Architecture Documents
All formal EA artefacts — how they work, what's active, and what's in progress at Nexus Bank
Architecture Decision Record
ADR
Captures a significant technology or design decision: context, options considered, chosen direction, and rationale. One ADR per decision. Immutable once approved.
Architecture Principle
PRINCIPLE
A standing rule that guides all architecture decisions across the organisation. Broad, durable, and domain-independent. All ADRs and designs must be checked against active principles.
Design Document
DD
A project-level artefact submitted for EA review. Describes the intended technical approach, components, and integrations of a specific initiative. Scanned by the Principle Guardian.
Technology Radar Entry
TECH
Registers a technology (tool, platform, language) in the corporate technology radar. Required before a technology can be cited as "standard" in an ADR or Design Document.
Document Lifecycle — How artefacts move through the EA office
Draft
→
Team Review
→
EA Agent Check
→
Approved
/
Rejected
Approved
— superseded by newer version →
Superseded
- Every ADR must cite the principles it applies — the agent checks this automatically
- A Design Document must be submitted before a project moves to build phase
- Rejected documents are kept for audit — they explain what was considered and why it was declined
- A technology must have a Radar Entry before being proposed in an ADR
- Principles take precedence over ADRs — a conflicting ADR will be flagged
- Superseded ADRs remain visible; link to the decision that replaced them
Document Register — Nexus Bank
28 artefacts · last updated Apr 5, 2026| ID | Document | Type | Domain | Owner | Status | Updated |
|---|---|---|---|---|---|---|
| Active Principles (12) | ||||||
| P-01 |
Capability-Driven Investment
All projects map to an approved business capability
|
Principle | Business | Chief of Architecture | Active | Jan 2026 |
| P-02 |
Reuse Before Buy, Buy Before Build
Evaluate existing corporate solutions first
|
Principle | Business | Chief of Architecture | Violation open | Jan 2026 |
| P-03 – P-12 |
API-First · Zero-Trust · Single Source of Truth · UI Standards · Cloud-First · Corporate Solutions First · Mobile Security · Data Residency · Vendor Diversification · IaC
10 further active principles across Software, Security, Data, Cloud domains
|
Principle | Multiple | Chief of Architecture | Active | Various |
| Approved Architecture Decision Records (6) | ||||||
| ADR-001 |
Core Banking Migration to Cloud
Migrate to Mambu SaaS by Q3 2026
|
ADR | Cloud | Chief of Architecture | Approved | Jan 15, 2026 |
| ADR-002 |
API Gateway Standard — Kong
Centralised API management for all internal services
|
ADR | Software | Chief of Architecture | Superseded by ADR-006 | Feb 3, 2026 |
| ADR-003 |
Data Mesh Architecture — Databricks
Domain ownership model for analytics
|
ADR | Data | Chief of Architecture | Approved | Feb 20, 2026 |
| ADR-004 |
Mobile App Framework — React Native
Cross-platform mobile for iOS and Android
|
ADR | Software | Chief of Architecture | Approved | Mar 1, 2026 |
| ADR-005 |
Identity & Access Management — Okta
Standardised IAM across all digital channels
|
ADR | Security | Chief of Architecture | Approved | Mar 10, 2026 |
| ADR-006 |
API Gateway Standard — Kong (Reaffirmed)
All new APIs registered in Kong from Apr 2026
|
ADR | Software | Chief of Architecture | Approved | Apr 3, 2026 |
| In Process — Pending Decision (2) | ||||||
| ADR-007 |
CMS for Mobile Banking App
Proposed: Contentful — flagged by EA agent, AEM not evaluated
|
ADR | Software | Mobile App Team | Flagged — EA review | Apr 5, 2026 |
| ADR-008 |
Kafka Technology Registration
Draft initiated — confirms Apache Kafka in corporate tech radar for Data Platform v2
|
ADR | Data | Data Platform Team | Draft | Apr 3, 2026 |
| Design Documents (3) | ||||||
| DD-001 |
Mobile Banking App — Architecture Design
Covers React Native, Okta auth, Kong API, and CMS selection (flagged)
|
Design Doc | Software | Mobile App Lead | EA review in progress | Apr 4, 2026 |
| DD-002 |
Data Platform v2 — Architecture Design
Data mesh with Databricks, Kafka event streaming, Azure managed services
|
Design Doc | Data | Data Platform Lead | EA approved | Apr 2, 2026 |
| DD-003 |
Branch Digitalization — Discovery Brief
High-level scope only — full design document not yet submitted
|
Design Doc | Business | Branch Transformation Lead | Draft — awaiting EA intake | Mar 20, 2026 |
| Rejected / Not Approved (2) | ||||||
| ADR-R01 |
Custom Identity Broker — In-house IAM
Rejected: bespoke IAM solution proposed before Okta evaluation. Replaced by ADR-005.
|
ADR | Security | Security Team | Rejected | Feb 28, 2026 |
| DD-R01 |
Mobile Banking App — Initial Design (v0.1)
Rejected: missing API gateway reference, no security architecture section, IAM solution unspecified. Resubmitted as DD-001.
|
Design Doc | Software | Mobile App Lead | Rejected — resubmitted | Mar 15, 2026 |