From Bug Report to Fix in 15 Minutes: The AI Debugging Revolution

It was a regular Tuesday morning. I was sipping my first coffee, settling into the rhythm of the day while working on ShopFlow—our flagship B2B e-commerce platform. ShopFlow is a complex beast; it manages intricate product catalogs, tiered pricing structures, and deep supplier integrations for thousands of clients. Then, the inevitable ping on Microsoft Teams arrived.

"Hey, some of our pricing plans are missing from the Pricing Manager screen," a colleague from the support team noted. "The data is definitely in the database—I checked the SQL tables myself. Can you look into why the UI isn't showing them?"

In the "old days" (which, let's be honest, was only about 18 months ago), this would have triggered a familiar, grueling ritual. I would have opened SQL Server Management Studio (SSMS), spent 15 minutes writing exploratory queries, grepped through a massive C# codebase to find the right service, read through layers of abstraction, made a few guesses, attached a debugger, and repeated the cycle. It was easily a 2-hour minimum affair, mostly spent on the "tax" of switching between windows and mental contexts.

This time, however, I had a different toolkit. I stayed entirely within my IDE, leveraging the power of the Model Context Protocol (MCP) and an AI coding assistant. The result? The bug was identified, documented, fixed, and verified in exactly 15 minutes.

The Modern Developer's Arsenal

Before we dive into the play-by-play, let's look at the stack that made this possible. The magic isn't in any single tool; it's in how they compose together into a continuous workflow with zero context switching.

• AI Coding Assistant (Cursor): My primary interface for code analysis, semantic search, and implementation.
• Database MCP (dbhub): This allows the AI to have direct, read-only SQL access to my database. I can ask questions about the data without leaving the chat.
• Azure DevOps MCP: A tool that lets the AI read, create, and update work items directly via the Azure DevOps API.
• Swagger UI: For final API verification.

Step 1: Semantic Analysis and Root Cause (3 minutes)

I didn't start by searching for filenames. I simply described the symptom to Cursor: "Users are reporting missing pricing plans in the Manager screen. Find the backend code that fetches these plans."

Within seconds, the AI performed a semantic search across the repository and located the relevant handler in GetPricingPlansQuery.cs. It pointed me directly to this LINQ query:

var plans = await _dbContext.PricingPlans
    .Where(p => p.StartDate <= now && p.EndDate >= now && p.IsActive)
    .OrderBy(p => p.DisplayOrder)
    .Select(p => new PlanDto { Id = p.Id, Name = p.Name })
    .ToListAsync(cancellationToken);

The AI didn't just find the code; it immediately flagged a logical vulnerability: "The condition p.EndDate >= now will evaluate to false when EndDate is NULL. In SQL, any comparison with NULL returns UNKNOWN, which filters the row out. If NULL represents a plan that never expires, these records are being hidden incorrectly."

Step 2: Verification via Database MCP (2 minutes)

I had a hypothesis, but I needed data. Instead of Alt-Tabbing to SSMS, I asked the AI (via the Database MCP): "Check the PricingPlans table. Are there active plans with NULL EndDates?"

The AI generated and executed the query internally:

SELECT Name, StartDate, EndDate, IsActive 
FROM PricingPlans 
WHERE IsActive = 1;

The results came back instantly in the chat sidebar:

• Basic Monthly: EndDate = NULL
• Pro Annual: EndDate = 2027-12-31
• Enterprise: EndDate = NULL

The data confirmed it: 75% of our plans had no expiration date (NULL), and our code was treating them as "expired."

Step 3: Automated Documentation (2 minutes)

Professional engineering requires a paper trail. Using the Azure DevOps MCP, I commanded the AI: "Create a bug ticket in our backlog. Title it 'NULL EndDate Pricing Bug'. Explain the cause and the fix."

The AI drafted a comprehensive ticket including:

• Description: Logical failure in GetPricingPlansQuery where NULL values in the EndDate column result in records being filtered out.
• Acceptance Criteria: Plans with NULL EndDate must appear; expired plans must remain hidden.

I clicked "Confirm," and the work item was live in Azure DevOps. No browser opened, no login required.

Step 4: The One-Line Fix (1 minute)

The fix was trivial, but the AI's ability to apply it safely was the key. I accepted the suggested change:

// Before
.Where(p => p.StartDate <= now && p.EndDate >= now && p.IsActive)

// After
.Where(p => p.StartDate <= now && (p.EndDate == null || p.EndDate >= now) && p.IsActive)

Step 5: Debugging the "Bonus" Issue (5 minutes)

I tried to verify the fix via Swagger, but I hit a 403 Forbidden. My test user didn't have the PRICING_PLAN:READ permission. Usually, I'd dig through the AuthorizationScope tables manually. Instead, I asked the AI: "My user ID is 'dev-user-01'. Why am I getting a 403 on this endpoint? Query the auth tables."

The AI navigated the relationship between Users, UserGroups, and AuthorizationScopes using the MCP. It discovered the permission didn't exist for my group and provided the fix:

INSERT INTO UserGroupAuthorizationScope (GroupId, Scope)
VALUES ('admin-group-id', 'PRICING_PLAN:READ');

I executed this via the tool, and the API immediately returned the correct, unfiltered data.

The Economics of Productivity: 15 vs. 80 Minutes

Let's break down the traditional vs. AI-enhanced time consumption:

The 5x speedup didn't come from the AI writing the code—the code change was simple. The speedup came from the elimination of Cognitive Load. Every time you switch from C# to SQL, or from your IDE to a browser, your brain pays a "context switching tax." AI with MCP integrations keeps you in the "Flow State."

Strategic Insights: Why MCP is a Game Changer

If you're a Tech Lead or Architect, the lesson here isn't just "use AI." It's "integrate your context." Here are three key takeaways:

1. Context is King, but Integrated Context is God

An LLM that can only see your code is like a blindfolded chef. It knows the recipe but can't see the ingredients. By providing the AI with access to the Schema (Database MCP) and the Business Requirements (Azure DevOps MCP), you give it the "eyes" it needs to provide truly accurate solutions.

2. Security by Design

When implementing these tools, use Read-Only permissions for the AI's database connection in production, or limit it to local/staging environments. In my case, using a local dev-db bridge ensured that the AI couldn't accidentally drop a production table while trying to "fix" a bug.

3. The Death of the "Grep" Workflow

We are moving away from lexical search (searching for exact strings) toward semantic intent. The AI understands that "missing pricing plans" relates to PricingPlans, Active status, and DateRanges, even if those exact words aren't in the bug report.

Conclusion

The future of software engineering isn't about AI replacing developers; it's about AI removing the friction between intent and execution. The 15-minute fix I described wasn't a miracle—it was the result of a perfectly integrated environment where the tools understood the code, the data, and the process simultaneously.

If you haven't explored the Model Context Protocol (MCP) yet, start today. Whether it's connecting your database, your logs, or your task manager, every bridge you build reduces the distance between a bug report and a satisfied user.