Migration · Fintech · 6 months
Fintech Core Replatforming
A payments company ran its ledger on aging colocated hardware with backups it had never tested. We designed a multi-AZ AWS architecture, replicated data with dual-write verification for three weeks, and cut over on a Sunday morning with a one-command rollback nobody needed.
-
Prove the foundation first
Multi-account landing zone, customer-managed keys and append-only logging went in before a single workload moved — so every later decision inherited guardrails instead of negotiating them.
-
Dual-write until the data agrees
Three weeks of parallel writes with an automated differ caught eleven discrepancies before cutover — eleven incidents that never happened.
-
Cut over calmly, roll back instantly
A 47-step runbook with a one-command rollback, rehearsed four times in staging. Cutover took 34 minutes against a four-hour window.
- AWS
- Terraform
- Aurora
- MSK
Running a ledger on hardware you don't trust?
Send me your architecture diagram — I'll tell you what the migration really costs.
Start a project