Claude can be your on‑demand coding companion—whether you need a quick code review, a refactor plan, or help debugging obscure bugs. Below are 30 ready‑to‑paste prompts, grouped by typical dev tasks. Replace the [PLACEHOLDERS] with your own file names, snippets, or error messages, then copy the prompt and feed it to Claude for instant, actionable output.
You are a senior software engineer. Review the following [LANGUAGE] file for:
- bugs or logical errors
- security concerns
- performance bottlenecks
- adherence to best practices and style guide
Provide a markdown report with line numbers, issue description, severity (low/med/high), and a suggested fix.When you have a whole source file and need a concise audit.
Summarize the changes in this pull request:
[PASTE DIFF OR GITHUB PR URL]
Highlight:
- New features
- Breaking changes
- Potential regressions
Suggest a short reviewer comment for each major change.Great for busy reviewers who need a quick overview.
Scan the following code for security issues (SQL injection, XSS, insecure deserialization, etc.):
[CODE SNIPPET]
List each vulnerability, explain the risk, and give a code‑level fix.Use after adding user‑input handling or third‑party libraries.
Refactor this block into a reusable function and show the new function definition plus the updated calling code:
[CODE BLOCK]
Use clear naming and add a docstring describing inputs, outputs, and side effects.When you notice duplicated logic in a module.
Improve the time/space complexity of this algorithm while keeping the same output:
[ALGORITHM CODE]
Explain the new complexity and why it’s better.Ideal for loops that run O(n²) or higher.
Modernize this legacy [LANGUAGE] snippet (e.g., replace callbacks with async/await, use f‑strings, etc.):
[OLD CODE]
Show the updated code and a brief change log.Use when migrating a codebase to newer language versions.
Explain this stack trace and suggest the most probable cause:
[STACK TRACE]
Provide a step‑by‑step debugging plan.Paste the exact console output for fastest results.
Given the following description of a bug, write a minimal reproducible example in [LANGUAGE]:
[BUG DESCRIPTION]
Include comments indicating where the failure occurs.Great for creating test cases before filing an issue.
Generate robust try/except (or try/catch) blocks for this function, logging errors with stack trace and returning a default value:
[FUNCTION CODE]
Assume we use the standard logging library.Add when adding resilience to critical paths.
Write a Markdown API reference for this function, including:
- Signature
- Parameter table with types and descriptions
- Return type and description
- Example usage
- Edge‑case notes
[FUNCTION CODE]Use after completing a new public method.
Generate a changelog entry for version [X.Y.Z] based on these commit messages:
[COMMIT LIST]
Group changes into Added, Fixed, Changed, and Deprecated.Helps keep release notes tidy.
Create a concise design doc (max 300 words) for implementing [FEATURE] in a microservice architecture.
Include:
- High‑level flow diagram (ASCII)
- Key interfaces
- Data storage choice
- Failure handlingUseful for sprint planning or stakeholder reviews.
Write a set of unit tests in [TEST FRAMEWORK] for the following function:
[FUNCTION CODE]
Cover normal cases, edge cases, and error paths. Use descriptive test names.Kick‑start test coverage for new modules.
Provide a mocking plan for this integration test scenario:
- External API: https://api.example.com/v1
- Database: PostgreSQL
Show code snippets using [MOCK LIBRARY] to stub network calls and DB queries.When external dependencies make tests flaky.
Write a GitHub Actions step that:
- Lints the code with [LINTER]
- Runs unit tests with coverage report
- Fails on coverage < 80%
Provide the YAML snippet.Add to .github/workflows/ci.yml for immediate enforcement.
[PLACEHOLDER] tags consistently; Claude treats them as variables you’ll replace.