Give the architecture discussion a real starting line
Software architecture is the set of important choices about how an application fits together: where data lives, which component does each job, and what happens when something fails. You do not need a complicated diagram to start. You need a concrete problem and a few honest constraints.
Imagine you are building an application that accepts uploaded documents and generates reports. Your first architecture question is simple: should the application generate each report during the upload request, or hand that work to a background worker?
Claude Opus 5.5 and GPT-6 Astra can join this discussion as proposal writers and reviewers. Treat their answers as suggestions to investigate, not approvals to ship.
Write one brief before asking either model
Both models need the same starting information. Otherwise, you may mistake different assumptions for different architectural insights. Prepare a short brief that describes the user journey, your existing tools, and the limits your team actually faces.
- User journey: A person uploads a document, waits for processing, and downloads a report.
- Existing system: One web application and one relational database.
- Team constraint: Two developers will build and maintain the service.
- Failure concern: Processing may fail, and users must not lose their uploads.
- Unknowns: Typical document size, processing duration, and demand during busy periods.
Keep unknowns visible. Asking a model to fill them silently can produce a confident design for an application you are not building.
Assign a proposer and a skeptical reviewer
Give Claude Opus 5.5 the proposer role for the first round. This is a discussion structure, not a claim that one model is inherently better at architecture.
Starter prompt: “Using this brief, propose the smallest workable architecture. Describe the upload flow, data storage, processing steps, and failure handling. Separate facts from assumptions. Explain what would make your recommendation change.”
Then give GPT-6 Astra the original brief and the proposal. Ask it to review the design rather than produce an unrelated replacement.
Review prompt: “Review this proposal against the brief. Identify missing assumptions, unnecessary components, and failure cases. For each concern, suggest a concrete check or a simpler alternative. Do not invent requirements.”
You can reverse the roles in a later round. The useful mechanism is independent scrutiny, not a permanent hierarchy between models.
Follow one uploaded document through failure
Architecture becomes easier to understand when you trace one request. If the proposal includes a queue, think of it as a waiting list of jobs. A worker takes a job from that list and performs the processing outside the upload request.
Ask both models what happens if the worker stops halfway through. Can the job run again safely? Could the user receive two reports? What status will the application display?
This introduces idempotency: designing an operation so that repeating it does not create unwanted duplicate effects. For this application, a stable job identifier and a check for an existing result might help. The exact mechanism needs validation in your implementation.
A useful answer names the stored state, the retry behavior, and the recovery path. “Make it resilient” is not enough.
Keep the discussion affordable and reproducible
SwiftRelay is a practical option for bringing both models into this workflow through one pay-as-you-go relay. It works with Claude Code, Codex, Gemini CLI, and OpenAI-compatible SDKs, with billing per token.
Sign up for SwiftRelay to try the workflow with the small gift credit available to new accounts. Keep the shared brief in a local file, send only relevant context, and save each proposal and review. Remove secrets and sensitive customer information before sending material to any model.
Finish with a decision you can test
Do not end the meeting when the models agree. End it with a short decision record: the chosen design, its rationale, rejected alternatives, remaining unknowns, and a condition for revisiting the choice.
For the document application, the next step might be a small background-processing prototype with a deliberately interrupted job. Verify that processing can resume without duplicate results and that the user sees an accurate status. That test turns an appealing architecture discussion into evidence your team can use.