Fractional CTO for GymStreak: shipping AI features at startup pace

The problem

GymStreak had real traction: an AI coach that builds personalised workout plans, with users who loved it. But the founders were carrying the whole technical side themselves. AI generation calls timed out under load and sometimes returned empty plans. There was no paywall, no trial logic, and no server-side receipt validation — which meant no dependable revenue.

Hiring a full-time CTO made no sense at their stage. What they needed was senior ownership of the tech, a few days a week, with AI-accelerated delivery behind it.

What we did

We stepped in as their fractional CTO. First we stabilised: the AI generation path got retries, fallbacks, response validation, and monitoring, so a plan request never comes back empty. Then we monetised: a subscription paywall with trial logic through RevenueCat and Stripe, with receipts validated server-side so revenue numbers are real.

Beyond the code, we set up the operating rhythm — a prioritised roadmap the founders control, weekly releases, and error monitoring with alerts that reach us before users complain.

• Hardened AI generation pipeline — retries, validation, fallbacks, monitoring
• Subscription paywall with trial logic and server receipt validation
• Release pipeline with staged rollouts and rollback
• Weekly roadmap call — 30 minutes, founder-led priorities
• Error and cost monitoring across the AI stack

The outcome

Subscriptions went live and stayed live. The AI pipeline now completes 99.9% of generation requests. The founders plan features against a weekly release cadence instead of hoping the next deploy holds — and they spend their time on growth, content, and users, not on debugging the backend at midnight.