Refactor with discipline: identify bounded contexts, extract services incrementally, stabilize APIs, migrate data safely, and add observability before retiring monolith code.

Cut serverless costs by right-sizing memory, capping concurrency, caching hot paths, and offloading steady workloads where provisioned capacity beats per-request pricing.

Minimize downtime by rehearsing upgrades on replicas, validating extensions, using logical replication or pg_upgrade, and scheduling a brief, tested cutover window.

Resolve Rails dependency conflicts by auditing Gemfile.lock, upgrading gems in small batches, checking changelogs, and pinning versions only when tests confirm compatibility.

Secure migration to AWS starts with data classification, encrypted transfer, IAM least privilege, and validation checks to preserve integrity while modernizing legacy on-premise systems.