Coexistence Strategy: Monolith and MFE (Module Federation) Estate (Coexistence Strategy Monolith And Mfe Estate)

Coexistence Strategy: Monolith and MFE (Module Federation) Estate

Publish a sequence: auth → booking → shared UI; keep control plane until boundaries harden.

migrate by boundary, not by fashion

Göç sırası: net sınır önce, moda sonra.

Concepts, defined where they first appear

📦 Control Plane
Surface that binds map, content, notifications, and integration edges.

📦 Ops Monolith
Broad panel — often CRA — living outside the federated estate.

📦 Push Admin
Admin for campaign/push notifications — not the snackbar remote.

📦 ERP Edge
Integration edge where ERP sync lives under unreliable boundaries.

Teams that blur these concepts confuse UI state with integration truth.

Shape of the problem

Publish a sequence: auth → booking → shared UI; keep control plane until boundaries harden.

migrate by boundary, not by fashion

The split that works

Göç sırası: net sınır önce, moda sonra.

migrate by boundary, not by fashion
        ↓
   explicit contract

Where production breaks

Incidents grow when radius, identity, or deploy assumptions stay implicit. Make the contract visible and reversible.

The mappings that get confused most often

❌ One app is always safer
✓ Without clear boundaries, one app is more fragile

❌ Keep config hardcoded
✓ Radius, remote URLs, and expose paths are operational contracts

❌ Vendor/API truth is UI state
✓ Vendor feed is evidence; ops state is a decision

A checklist for auditing your own system

1. Write the ownership boundary for this surface in one sentence.
2. If this contract changes, who deploys?
3. On timeout or vendor delay, what does the UI show?
4. Do you test embedded and standalone paths separately?
5. Deny-list check: any vendor/domain leakage in copy?

What to take away from this part

1. Contracts must be visible: expose paths, radius, ticket state, or remote URLs.
2. The gap between UI and external systems is a design choice, not a bug.
3. Independent deploy means independent rollback.

The boundary you hide will find you in production.