Nexus Bank: Core Banking Migration

Third-party integrations (CBM.2.6.1 to CBM.2.6.10, no owner) are 8% complete. The source comment says 211 of 340 critical integrations are assigned, 129 have no developer because A. Park resigned, and the current team of three engineers would finish in Jan 2027. The iOS lead (T. Ferreira) and L. Obi also resigned, and knowledge transfer is only partly done.

The integration build quality gate is dated 23 Dec 2026, 80 working days after its baseline, and it has -80 days of float. SIT, UAT, the parallel run and go-live follow it, so go-live is dated 8 Jul 2027, 80 working days after baseline. Two replacement engineers are onboarding and need 6 to 8 weeks to become productive (source comment).

The notification is a milestone dated 1 Sep 2026 (CBM.5.1.5). Preparing it (CBM.5.1.4, M. Andersen) starts 1 Jul 2026 and is 0% complete. The proactive APRA delay briefing (CBM.5.1.3) is in the schedule at 0%. Source comments say a six month minimum pre-notification applies and that board members carry personal liability.

The notification date is fixed against the 15 Mar 2027 baseline, while the integration build behind it is running late. The schedule gives the notification 130 working days of float, so the schedule logic does not show it driving go-live. The risk is regulatory: lodging a credible notification while integration status is behind. Whether the date can move is a question for APRA and the CRO, and the export does not say.

APRA and internal risk policy require the old and new systems to run together for three months (CBM.4.4.1, source comment). It follows UAT, which follows SIT, which follows the integration build.

SIT is dated to start 24 Dec 2026, 80 working days after baseline, and the parallel run is dated 14 Apr 2027 to 30 Jun 2027. Every one of these stages carries the same negative float (-80 days), so none has room to absorb a further slip.

The data quality audit found 340,000 anomalies: 180K duplicate or linked, 95K dormant and 65K with outdated beneficiary data. Duplicate account remediation (CBM.3.2.1, A. Osei) is 20% complete and finishes 8 Sep 2026, against a baseline of 28 Jul 2026. Customer-linked duplicates need manual review (source comment).

The task has 90 working days of float, so it is not driving go-live in the schedule logic. Migration dry run 1 (CBM.3.3.5) depends on it and is dated 9 Sep 2026, against a baseline start of 3 Aug 2026. Migrating anomalous financial data is not permitted, so the remediation must finish before cutover.

The plan for 2.1M customers (CBM.5.3.1, K. Barrett) is dated to start 4 May 2026 and is 0% complete. The source comment says it needs 8 weeks, and that the communications team is unaware it is assigned to them.

Customer notifications (CBM.5.3.3) are dated from 1 Oct 2026, and the plan has 126 working days of float. The risk is a start that slips because the owner team has not been briefed, which would leave less than the 8 weeks the plan needs.

The gap cannot be closed with internal hires alone in the time available.

Owner: Program Director (S. Okafor), proceeding on approval of Decision 1. Due: 1 May 2026. Engage a specialist integration consultancy under a fixed scope to complete the integrations with no developer. The source comment estimates $4M to $6M for 4 to 6 FTE over three months.

Do not wait for the notification date to raise the timeline risk.

Owner: CRO (M. Andersen), proceeding on endorsement of Decision 2. Due: 29 May 2026. Hold the briefing (CBM.5.1.3) with the current position, the cause of delay and the mitigation under way, before the CPS 234 notification is prepared. Disclose the delay in the Q2 2026 APRA progress report as well.

The plan needs 8 weeks and its owner team has not been briefed.

Owner: Legal and Regulatory Lead (K. Barrett). Due: 4 May 2026, the planned start. Brief the communications lead on the cutover timeline, the parallel run window and the 2.1M customer scope, so the plan starts on its dated day.

The task is six weeks behind and customer-linked duplicates need manual review.

Owner: Data Migration Lead (A. Osei). Due: 29 May 2026. Split the 180K duplicates by whether they have active transactions, and add manual review capacity for those first. Report the count remaining weekly against the 28 Jul 2026 baseline finish.

Three senior engineers left in Q1, and the build cannot absorb more departures.

Owner: Integration Lead (V. Chakraborty). Due: 29 May 2026. Complete knowledge transfer from the departing engineers (CBM.2.3.x, 50% complete) and agree retention steps for the engineers who remain.