Matthew Mullins

About

Backend/data platform engineer with production experience at Walmart and Molina Healthcare, building Python microservices on AWS (EKS + Lambda) for real-time inventory and recommendation systems. Strong in reliability/observability and incident leadership, plus modernizing legacy healthcare workflows and building resilient AWS Glue/PySpark pipelines with schema evolution and data quality controls.

Experience

Education

Key Strengths

• Designed and maintained large-scale Python backend APIs for real-time inventory lookup and personalized recommendations
• Reliability engineering: stateless APIs, JWT auth, consistent structured errors, explicit timeouts/retries/backoff, graceful degradation
• Scaling under peak events: circuit breaking, Redis caching, async workflows, and Kubernetes autoscaling tuned to app metrics (latency/queue depth)
• Strong observability practice (Prometheus metrics, Datadog tracing, structured logging) with dashboards and alerting
• Production leadership: served as incident commander, led RCA, and improved recovery times
• ETL resilience on AWS Glue/PySpark: schema evolution handling, data quality checks, quarantine paths, and partition-level replays
• Legacy modernization with risk control: reverse-engineered business rules, rebuilt as Python services, parallel runs with granular parity checks, phased rollout/rollback
• SQL optimization with measured impact (20–25% query execution time reduction) using execution plans and indexing/join restructuring
• Operational incident response for batch pipelines: detected via freshness/SLA alerts, mitigated via re-partitioned reruns, and added trend-based early warning monitoring