When All Your Tests Pass But Nothing Works

Five hundred tasks. All passing.

You load the app. Blank page.

The orchestration trap

You broke the project into subtasks. Each subtask got its own agent. Each agent did its job. Tests passed. Coverage looked fine. The CI pipeline was green across the board.

Then you opened the browser.

Nothing. A blank page staring back at you. Five hundred tasks completed, and the application doesn't render.

"I had like 500 tasks passing but nothing was working like I couldn't see anything my page was just blank."

Guest, Roo Cast S01E02

This is the orchestration trap. Spec-driven development tools promise to parallelize work: break the project into pieces, assign each piece to an agent, let them run independently, merge the results. The theory is sound. The integration step is where it falls apart.

Why sub-agents don't talk to each other

The pattern is predictable once you see it. Each sub-agent works against its own spec. It writes code that satisfies its tests. It doesn't know what the other agents are building. It doesn't communicate about contracts, interfaces, or handoff points.

Agent A builds the auth module. Agent B builds the dashboard. Agent A exports a function called getUser(). Agent B expects a function called getCurrentUser(). Both agents pass their tests. The application crashes on load.

"I feel like this is the problem with orchestration workflows or tasks dividing something into smaller tasks and giving it to individual agents. I feel like the integration part that glues all of it together it's not good enough for now."

Guest, Roo Cast S01E02

The integration layer, the thing that glues the pieces together, is the weakest link in the chain. Individual task completion is easy to verify: run the test, check the output. Cross-task integration is harder to specify and harder to test in isolation.

The workaround: human checkpoints

Until orchestration tools get smarter about contracts and handoffs, the fix is manual verification at task boundaries.

Don't let 500 tasks run to completion before you check if the app loads. Insert checkpoints. After the first five tasks complete, verify the foundation. After the auth module ships, verify it integrates with the shell. After each major boundary, run the app.

"I think the solution to this might be to add some human in the middle you know when you're creating the plan when you're dividing all of these tasks add some verification points so the user can test like everything we have so far."

Guest, Roo Cast S01E02

This feels like a step backward. The whole point of parallelizing work was to remove the human bottleneck. But the alternative is worse: waiting until everything is "done" and discovering that nothing works.

The tradeoff

Checkpoints slow you down. They interrupt the parallel execution model. They require someone to actually load the app and click around.

But they catch integration failures early, when the fix is small. A mismatched interface after five tasks is a ten-minute fix. A mismatched interface after 500 tasks is an archaeology project.

The cost of verification is predictable. The cost of late-stage integration debugging is not.

Why this matters for your team

For a Series A - C team running spec-driven workflows on a new feature, this pattern hits hard. You kicked off the orchestrator on Friday. You expected to review a working PR on Monday. Instead, you're debugging why the app won't start.

The compounding effect is real. If one integration failure takes two hours to diagnose, and three boundaries failed silently, you've lost a day. That's a day you planned to spend on the next feature.

The shift: treat orchestration output as drafts, not finished work. Verify integration at boundaries. Keep the human in the loop where contracts meet.

How Roo Code closes the loop on integration failures

Roo Code addresses integration failures by keeping a human in the loop at every stage of the workflow. Unlike spec-driven orchestration tools that run hundreds of tasks before surfacing results, Roo Code closes the loop by running commands, observing outcomes, and iterating based on real feedback.

With BYOK (Bring Your Own Key), you control the model and the cost of each verification step. You can configure Roo Code to run your test suite, load the app, and report what it sees before moving to the next task. The agent doesn't just check if tests pass - it can verify that the application actually renders.

The key difference: Roo Code treats verification as part of the task, not something that happens after 500 tasks complete.

Orchestration approaches compared

The checkpoint question

When you break a project into parallel tasks, ask: where are the integration boundaries? Those are your verification points.

Don't wait for 500 green checkmarks. Check the app loads after five.