You have tested JSONPlaceholder and ReqRes.in. Now apply the same skills to two more APIs. This builds muscle memory. The more APIs you test, the faster you get at reading documentation, writing schemas, and catching edge cases.
Restful-Booker (https://restful-booker.herokuapp.com) is a hotel booking API with real auth. It requires a token for PUT/PATCH/DELETE operations. This makes it perfect for practicing authentication testing.
{
"firstname": "Rahul",
"lastname": "Sharma",
"totalprice": 150,
"depositpaid": true,
"bookingdates": {
"checkin": "2024-06-01",
"checkout": "2024-06-05"
},
"additionalneeds": "Breakfast"
}Swagger Petstore (https://petstore.swagger.io) is the classic API testing playground. It has Swagger/OpenAPI documentation, which is what you will see in most real-world projects.
Pick either Restful-Booker or Petstore and build a complete REST Assured framework with:
Restful-Booker is the better interview story because it has real auth. When asked "how do you handle authentication in your framework?" you can describe the token flow: POST /auth to get a token, store it in BaseTest, inject it as a Cookie header in all subsequent requests.
These free APIs go down sometimes. If an API is not responding, wait 30 minutes and try again. Or use a different one. The practice is in writing the tests, not in any specific API. The patterns transfer.
Key Point: Practice on Restful-Booker (real auth) and Swagger Petstore (Swagger docs). Build a mini framework for one of them. The more APIs you test, the faster and more confident you get.