Lessons on Reconciliation at Scale With Serverless Architecture

Reconciliation at scale is the difference between trusting your financial records and spending nights chasing mismatches across multiple parties. At Lead Bank, we build the infrastructure that collects, processes, and reconciles data for card and deposit programs. This post walks through the AWS serverless architecture we built for multi-party reconciliation, the two production bottlenecks we encountered first (file processing limits and Amazon DynamoDB write hot spots), and the patterns we used to mitigate them.