AI Is Changing What 'Correct Software' Means

A developer argues that AI-generated code is breaking the traditional definition of correct software, where green CI pipelines and passing unit tests no longer guarantee semantic correctness. The developer proposes shifting from output equality assertions to system invariants and architectural fitness functions, and demonstrates a verification pipeline using NetArchTest and Semantic Kernel to enforce runtime guardrails on AI-generated code.

Software engineers used to define a "Correct software" via a simple deterministic binary an Expected Output . All Test are passed, but this is collapsing, a green CI pipeline no longer guarantees correct software, with AI-generated code that's look syntactically perfect and test-compliant yet they are semantically wrong in a ways that appears in productions. The bottleneck in software engineering is no longer writing code, it is verifying it execution intent Traditional software used to relies on deterministic assertions. We write code with known paths, control inputs, and verify exact results: Fact public void CalculateDiscount StandardUser ReturnsTenPercent { var calculator = new DiscountCalculator ; var result = calculator.GetDiscount UserType.Standard, orderTotal: 100 ; Assert.Equal 10, result ; } This works well because we write the logics and most bugs comes from missed edge cases or small mistakes. But with AI-generated codes, it follows a patterns based on trained context and user prompt. An agent will write code that pass 100% of our unit tests but silently violation non-functional, implicit system boundaries: So we got a syntactically valid and test passing code but architecturally incorrect. AI agents are exceptionally good at writing tests for the very code they just generated. If an agent writes a flawed implementation, it generates an equally flawed, matching assertion suite. When tests mirror the assumptions of the generation engine, unit tests become a confirmation bias machine. To govern AI-generated code, we must shift our definition of correctness from Output Equality Assert.Equal to System Invariants Constraint Validation at Execution Runtime . In an AI-native engineering workflow, correctness is defined by bounded runtime guardrails and architectural fitness functions . Instead of testing whether a function returned 10 , a verification engine continuously enforces structural constraints across the entire codebase execution model. Using this we are not just checking test results we are enforcing rules at runtime and checking that the system design stays valid. Let's build a practical implementation of an architectural verification pipeline. Instead of trusting AI-generated tests we will enforce rules that our system must always follow: using NetArchTest.Rules; using Xunit; public class ArchitectureVerificationTests { Fact public void DomainEntities MustBeImmutable AndNeverBypassedByAgents { // Enforce that AI-generated code cannot introduce mutable state into the Core Domain var result = Types.InCurrentDomain .That .ResideInNamespace "OrderSystem.Domain" .Should .BeImmutable .GetResult ; Assert.True result.IsSuccessful, "AI generated mutable entities in the domain layer " ; } Fact public void Handlers MustEnforceIdempotencyDecorator { // Ensure every generated Command Handler implements IIdempotentCommand var result = Types.InCurrentDomain .That .HaveNameEndingWith "CommandHandler" .Should .ImplementInterface typeof IIdempotentCommand .GetResult ; Assert.True result.IsSuccessful, "AI generated a command handler lacking explicit idempotency execution " ; } } For AI agent workflows running in production or ambient background tasks when it tries to change code or data, we validate its intent before allowing it so we ensure: using Microsoft.SemanticKernel; using Microsoft.Extensions.Logging; public record ExecutionIntent string TaskDescription, string TargetNamespace, string ProposedDiff ; public record VerificationResult bool IsValid, string StructuralDivergenceReason ; public class AgentVerificationEngine { private readonly Kernel kernel; private readonly ILogger<AgentVerificationEngine logger; public AgentVerificationEngine Kernel kernel, ILogger<AgentVerificationEngine logger { kernel = kernel; logger = logger; } public async Task<VerificationResult VerifyAgentActionAsync ExecutionIntent intent { // Define hard system invariants that the LLM engine cannot negotiate var verificationPrompt = """ You are an Architectural Verification Engine. Evaluate the proposed code change against the system invariants: SYSTEM INVARIANTS: 1. No direct database access outside Infrastructure/Repositories. 2. Memory allocations on critical paths must avoid heap overhead no boxing, use ReadOnlySpan<T where applicable . 3. All external state modifications MUST emit an IntegrationEvent. PROPOSED CHANGE: Target: {{$target}} Diff: {{$diff}} Respond ONLY in JSON format: {"is valid": true|false, "reason": "Detailed failure justification"} """; var arguments = new KernelArguments { "target" = intent.TargetNamespace, "diff" = intent.ProposedDiff }; var result = await kernel.InvokePromptAsync verificationPrompt, arguments ; var responseJson = result.GetValue<string ; // System parses verification evaluation deterministically return System.Text.Json.JsonSerializer.Deserialize<VerificationResult responseJson ; } } Deploy this verification process directly inside your Azure DevOps Pipeline or GitHub Actions Engine alongside Azure Container Apps for isolation: Moving to an invariant-driven verification architecture introduces real engineering trade-offs: AI is not removing the need for software engineering — it is raising the level of abstraction. When writing code becomes frictionless, the primary value of a senior engineer shifts from syntax authoring to system boundary definition . Stop relying solely on traditional unit tests to validate AI-generated code. Build verification engines that enforce immutable architecture invariants, audit non-deterministic outputs, and protect runtime stability. Software correctness is no longer about passing unit tests. It is about proving your system cannot violate its core invariants. How are you adapting your CI/CD pipelines to handle AI-generated code? Are you relying on static unit testing, or building verification boundaries? Drop your thoughts in the comments below