Fractional CTO — consumer music app (iOS + Node/TS + React)

JoinJam is a consumer music collaboration app (iOS primary + web Studio / Radio / Jam Room embeds + Node/TypeScript Fastify API, Postgres on Railway, Cloudflare R2, Sentry, Stripe + Apple IAP).

We’re hiring a fractional CTO / technical lead — not a rewrite hire and not a junior feature factory.

About the role (10–20 hrs/wk, start ~10)
• Own reliability, security, release discipline, and architecture judgment
• Sev-1 ownership with the founder; Sentry triage; clear “done” bars
• Review standards for Cursor-assisted shipping (billing, auth, migrations, and media need human review)
• Harden auth / payments / media ACL / admin surface; investor technical diligence readiness
• Help set TestFlight + deploy cadence; coach contractor review

Must-haves
• Full-stack product judgment: Node/TS APIs + React + mobile (iOS strongly preferred)
• Prod ops (Postgres, PaaS like Railway), observability, auth/payments literacy
• Media systems intuition (uploads, object storage, WKWebView embeds)
• Clear communication with a non-technical CEO

Not looking for
• Greenfield rewrites or “replace Cursor”
• Pure ticket-taker full-stack only
• Primary Android ownership before the iOS launch path is solid

Engagement
Ongoing fractional / contract retainer with a 30–90 day trust ramp before broader production access. NDA + IP assignment required. Cash-first; equity may be discussed after proven fit (counsel-structured).

Apply with a short note covering:
1) First hardening pass you’d run on our API/auth/payments surface
2) How you’d triage a Sev-1 across iOS + API + web embed
3) Weekly availability + rate or monthly retainer ask for ~10 hrs/wk