Executive Roadmap
● Live
✦ Cherry Analysis
⚠ Amber
APRA CPS 234
Programme Summary
Nexus Bank's core banking migration is AMBER — 28 days behind baseline with a regulatory deadline that cannot move. The integration build is the critical path and is understaffed following 3 senior engineer departures in Q1. The APRA CPS 234 pre-notification deadline of September 2026 is now at risk — a breach carries personal board liability. 129 critical integrations have no assigned developer. If the resource gap is not closed in the next 30 days, the March 2027 go-live becomes unachievable without regulatory impact.
Programme timeline · Jan 2025 → Jun 2027 · Smartsheet
⚠ APRA CPS 234 notification required 6 months pre-cutover
Workstream Overview
Phase 1 — Discovery & Architecture
Jan 2025 → Jun 2025
100%
Current state assessment — 1,200+ integrations catalogued100%
Target architecture design100%
Vendor selection — Temenos T24 contracted100%
✓ All discovery complete. Temenos T24 selected and contracted. 1,247 integrations catalogued — 340 classified as critical path for cutover.
Phase 2 — Build, Configure & Migrate
Jul 2025 → Sep 2026
44%
Core platform configuration (Temenos T24)72%
Integration build — 340 critical · 129 unassigned ⚠38%
Customer data migration — 2.1M records25%
Parallel run environment setup10%
⬤ Integration build 28 days behind. 129 of 340 critical integrations have no assigned developer. 3 senior engineers resigned in Q1 — backfill ongoing. Integration completion is the critical path to UAT start.
Phase 3 — Testing & Parallel Run
Sep 2026 → Jan 2027
3%
System Integration Testing (SIT)0% ⚠
User Acceptance Testing (UAT)0%
Parallel run — both systems live (3 months, non-negotiable)0%
APRA CPS 234 notification & approval0% ⚠
⚠ APRA CPS 234 requires minimum 6-month pre-notification of material IT changes. Notification must be lodged by Sep 2026. Integration delays now put this date at risk. Regulatory breach of notification requirement carries board-level personal liability.
Phase 4 — Cutover & Hypercare
Feb 2027 → Jun 2027
0%
Weekend cutover execution — 2.1M customers0%
Legacy system decommission0%
Hypercare — 90 days rollback maintained0%
2.1 million customers. The cutover window is a single weekend. Rollback capability must be maintained for 90 days post go-live. Customer communication plan not yet started.
Risk & Issue Analysis
✦ Cherry Analysis3
Critical
2
High
APRA
Regulatory — board liability
2.1M
Customers affected at cutover
⚖️
APRA CPS 234 notification — Sep 2026 deadline at risk from integration delays
APRA's CPS 234 standard requires authorised deposit-taking institutions to notify APRA of material information asset changes a minimum of 6 months before implementation. For a March 2027 go-live, notification must be lodged by September 2026. The current 28-day integration delay means the programme will not have sufficient testing confidence to lodge a credible notification by September. Failure to notify APRA appropriately exposes Nexus Bank board members to personal liability under APRA enforcement powers.
🔴
129 critical integrations unassigned — 3 senior engineers departed Q1
Of 340 integrations on the critical path, 129 have no developer assigned. Three senior integration engineers resigned in Q1 citing workload. The backfill process has produced 2 new hires who are currently onboarding but will not be productive for 6–8 weeks. At current velocity with current staffing, the integration build will not be complete until December 2026 — 3 months after the SIT start date — making UAT and parallel run impossible before March 2027.
🔴
3-month parallel run is non-negotiable — compresses every upstream phase
APRA and Nexus Bank's own risk framework require a minimum 3-month parallel run of old and new systems before decommissioning the legacy platform. This is non-negotiable. Working backward from the March 2027 go-live: parallel run must start by December 2026, UAT must be complete by November 2026, SIT must start by September 2026. The current integration completion trajectory misses the September SIT start date by approximately 10 weeks.
🟡
Customer data migration — 2.1M records, data quality assessment revealed 340K anomalies
The customer data migration audit identified 340,000 records with data quality anomalies — duplicate accounts, outdated beneficiary details, and dormant accounts with unreconciled balances. Each category requires a different remediation approach. The migration team has a plan but it requires 6 additional weeks beyond the current timeline. These records must be resolved before cutover — migrating anomalous customer financial data into a new system during a live cutover is not permissible.
🟡
Customer communications plan not started — 2.1M customers need 8 weeks notice
The cutover will affect every Nexus Bank customer. The customer communication plan — covering digital banking downtime, branch operating hours, payment processing windows, and dispute resolution during parallel run — has not been drafted. Banking regulations require customers to be notified of material system changes. The communications team estimates 8 weeks to develop, approve, and deploy. This work needs to start by July 2026 to be ready for the December parallel run communications.
Suggested Actions
✦ PrioritisedRegulatory deadline is fixed. All actions below are calibrated to protect the APRA notification date and March 2027 go-live.
1
Engage external integration specialists immediately — close the 129-task gap within 60 days
The integration build gap cannot be closed with internal hires alone in the available time. Engage a specialist integration consultancy — Deloitte, Accenture, or a Temenos T24 specialist — under a fixed-scope contract to complete the 129 unassigned integrations. This will cost approximately $4–6M but protects a $340M programme and avoids regulatory breach. Present the business case to the board this week.
2
Engage APRA proactively — inform them of the delay and your mitigation plan now
Do not wait until September to surface the timeline risk with APRA. Engage the APRA relationship manager this month with a transparent briefing on the current position, the cause of the delay, and the specific mitigation actions underway. APRA responds far better to proactive disclosure than to discovering issues during supervision. Early engagement may also create space to negotiate the notification timeline if mitigation is demonstrably underway.
3
Start customer communications planning now — do not wait for UAT
The comms team needs 8 weeks. July 2026 is the latest start. That is 10 weeks from today. Brief the communications lead this week on the cutover timeline, parallel run window, and customer impact scope. Regulatory comms for a banking system migration require legal review, ASIC alignment, and executive approval — all of which take time that doesn't exist if you start in July.
4
Triage the 340K data anomalies — classify and scope the remediation this week
Not all 340,000 anomalies carry equal risk. Triage them by category and impact: dormant accounts with zero balance can be handled post-migration, duplicate accounts with active transactions cannot. A triage classification this week will tell you how much remediation effort is truly blocking the cutover vs what can be managed in parallel. This converts an unknown into a quantified risk with a concrete plan.
5
Address engineer retention — exit interview findings must be acted on now
Three senior engineers left in Q1. The exit interviews almost certainly identified root causes — workload, management, compensation, or culture. Whatever the findings are, act on them publicly and demonstrably now. Losing two more senior integration engineers in the next 6 months would make the March 2027 go-live effectively impossible. Retention is cheaper than replacement at this stage of a programme.
Workstream Dashboards
✦ Auto-filtered · SmartsheetIntegration Build — 340 Critical Integrations
38%
28d behind · understaffed
⬤ 129 of 340 critical integrations have no assigned developer. At current velocity: completion Dec 2026 — 3 months after SIT must start.
DescriptionStartEndAssignedProgressStatus
Core banking API layer (T24)
Jul 2025
Oct 2025
V. Chakraborty
100%
DoneInternet banking portal
Oct 2025
Feb 2026
Digital team
100%
DoneMobile banking app integration
Feb 2026
Jun 2026
Digital team
75%
In progressPayment systems (NPP, BPAY, SWIFT)
Mar 2026
Aug 2026
V. Chakraborty
45%
In progressThird-party integrations (129 unassigned)
Ongoing
Sep 2026 ⚠
VACANT
8%
UnderstaffedBranch & ATM network
Apr 2026
Jul 2026
Ops team
30%
In progressRegulatory reporting feeds (APRA)
Jun 2026
Sep 2026
V. Chakraborty
0%
Not started⚠ Relevant Risks
🔴
129 critical integrations unassigned — 3 senior engineers departed Q1
At current velocity the integration build completes Dec 2026 — 3 months after SIT must start. Makes March 2027 go-live unachievable.
🔴
3-month parallel run is non-negotiable — compresses all upstream phases
Working backward: parallel run Dec 2026, UAT Nov 2026, SIT Sep 2026. Integration delays already miss the Sep start by 10 weeks.
→ Suggested Actions
1
Engage external integration specialists immediately
Engage Deloitte, Accenture, or a Temenos T24 specialist to close the 129-task gap within 60 days. ~$4–6M cost protects a $340M programme.
This weekBoard approval5
Address engineer retention — act on exit interview findings now
Three senior engineers left in Q1. Losing more makes the go-live impossible. Retention is cheaper than replacement at this stage.
This monthCustomer Data Migration — 2.1M Records
25%
anomalies being resolved
DescriptionStartEndAssignedProgressStatus
Data catalogue & schema mapping
Jul 2025
Sep 2025
A. Osei
100%
DoneData quality audit — 2.1M records
Sep 2025
Dec 2025
Temenos
100%
Done — 340K issuesAnomaly triage & classification
Jan 2026
May 2026
A. Osei
60%
In progressDuplicate account remediation
Feb 2026
Jul 2026
A. Osei
20%
ComplexMigration dry run 1
Aug 2026
Aug 2026
Temenos
0%
Not startedMigration dress rehearsal
Nov 2026
Nov 2026
A. Osei
0%
Not started◆ Production migration — cutover weekend
Mar 2027
Mar 2027
All teams
0%
Go-live⚠ Relevant Risks
🟡
340K data anomalies — remediation adds 6 weeks to migration timeline
Duplicate accounts with active transactions must be resolved before cutover. Migration of anomalous financial data during a live cutover is not permissible.
→ Suggested Actions
4
Triage the 340K data anomalies this week
Classify by type and impact — dormant zero-balance accounts can be handled post-migration. Quantify what truly blocks cutover vs. what can run in parallel.
This weekData migrationTesting & Parallel Run
3%
planning only
⚠ SIT must start Sep 2026. Integration build delays mean this date is at risk. 3-month parallel run is non-negotiable — it sets all upstream deadlines.
DescriptionStartEndAssignedProgressStatus
Test strategy & plan
Mar 2026
May 2026
L. Ferreira
40%
In progressSIT environment setup
Jun 2026
Aug 2026
IT team
5%
Early stageSystem Integration Testing (SIT)
Sep 2026
Oct 2026 ⚠
L. Ferreira
0%
At riskUser Acceptance Testing (UAT)
Oct 2026
Nov 2026
Business teams
0%
Not startedParallel run — both systems live
Dec 2026
Mar 2027
All teams
0%
3 months req.◆ Go-live — cutover weekend
Mar 2027
Mar 2027
Programme
0%
Target⚠ Relevant Risks
🔴
3-month parallel run is non-negotiable — sets all upstream dates
Working backward: parallel run must start Dec 2026, UAT complete Nov 2026, SIT start Sep 2026. Integration delays already miss Sep start by 10 weeks.
→ Suggested Actions
3
Start customer communications planning now — do not wait for UAT
The comms team needs 8 weeks. July 2026 is the latest start — 10 weeks from today. Regulatory comms require legal review, ASIC alignment, and executive approval.
This week2.1M customersRegulatory & Compliance
⚠
APRA deadline at risk
⬤ APRA CPS 234 notification must be lodged by September 2026. Integration delays put this at risk. Board members carry personal liability for regulatory breach.
DescriptionStartEndAssignedProgressStatus
APRA initial programme notification
Jan 2025
Jan 2025
M. Andersen
100%
DoneCPS 234 compliance assessment
Apr 2025
Jun 2025
K. Barrett
100%
DoneQuarterly APRA progress reporting
Jan 2025
Ongoing
M. Andersen
75%
OngoingCPS 234 pre-cutover notification
Aug 2026
Sep 2026 ⚠
M. Andersen
0%
At riskProactive APRA delay briefing
NOW
This month
M. Andersen
0%
Not doneCustomer regulatory communications
Jul 2026
Mar 2027
K. Barrett
0%
Not startedPost go-live APRA report
Mar 2027
Jun 2027
M. Andersen
0%
Not started⚠ Relevant Risks
⚖️
APRA CPS 234 notification — Sep 2026 deadline at risk from integration delays
Failure to notify APRA appropriately exposes Nexus Bank board members to personal liability under APRA enforcement powers.
→ Suggested Actions
2
Engage APRA proactively — inform them of the delay now
Do not wait until September. APRA responds far better to proactive disclosure. Early engagement may create space to negotiate the notification timeline.
This monthRegulatory