Future State Architecture

USE CASE: LARGE RETAIL BANK – DIGITAL CHANNEL MODERNIZATION

🔹 Business Context

A large retail bank wants to “modernize” its digital channels (internet banking + mobile apps).

Constraints:

• Heavy regulatory compliance (RBI, PCI)

• Legacy core banking system (cannot change easily)

• Multiple future initiatives planned over 3–5 years:

  • New mobile app

  • Open banking APIs

  • Partner integrations (fintechs)

  • AI-based personalization (future)

They explicitly say:

“We don’t want to keep changing the architecture every time.”

STEP 1: IDENTIFY CORE PLATFORM CAPABILITIES (STABLE FOR YEARS)

These are non-negotiable, long-lived capabilities.

Core Platform Layer (Built Once, Reused Everywhere)

1️⃣ Identity & Security

• Authentication, authorization

• MFA, RBAC

• Centralized audit logging

2️⃣ Integration Layer

• API Gateway

• Standardized REST / event contracts

• Throttling, versioning, security policies

3️⃣ Data & Compliance

• Central logging

• Data masking

• Audit trails

• Encryption at rest & in transit

4️⃣ Observability & Reliability

• Central monitoring

• Alerting

• SLA tracking

5️⃣ DevOps & Platform Engineering

• CI/CD pipelines

• Environment provisioning

• Infrastructure as Code

👉 Key Point:These capabilities rarely change and protect the platform investment.

STEP 2: BUILD A STABLE CORE PLATFORM (AZURE EXAMPLE)

Azure Implementation (example, not tool-pushing):

• Azure AD / Entra ID for identity

• Azure API Management for gateway

• AKS for platform workloads

• Azure Monitor + App Insights

• Azure DevOps CI/CD

This becomes the bank’s digital foundation.

STEP 3: DEFINE EXTENSION POINTS (WHERE CHANGE IS EXPECTED)

Now comes the smart part.

Extension Points (Designed for Change)

1️⃣ Channel Extensions

• Mobile app

• Web app

• Partner portals➡️ All consume APIs — no direct backend coupling

2️⃣ Business Capability Extensions

• Payments

• Loans

• Customer profile

• Notifications

Each capability:

• Independently deployable

• Clear API contracts

• Can be replaced or enhanced later

3️⃣ Future Innovation Extensions

• AI personalization

• Open banking APIs

• Fintech partner onboarding

These plug into the same core platform, not custom pipelines.

STEP 4: HOW THIS PREVENTS FUTURE REWORK (KEY INTERVIEW POINT)

Example: 3 Years Later

The bank wants to:

• Launch Open Banking APIs

• Partner with fintechs

What changes?✔ New APIs added✔ Partner onboarding workflows

What does NOT change?❌ Security model❌ Compliance❌ CI/CD❌ Monitoring❌ Core integration patterns

👉 Result:No architectural rewrite. Only extensions.

STEP 5: Summary

“In one engagement with a large retail bank, we identified core platform capabilities like security, integration, compliance, and observability as long-lived investments. We built these as a stable platform layer. On top of this, we designed clear extension points for digital channels, business capabilities, and future innovation such as open banking and AI. Three years later, when the bank introduced fintech partnerships, they extended the platform without touching the core architecture. This approach protected their investment and allowed controlled evolution rather than repeated redesign.”