Tutorials ADO.NET Core Tutorial

Enterprise Legacy Modernization — Capstone

Enterprise Legacy Modernization — Capstone: free step-by-step lesson with examples, common mistakes, and interview tips — part of ADO.NET Core Tutorial on Toolliyo Academy.

8 min read Updated 8/21/2026

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ADO.NET Core Tutorial · Lesson 100 of 100

Enterprise Legacy Modernization

Foundations ✓ → SQL & safety ✓ → Production ✓ → Projects

Projects · 4 — Portfolio builds · ~10 min · Module 10: Real-World Enterprise Projects

What is this?

Capstone: wrap legacy ShopNest procs with ADO.NET adapters, strangle one API path, add tests, metrics, and a cutover flag.

Why should you care?

Prove you can modernize without a big-bang rewrite.

See it live — copy this example

Use a .NET console or API project with SQL Server LocalDB. Run dotnet run after pasting.

public sealed class LegacyOrderAdapter : IOrderRepository
{
  public Task PlaceAsync(PlaceOrder cmd, CancellationToken ct) =>
    _exec.ProcAsync("usp_Legacy_PlaceOrder", cmd, ct);
}
// Feature flag: use LegacyOrderAdapter vs NewOrderRepository

What happened?

Characterization tests.
Adapter over usp_.
Flag traffic.
Metrics on both paths.

Practice next

Wrap legacy place proc.
Interface + flag.
Parity tests.
Shadow traffic compare.
Remove flag when 100% new.

Remember

Adapter strangler. Flags + metrics. Parity tests.

ShopNest modernization capstone

Legacy place-order strangler ships safely.

Outcome: Portfolio-ready ADO.NET modernization story.

Interview prep for this lesson

Practice these questions aloud after reading—each links to a full structured answer.

Junior PDF Detailed

What is ADO.NET?

Short answer: ADO.NET (Active Data Objects .NET) is a data access technology in the .NET framework that enables applications to interact with databases and other data sources. Explain a bit more It provides a set of clas…

Mid PDF Detailed

Memory Efficiency:?

Short answer: A DataReader is a forward-only, read-only cursor, meaning it streams data from the database and does not store the entire result set in memory. DataSet, on the other hand, loads the entire result set into m…

Mid PDF Detailed

Optimistic Concurrency Control:?

Short answer: Optimistic Concurrency assumes that conflicts will be rare and allows multiple users to read and modify data without locking it. Explain a bit more When updating data, you compare the current data in the da…

Mid PDF Detailed

Using ExecuteReader (for a single row, multiple columns):?

Short answer: SqlCommand command = new SqlCommand("SELECT CustomerName, ContactName FROM Customers WHERE CustomerID = @CustomerID", connection); command.Parameters.AddWithValue("@CustomerID", 1); conn…

Mid PDF Detailed

SqlCommand: Used for SQL Server databases. It represents a Transact-SQL?

Short answer: command or stored procedure. Example: SqlCommand command = new SqlCommand("SELECT * FROM Customers", connection); Example code command or stored procedure. Example: SqlCommand command = new SqlCom…

All course Q&A Practice exams

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