I am building a config-driven multi-step form workflow engine that demonstrates frontend system thinking: state machines, async validation, failure handling, and scalability.

Big Picture: What are we actually building?

We are NOT building: ->a form ->a simple React app We are building a Frontend Workflow Engine. That means: A reusable system that can run any multi-step process (onboarding, loan application, signup, survey) without rewriting logic.

The UI is just a viewer. The engine is the brain.🧠

The core problem we are solving (real-world) In real companies, forms fail because: i. State is scattered ii. Validation is inconsistent iii. Edge cases break flows iv. Changes are risky

Example failure: User refreshes → data lost API fails → UI stuck Step order changes → code breaks

Lets Solve this problem. Shall we?

Designing the System⛑️

🧠 Layer 1 — Contracts (WHAT exists) Defines: What states are allowed What a step looks like What a field looks like 👉 This is types.ts

⚙️ Layer 2 — State Machine (HOW it behaves) Defines: Which state can go to which What happens on NEXT / ERROR / RETRY 👉 This is stateMachine.ts

🧩 Layer 3 — Engine (WHO controls the flow) Defines: When validation runs When state updates When data is saved 👉 This is engine.ts

🔌 Layer 4 — Hook (HOW UI talks to system) Defines: Simple API for components

We then move to next feature of this Form Engine Flow, i.e "RESTORE FROM SAVED STATE". 🎯 Goal : Refresh the page → workflow resumes exactly where it left off. useWorkflow.ts (It owns state) It already mediates UI ↔ engine

Persistence is a state concern, not UI or engine Hide complexity Post this, there will be Pure rendering