Experienced Macos Swift/Swiftui Developer for Ongoing Technical Support and Code Review

I'm a solo founder looking for an experienced macOS developer for ongoing technical support and code review on a native macOS application built with Swift and SwiftUI. This is not a full-time or part-time employment position, but rather an ongoing engagement for senior judgment and expertise.

The application is a music practice tool, and the technical areas involved include:
- Swift / SwiftUI with AppKit interop
- AVFoundation and Core Audio for real-time playback, time-stretching, multi-track mixing, and handling audio device changes
- PDFKit and WKWebView integration
- Familiarity with Xcode, code signing, notarization, and Sparkle updates

The primary need is for a 'second set of eyes' to review code, catch potential issues, and assist with debugging complex problems. The work is expected to be roughly 3-8 hours per week, with variations.

Key responsibilities will include:
1. Performing code reviews on changes before they ship, focusing on correctness, architectural integrity, and adherence to macOS conventions.
2. Providing expert opinions and guidance on technical approaches, especially for critical components within the audio path.
3. Assisting with debugging specific problems when I get stuck.
4. Undertaking occasional focused implementation tasks as needed.

It is important to note that this role is for senior judgment and support, not for independent feature development. The ideal candidate will apply their expertise to work that is already in progress.

Required qualifications:
- Proven experience having shipped at least one real macOS application (not iOS only), demonstrating a deep understanding of macOS-specific development challenges.
- Ability to comfortably read and understand a large existing codebase.
- A direct and clear communication style, providing constructive feedback.
- Availability for asynchronous reviews with a reasonable turnaround time.

Nice-to-have skills include audio programming experience and familiarity with working alongside AI-generated code.

The engagement will be paid hourly, on an ongoing basis. I'd like to start with one paid review of a real code change, so we both find out whether it works before either of us commits to more.

In your proposal, please tell me about one macOS-specific bug you've fixed and how you found it. I'll read those first.