Module 1

Testing Foundations

Test what users see, how systems communicate, and whether important product rules hold.

153 minutes across 15 published lessons

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Lessons in This Module

Lesson 1
What Testing Is Trying to Prove
Testing produces evidence that specified behaviour holds under selected conditions and exposes uncertainty that remains outside those conditions. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 2
Testing Interfaces, APIs, and Business Logic
Test what users see, how systems communicate, and whether the product’s rules continue to hold under incorrect inputs.
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Lesson 3
Testing a User Interface
User interface testing checks whether people can perceive, understand, operate, and recover from the product's visible interactions. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 4
Testing Responsive Design
Responsive testing checks layout, content priority, controls, and input behaviour across representative viewport sizes and devices. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 5
Testing Forms and Validation
Form testing verifies accepted input, rejected input, feedback, preservation, submission, and the same rules at the server boundary. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 6
Testing Loading and Failure States
Loading and failure testing verifies what the user sees and can safely do while work is delayed, unavailable, partial, or unsuccessful. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 7
What an API Endpoint Is
An API endpoint is a defined network address and operation through which a client requests or changes a specific capability. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 8
Testing Endpoints with Postman
Postman is a client for constructing, sending, organising, and inspecting API requests independently of the product interface. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 9
Successful, Invalid, and Unauthorised Requests
Request testing distinguishes valid operations from malformed, impossible, unauthenticated, and insufficiently authorised attempts. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 10
Testing Complete User Workflows
Workflow testing follows a user goal across screens, services, rules, messages, and stored state from starting condition to final outcome. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 11
Boundary Values and Impossible States
Boundary testing examines values at and around limits, while impossible-state testing challenges combinations the product should never permit. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 12
Duplicate Actions and Race Conditions
Duplicate actions repeat an intended operation, while race conditions make results depend on the timing of concurrent work. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 13
Testing Permissions
Permission testing verifies that each identity can perform only allowed actions on allowed resources, including through direct requests. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 14
Human and AI-Generated Logic Mistakes
Logic mistakes arise from misunderstood rules, missing conditions, incorrect sequencing, or false assumptions regardless of whether code was written by a person or model. Learn the founder decision, practical evidence, and warning signs that matter.
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Lesson 15
Preparing an MVP Test Plan
An MVP test plan lists priority claims, environments, data, steps, expected results, owners, evidence, and release decisions. Learn the founder decision, practical evidence, and warning signs that matter.
Open Lesson

Lessons in This Module

Lesson 1

What Testing Is Trying to Prove

Testing produces evidence that specified behaviour holds under selected conditions and exposes uncertainty that remains outside those conditions. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 2

Testing Interfaces, APIs, and Business Logic

Test what users see, how systems communicate, and whether the product’s rules continue to hold under incorrect inputs.

Open Lesson

Lesson 3

Testing a User Interface

User interface testing checks whether people can perceive, understand, operate, and recover from the product's visible interactions. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 4

Testing Responsive Design

Responsive testing checks layout, content priority, controls, and input behaviour across representative viewport sizes and devices. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 5

Testing Forms and Validation

Form testing verifies accepted input, rejected input, feedback, preservation, submission, and the same rules at the server boundary. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 6

Testing Loading and Failure States

Loading and failure testing verifies what the user sees and can safely do while work is delayed, unavailable, partial, or unsuccessful. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 7

What an API Endpoint Is

An API endpoint is a defined network address and operation through which a client requests or changes a specific capability. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 8

Testing Endpoints with Postman

Postman is a client for constructing, sending, organising, and inspecting API requests independently of the product interface. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 9

Successful, Invalid, and Unauthorised Requests

Request testing distinguishes valid operations from malformed, impossible, unauthenticated, and insufficiently authorised attempts. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 10

Testing Complete User Workflows

Workflow testing follows a user goal across screens, services, rules, messages, and stored state from starting condition to final outcome. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 11

Boundary Values and Impossible States

Boundary testing examines values at and around limits, while impossible-state testing challenges combinations the product should never permit. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 12

Duplicate Actions and Race Conditions

Duplicate actions repeat an intended operation, while race conditions make results depend on the timing of concurrent work. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 13

Testing Permissions

Permission testing verifies that each identity can perform only allowed actions on allowed resources, including through direct requests. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 14

Human and AI-Generated Logic Mistakes

Logic mistakes arise from misunderstood rules, missing conditions, incorrect sequencing, or false assumptions regardless of whether code was written by a person or model. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson

Lesson 15

Preparing an MVP Test Plan

An MVP test plan lists priority claims, environments, data, steps, expected results, owners, evidence, and release decisions. Learn the founder decision, practical evidence, and warning signs that matter.

Open Lesson