All case studies
  • Fintech
  • Cloud & DevOps
  • Data pipelines

Core banking moved to hybrid cloud without a minute of downtime.

We moved a Lagos payments company’s core ledger from an overloaded on‑premise cluster to a hybrid cloud, one domain at a time, while customers kept transacting.

Client
Payments company, Lagos
Services
Cloud & DevOps, data pipelines, QA
Timeline
12 weeks · 6 engineers
Stack
AWS · Kubernetes · PostgreSQL · Go
A long data-centre aisle lined with server racks

Results

The numbers after go‑live.

Measured over the first six months in production.

Customer‑facing downtime
0 min
Accounts migrated
14M
Infrastructure cost
−38%
Uptime since launch
99.99%

01

The challenge

A ledger that couldn’t go down, on servers that couldn’t keep up.

Every payment the business processed touched one on‑premise ledger. Growth had pushed it past capacity: nightly batch reconciliation was spilling into business hours, and every release needed a four‑hour maintenance window.

The brief was blunt. Move to the cloud, keep the regulator comfortable, and do it without customers noticing.

02

The approach

Migrate in slices. Rehearse until it’s boring.

We ran the old and new ledgers side by side, moved one domain at a time, and only cut over when the numbers matched to the kobo.

  1. AShadow ledgerThe new ledger ran in parallel for six weeks, reconciling every transaction against the old one each night.
  2. BStrangler migrationPayments, accounts and reporting moved behind an API gateway one domain at a time.
  3. CRehearsed cutoverThree full dress rehearsals on production‑sized data before the live weekend.
  4. DObservability firstDashboards, alerts and runbooks were live before the first customer moved.

Before · on‑premise

  • Single on‑premise cluster
  • Nightly batch reconciliation
  • 4‑hour maintenance windows
  • Manual releases, once a month

After · hybrid cloud

  • Active‑active across two regions
  • Real‑time reconciliation
  • Zero‑downtime releases
  • 40+ automated deploys a week

03

The outcome

Customers noticed nothing. The finance team noticed everything.

Cutover finished early on a Sunday morning with zero failed transactions. Reconciliation that used to take a night now runs continuously, and the team ships several times a day instead of once a month.

Client voice

“Bettalabs rebuilt our ledger in twelve weeks and we haven’t had a reconciliation incident since. They work like our own senior team, not a vendor.”

Adaeze N.Chief Technology Officer · Payments company, Lagos
from kickoff to production
12 wks
faster month‑end reconciliation
3×

Let’s build

Got something impossible in mind?

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or write to hello@bettalabs.org