Web APIs
Serve data and actions to websites, mobile apps, and partner systems.
Why .NET?
Build the services and business logic behind software people depend on.
Where .NET earns its place.
A useful application needs more than a screen. It needs secure APIs, clear business rules, integrations, tests, and a way to keep changing safely. .NET is one way teams build and maintain that server-side work.
Business workflows
Handle accounts, orders, permissions, and the rules around them.
Long-lived services
Run background tasks and integrations that teams need to test and operate.
Build an appointment booking API that can be trusted.
A service business needs customers to book available time slots. The screen is simple; the backend must handle two people choosing the same slot, invalid requests, and staff-only changes.
The constraint
A booking must never be confirmed twice for the same slot, even when requests arrive together.
Model the request
Define the booking data, validation rules, and who is allowed to create or cancel it.
Implement the endpoint
Use ASP.NET Core to save a booking and return clear success, validation, conflict, and permission responses.
Prove the behavior
Test normal bookings, duplicate slots, missing data, and an unauthorized cancellation.
What you would produce
A working endpoint, focused tests, and an explanation of how it handles a competing request.
Try an engineer’s decisionIs checking that a slot is free before inserting enough to prevent double booking?
No. Two requests can both pass that check before either writes. The database must enforce uniqueness or the operation must be coordinated transactionally; the API then turns the conflict into a useful response.
This is an illustrative task. The scope of a module is agreed before enrolment.
What you would learn by doing it.
Each part of the exercise connects a tool or concept to a decision you would make on a software team.
HTTP and API contracts
Choose request shapes, status codes, and useful error messages.
Frontend and backend teams can agree on behavior before wiring up a screen.Business rules and data
Keep booking rules in the service and protect consistency in the database.
The same rules hold when more clients or integrations use the API.Tests and debugging
Reproduce a failure, write a focused test, then fix the cause.
You can change an existing service without relying on guesswork.How real teams use .NET.
Published product and engineering sources show the kind of work this skill supports.
Stack Overflow
Its applications use .NET and cloud services to support the developer Q&A platform.
Read the source: .NET customer showcaseGeocaching
Its .NET web APIs support services for customers and partners.
Read the source: .NET customer showcaseThese organizations are examples of technology in use. They are not affiliated with PixyDelta.
Find your starting point.
Work through a practical problem with a working engineer and review the decisions behind your result.
Safikul IslamFull-stack developer · In-person sessions