploy frequency from 1/month to 3/week, kept change failure rate <5% and service 99.95% uptime. Added tests and observability (JUnit, pytest, Prometheus, Grafana, ELK), cutting on-call triage time ~35% and lifting coverage to ~75%. Partnered with analysts to reshape tables and composite indexes; enabled 8+ KPI dashboards in Grafana/Kibana.

Software/Security Engineering Intern at Hangzhou DPtech Co., Ltd.

August 1, 2024 - August 1, 2024

Shipped Kafka + Fluentd/Logstash → Elasticsearch/ClickHouse pipeline for NetFlow/Syslog from 120+ devices (1.2B+ events/mo); Kibana triage cut alert handling time ~40%. Built rule dedup & prioritization for firewall/IDS; pruned ~32% redundant ACL/IPS rules and lifted throughput ~22% in load tests. Prototyped anomaly detection (rolling z-score, IsolationForest) on traffic features; flagged 230+ high-risk events with false positives reduced by 27% in pilot. Integrated OpenVAS with Jira REST for auto-ticketing; reduced MTTR from 14 days to 9 days (−36%) and improved SLA. Authored hardening playbooks (TLS/mTLS, RBAC, log retention) and exposed audit APIs adopted by 4 internal tools.