UX/UI & System Architecture Designs
This deliverable transforms the abstract requirements in your PRD into concrete visual designs and technical architecture blueprints.
1. User Flows & Journey Maps
Before drawing any screens, map out the logical path a user takes to achieve their goal. This ensures no dead-ends or missing states.
Onboarding Flow
- • Sign up, email verification, initial profile setup.
Checkout Flow
- • Cart review, shipping details, payment processing, success confirmation.
What to Deliver
- → Flowcharts using standard symbols
- → Edge cases and error states mapping
2. Wireframes & High-Fidelity UI/UX
Visual designs give every stakeholder a shared mental model of the product before development begins. They dramatically reduce costly redesigns later.
Low-Fidelity Wireframes
- • Simple sketches or grayscale mockups
- • Focus on layout and information hierarchy
- • Tools: Balsamiq, Whimsical, FigJam
High-Fidelity UI Designs
- • Pixel-perfect, color-accurate screen designs
- • Interactive prototypes with click flows
- • Tools: Figma, Adobe XD
What to Deliver
- → Screen-by-screen visual designs for all pages
- → User flow prototypes (Figma links)
- → Responsive breakpoints
- → Accessibility annotations
3. System Architecture Diagram
A system architecture diagram maps out how all technical components interact. It gives engineers a blueprint for structuring the codebase.
Frontend
Client-side layer — Next.js, React, Vue. Renders the UI and calls APIs.
Backend
Server-side logic — NestJS, Express, FastAPI. Processes business rules.
Cloud & Infra
Hosting & scaling — AWS, GCP, Azure. Manages containers and deployments.
Patterns to Document
- → Monolith vs. Microservices
- → API gateways
- → Message queues (Kafka)
- → Caching (Redis)
- → Auth flow (OAuth2)
4. ERD & Database Schema
An Entity-Relationship Diagram (ERD) maps data entities. It is the blueprint database engineers use before writing SQL.
| Entity | Relationship | Cardinality |
|---|---|---|
| User | has many | Orders (1:N) |
| Order | contains many | Products (N:M) |
| Product | belongs to | Category (N:1) |
password
user_id (FK)
total
Recommended ERD Tools
dbdiagram.io, DrawSQL, Lucidchart, pgModeler, MySQL Workbench.
5. API Specifications
API specs define the contract between frontend, backend, and third-party services, allowing teams to work in parallel.
Endpoint Definitions
- • HTTP Method & Path
- • Request body schema
- • Response structure
- • Auth requirements
- • Rate limits
Third-Party Specs
- • Payment gateways (Stripe)
- • SMS/Email (Twilio)
- • OAuth (Google/Meta)
- • Analytics (Mixpanel)
Documentation Tools
Swagger UI / OpenAPI (industry standard), Postman, Insomnia, Stoplight.