Give each model a job before your first coding lap
You do not need to choose one coding assistant for every task. A practical starting point is to give Claude Sonnet 5.5 the clearly defined edits and bring Claude Opus 5.5 into decisions that need more investigation. Treat this as a workflow to try, not a guarantee that one model always produces better code.
The useful distinction is clear work versus uncertain work. Changing a label has a visible finish line. Deciding where authentication belongs requires understanding the application. Match your request to that uncertainty, then judge the result through inspection and tests.
Start Claude Sonnet 5.5 with one bounded change
Use Claude Sonnet 5.5 as your starting point when you can explain the desired behavior, identify the relevant files, and describe how to check success. Keeping the assignment small makes its output easier for a newcomer to review.
- Add validation to an existing form using the project's current patterns.
- Write tests for a function whose expected behavior is already documented.
- Update an error message without changing the underlying logic.
- Refactor a repeated helper while preserving its public interface.
A useful prompt is: “In the checkout form, reject an empty postal code. Follow the existing validation style, add a test, and avoid unrelated changes. Explain which files you changed.” That gives the assistant a target, boundaries, and a way to demonstrate completion.
Bring Claude Opus 5.5 into unclear decisions
Try Claude Opus 5.5 when you are not yet sure what should change. Examples include tracing a bug across several modules, examining a proposed database migration, or choosing between two implementation approaches. Ask for analysis before authorizing edits.
For example: “An order sometimes gets saved twice. Trace the request path and identify possible causes. Separate evidence from guesses, suggest a minimal fix, and explain which tests would confirm it. Do not edit files yet.”
This separates diagnosis from implementation. You get a chance to question the reasoning before a plausible explanation becomes a large patch. If the assistant lacks logs, configuration, or relevant files, ask it to name those gaps rather than fill them with assumptions.
Hand over a small plan, not an entire conversation
Once the investigation produces a clear plan, you can give the implementation to Claude Sonnet 5.5. The handoff should contain the goal, relevant files, constraints, and acceptance checks. Do not assume that switching models automatically carries over every detail; check what your tool actually preserves.
- Goal: Prevent duplicate order creation on repeated requests.
- Scope: Change the order handler and its tests only.
- Constraint: Keep the existing response format.
- Checks: A repeated request creates one order; normal checkout still succeeds.
If implementation reveals a missing design decision, pause and revisit the plan. Repeating the same vague request with a different model rarely fixes missing requirements.
Check the patch before choosing another model
Read the diff, meaning the list of changed lines, and run the relevant tests. Ask the assistant to report which checks it actually ran and which it only recommends. A confident explanation is not evidence that a command succeeded.
Use a second-model review selectively for changes involving permissions, payments, data deletion, or unfamiliar code. Ask for concrete failure cases rather than general approval. Both models can miss the same problem, so human review and automated checks remain necessary.
Run this coding split through SwiftRelay
SwiftRelay is a practical option for trying this workflow through one pay-as-you-go relay. It works with Claude Code and OpenAI-compatible SDKs, with billing per token. Check the available model identifiers and your tool's configuration instructions before switching between the two models.
Sign up for SwiftRelay to try this split with the small gift credit available to new accounts. Start with one bounded task, inspect the result, and bring in deeper investigation only when the work calls for it.