TOE: Introduction & Overview

These are the 4 repos that matter for TOE. The workflow-era repos (workflow-service, borrower-service, applicant-portal) still exist but are not part of this architecture.

Source Files

Wizard→borrower-interactions-ui/src/application/

Portal→borrower-interactions-ui/src/tasks/

Auth source→borrower-auth-ui/src/

Core→marketplace/lc/

Engines→marketplace/lc/engines/

Reactor→marketplace/lc/reactor/

File model→marketplace/lc/model/file.py

Cortex source→cortex-lender-checker-ui/src/file/

Every Data Change Triggers a Full Reactive Loop

The contract is satisfy codes and policy YAML.

Data Change

Borrower enters or updates data — income, assets, property, consent

Reactor Cascade

Recalculates derived fields — DTI · CLTV · Credit Score

Decision Engine

Evaluates policy YAML → satisfy codes · Tri-logic: True · False · Unknown

Stage Auto-Advance

All requirements pass → stage advances · Strategy handlers fire (automated actions triggered by policy rules): pricing, offers

UI Updates

Borrower UI and Lender UI reflect new state immediately — loop restarts on next change

ℹ️

The contract between frontend and backend: satisfy codes. Policy YAML drives the flow — the same Borrower UI codebase adapts dynamically per product.

Source Files

Process→lc/reactor/process.py

DTI→reactor/functions/calculate_dti.py

CLTV→reactor/functions/calculate_cltv.py

Eval→lc/engines/decision/eval/eval_req.py

FE contract→src/application/satisfy-code-definitions.ts

Strategy→lc/engines/decision/schema/strategy.py

Dispatch→lc/engines/decision/schema/dispatch.py

Three Systems Own the Full Loan Lifecycle

Borrower UI captures data, marketplace evaluates it, Lender UI acts on it.

Borrower

Borrower Interactions UI

Wizard • Portal • Auth

8 screens, typed field component library

Task handlers, documents, messages

Cognito inline signup • session management

Backend

Marketplace Backend

Decision • Reactor • Pricing • YAML

Python/Flask — marketplace repo

YAML → satisfy codes (tri-logic)

Event-driven cascade, derived values

Rates, APR, payments, fees

6 stages, per-company rules

Lender

Lender UI

Fast Track • Tasks • Funding

Lender-facing dashboard

Stage tracker + rule cards

Orders, uploads, approvals

Core direct / Method paths

ℹ️

The 6 policy stages that drive the lifecycle: application → prequal → credit_verification → intent_to_proceed → initial_underwriting → fast_track_complete.

Source Files

Screens→src/application/screens/

Portal→src/tasks/portal-page.tsx

Signup→src/pre-auth/signup-screen.tsx

Decision→lc/engines/decision/api.py

Reactor→lc/reactor/process.py

Pricing→lc/engines/pricing/api.py

Summary→src/file/summary/

Orders→src/orders/

Funding→src/file/funding-disbursement/

Navigation

Next: System Architecture

Decks Map the Full TOE Stack

Four Generations: Manual Orders → Decision-Driven TOE

The Entire TOE Stack

Every Data Change Triggers a Full Reactive Loop

Three Systems Own the Full Loan Lifecycle

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