Uploaded December 2025 | Updated September 2026, 2 weeks ago
In this video, you'll learn how to write user stories for payment features while understanding the fundamentals of pricing models and payment processing APIs.
What You'll Learn:
1. Different pricing models: Subscription, one-time, and usage-based
2. Why no one codes payment processing from scratch
3. How Stripe APIs handle payment complexity for you
4. Writing scenario-based acceptance criteria for complex features
5. Creating comprehensive user stories for pricing plans
Key Concept: Payment APIs Work Like AI APIs
Just like you didn't code AI from scratch, you don't code payments from scratch. Companies like Stripe provide APIs that handle all the complexity—currency conversion, security, fraud detection, compliance—while you just call their API.
Pricing Models Explained:
1. Subscription-based (What we're building)
2. Recurring fees: monthly or annual, ideal for SaaS, membership sites, ongoing services
3. One-time payments: single payment for lifetime access, works for tools, templates, standalone products
Usage-based pricing:
Pay for what you use (API calls, storage, etc.), common in infrastructure and developer tools
Why Scenario-Based Acceptance Criteria?
Payment features are complex. Scenarios give you tighter control over LLM behavior, ensuring reliable implementation of critical functionality like billing and plan comparisons.
LLM Context Windows Are Larger Now
Don't worry about being too prescriptive. Modern LLMs can handle detailed specifications as long as you focus on one feature at a time.
I built this for our public service community. If you find it useful, share it across the public service, please. And when you build something, tag me on LinkedIn (https://linkedin/in/yongkiat), and I'd love to see what you create!
Let's grow together. See you in the videos!
Instagram: / rogue.teacher.sg
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User Story: for this video, the user story is really comprehensive and too long to be placed within YouTube comments. I've created a Google doc link at: docs.google.com/document/d/1CwIrDWOKLrxST3vMDfyez2smEaZdH-bQOwkfCZWQXRA/edit?usp=sharing. Contact me if it doesn't work, I'll see you in the videos!
In this video, you'll learn how to write user stories for payment features while understanding the fundamentals of pricing models and payment processing APIs.
What You'll Learn:
1. Different pricing models: Subscription, one-time, and usage-based
2. Why no one codes payment processing from scratch
3. How Stripe APIs handle payment complexity for you
4. Writing scenario-based acceptance criteria for complex features
5. Creating comprehensive user stories for pricing plans
Key Concept: Payment APIs Work Like AI APIs
Just like you didn't code AI from scratch, you don't code payments from scratch. Companies like Stripe provide APIs that handle all the complexity—currency conversion, security, fraud detection, compliance—while you just call their API.
Pricing Models Explained:
1. Subscription-based (What we're building)
2. Recurring fees: monthly or annual, ideal for SaaS, membership sites, ongoing services
3. One-time payments: single payment for lifetime access, works for tools, templates, standalone products
Usage-based pricing:
Pay for what you use (API calls, storage, etc.), common in infrastructure and developer tools
Why Scenario-Based Acceptance Criteria?
Payment features are complex. Scenarios give you tighter control over LLM behavior, ensuring reliable implementation of critical functionality like billing and plan comparisons.
LLM Context Windows Are Larger Now
Don't worry about being too prescriptive. Modern LLMs can handle detailed specifications as long as you focus on one feature at a time.
I built this for our public service community. If you find it useful, share it across the public service, please. And when you build something, tag me on LinkedIn (https://linkedin/in/yongkiat), and I'd love to see what you create!
Let's grow together. See you in the videos!
Instagram: / rogue.teacher.sg
---
User Story: for this video, the user story is really comprehensive and too long to be placed within YouTube comments. I've created a Google doc link at: docs.google.com/document/d/1CwIrDWOKLrxST3vMDfyez2smEaZdH-bQOwkfCZWQXRA/edit?usp=sharing. Contact me if it doesn't work, I'll see you in the videos!
