Claude Opus vs Sonnet for a Solo Developer

Start with one real task and a spending limit

Choosing between Claude Opus and Sonnet is easier when you stop asking which model is best overall. For a solo developer, the useful question is which model can finish the next task reliably at an acceptable total cost. A small interface change and a difficult concurrency bug should not automatically receive the same treatment.

For this walkthrough, use Claude Sonnet 5.5 as your starting model and Claude Opus 5.5 as your escalation option. This is a budgeting strategy to test, not a claim that one model always handles a particular category better. Begin with a real task from your project, then set a spending limit you would be comfortable repeating throughout the week.

Give Sonnet a narrow, verifiable assignment

Suppose you are adding validation to a signup form. Before asking for changes, describe the expected behavior, relevant constraints, and how you will check the result. Explain what should happen with empty fields, invalid input, and a successful submission. Ask the model to identify assumptions rather than silently invent requirements.

Keep the first assignment small enough to review yourself. Request a proposed approach before a broad implementation if the surrounding code is unfamiliar. A concise explanation and a limited change are usually easier to evaluate than a sweeping rewrite, regardless of which model produced them.

Define success before generating an answer. For this task, success could mean that the agreed validation cases pass, existing behavior remains intact, and the change introduces no unnecessary dependency.

Check the result before requesting another attempt

Run the relevant tests and inspect the proposed changes. Do not treat a confident explanation as evidence that the implementation works. If a check fails, send back the actual failure and the expected behavior instead of asking the model to try again without new information.

Separate missing context from weak reasoning. If you forgot to mention a validation rule, supply it and continue with Sonnet. Switching models will not reliably fix an incomplete specification. If the same underlying mistake survives a well-informed correction, however, you have a concrete reason to reconsider the model.

Escalate a difficult decision rather than the whole session

Now imagine the task exposes a deeper issue: two parts of the application disagree about when an account becomes active. Instead of handing Opus the entire conversation and requesting a complete rewrite, prepare a compact handoff. Include the requirement, relevant evidence, failed approach, and unresolved question.

Ask Opus to analyze that specific disagreement and compare plausible fixes against your constraints. You are testing whether a different model produces a more useful decision, not assuming that escalation guarantees correctness. Review its reasoning and validate any resulting changes with the same discipline you used earlier.

If the difficult question is resolved, return routine follow-up work to Sonnet. Escalation can be a single consultation rather than a permanent upgrade for every remaining request.

Compare the cost of finishing, not just answering

A cheaper request is not necessarily a cheaper completed task. Count retries, repeated context, and your own review time. Equally, a more expensive answer is not automatically worthwhile because it sounds more thorough. Record whether it actually helped you reach a verified result.

MyRelay gives one person one key and one pay-as-you-go budget across supported models. Its per-request token and cost visibility helps you compare the initial attempt, correction, and escalation instead of guessing from answer length. Create a MyRelay account if you want to track this workflow against one personal budget.

Turn a week of results into your default routine

After several ordinary work sessions, review which tasks finished without escalation and which benefited from it. Keep a simple record of task type, verified outcome, total spend, and approximate review time. Avoid drawing a broad conclusion from one unusually good or bad response.

Your default can remain simple: start narrowly with Sonnet, provide evidence when correcting it, and consult Opus when a specific unresolved problem justifies the extra spend. Keep checking the results. The aim is not to use the strongest-sounding option all day, but to build a repeatable workflow that protects both your attention and your budget.