Moving a regulated financial platform to AWS
Before go-live I found 11 blockers in the vendor’s code, fixed infrastructure code that had never compiled, and on the night of 14 October 2026 ran the brokerage platform’s cutover to production on AWS.
- Blockers found before go-live
- 11
- Resources in Pulumi
- 59
- Data migration, 100% validated
- 43 min
- RPO / point-in-time window
- ~5 min / 35 days
Full stretch
- Starting point
- The original app on shared hosting. A vendor was building a new system for two brands in parallel, meant to replace half of the application. A regulated sector, so backups and audit are not optional. Infrastructure, deployment and the cutover were mine; the code was the vendor’s.
- Constraints
- The old app has to keep running until the new system is ready. The vendor’s infrastructure code had never compiled. The cutover had one night.
- Decision
- The load balancer routes requests by domain and path, part to the old app and part to the new system. Three environments as separate Pulumi stacks, deployed through GitHub Actions with OIDC.
- Result
- Production has run on AWS since 14 Oct 2026. I checked the vendor’s claims against the actual code; the blockers ranged from missing authorization to personal data in logs. Rolling deploys with automatic rollback, documented RPO and RTO, and a gap analysis against DORA.
- What I would do differently today
- I would spend more time on preparation and thinking it through, and less on fixes.