AI

ACE AI Startup Bootcamp

Designing a Payment Service

πŸ“– View Session 9 practice lesson plan ← Return to Curriculum page
Day 9 Designing a Payment Service Video + AI chatbot learning

Payment system design & external PG linkage and AI learning assistant

This is the 9th day of learning content to understand the entire flow from product selection to order creation, payment processing, and result storage, and to design state management, external PG integration, exception handling, and recovery strategies.

Target audience: Students who implemented a membership registration and authentication system
Required materials: Laptop, payment PG company test account (Stripe, PortOne, etc.)
Composition: 2 hours theory / 3 hours practice / 1 hour sharing
πŸ“– Go to Session 9 teaching plan

πŸš€ Day 9 Practice MVP Tasks Roadmap

Go to the entire Task board β†’
TASK 1
Planning

Task 1. Design payment flow

Cut out the complex double-step journey from product selection to payment and simplify it with a unified overlay three-step model.

Task 1 Entry to the lab
TASK 2
Exceptions

Task 2. Review payment failure scenarios

Measures are taken for each raw error, such as exceeding the limit and communication delay, and a disabled lock is set up to block the approval of duplicate hits.

Task 2 Entry to the lab
TASK 3
UX Audit

Task 3. Improve the payment experience

We implant detailed pricing receipts, reassuring security phrases, and refund policy anchor links into the payment window to eliminate phishing concerns.

Task 3 Entry to the lab
MISSION 1
Failure Guide

Mission 1. Respond to payment failure situations

We build a collection of messages to reassure users in case of asset fear situations such as forced shutdown of PG window and inspection failure.

Mission 1 Lab Entry
MISSION 2
Friction Audit

Mission 2. Direct inspection until purchase is completed

We simulate driving from product selection to completion page to correct peak departure risk points such as form reset.

Mission 2 Lab Entry

Day 9 lecture video

YouTube Recommended Lectures
This is a list of recommended YouTube lectures corresponding to the core topics of the Day 9 curriculum (payment flow, product/order/payment separation, PG integration, webhook processing, transaction). (Constructed of free lecture videos that allow external sharing and playback.)
πŸ“š Full list of lectures (5)
  • β–Ά
    1. Payment story told by Port One - Dictionary of PG terms (Port One)
    7:45
  • β–Ά
    2. 10-minute cut with payment integration. I'll explain everything in one go! (Port One)
    10:15
  • β–Ά
    3. Toss Payments | Link payments in 5 minutes (Tos Payments)
    5:30
  • β–Ά
    4. Implement regular (subscription) payment with Port One (Port One)
    8:20
  • β–Ά
    5. Database – understanding the concept of transaction (software old man’s lecture)
    12:45

Key takeaway notes

Day 9 Summary

Today's Key Goals

On Day 9, we collaborate with Codex AI payment partners to analyze disconnect points that cause user churn, and supplement financial error mitigation text, duplicate payment blocking, and trust badges.

  • Design the order-to-pay business flow: Design of state transitions such as order waiting, order completion, payment waiting, payment completion, etc.
  • Development of external PG linking API: Payment request/approval processing through PG company SDK and API integration
  • Webhook data validation: Receiving and comparing webhooks between servers to prevent forgery and falsification of payment results
  • Transaction processing: DB rollback and restoration of order status when an error occurs during payment processing
  • Payment failure recovery strategy: Duplicate payment prevention (Idempotency) and cancellation payment processing
Study tip: Ask the AI ​​chatbot on the right, β€œWhy do you use webhooks when completing a payment and how do you verify it for security purposes?” or β€œHow do you ensure data integrity when a network error occurs during payment?” Ask the same question.