Christopher Lim

About

Backend/data engineer focused on compliance and statistical processing systems on AWS, building containerized FastAPI services plus event-driven async workflows (Step Functions/EventBridge) with strong reliability patterns (JWT auth, idempotency, structured logging). Has modernized SAS-based batch pipelines into modular Python/AWS services with parallel-run parity validation, and has demonstrated measurable SQL performance wins (40+ min to <10 min) and hands-on incident ownership using CloudWatch-driven detection and prevention.

Experience

Education

Key Strengths

• Designed and owned event-driven Python backend (FastAPI + ECS + Step Functions) with S3/RDS persistence
• Strong reliability engineering: JWT auth, explicit timeouts, safe retries with exponential backoff, standardized 4xx/5xx handling, idempotent async workflows
• Production AWS delivery with IaC (CloudFormation/Terraform) and CI/CD (ECR builds, automated rollbacks, multi-environment promotion)
• Data engineering with AWS Glue: schema evolution handling, data quality gates, rejected-record capture, idempotent reruns
• Legacy SAS batch modernization to modular Python/AWS services with parallel-run parity validation and phased cutover
• SQL optimization with measured impact (reduced reconciliation job runtime from 40+ minutes to <10 minutes via indexing, temp tables, partitioning)
• Owned production ETL incident response: detected via CloudWatch alarms, mitigated by isolating bad batches and adding validation guards; added preventative controls (retry caps, anomaly alerts)