The challenge
Boutique Pilates studios often run on a patchwork of spreadsheets, payment links, and messaging apps. Members can’t book cleanly; the studio can’t see who’s active, who’s overdue, or which classes fill. Flexii needed one system that matched how a small studio actually operates — with booking that scales as the roster grows, and access control that keeps member and staff data properly separated.
How we worked
We ran the engagement through our usual approach:
- Discover — map studio ops (classes, packages, instructor vs member roles) and the email touchpoints every booking and membership change generates.
- Strategy — choose a serverless-friendly stack early so the portal, data, and transactional email could scale without a rewrite.
- Build MVP — ship the member portal and studio booking flows on TanStack Start, Supabase, and Vercel.
- Scale — deepen booking management for Pilates schedules and harden RBAC with row-level security.
- Support — keep membership, booking, and notification paths evolving with the studio.
What we did
We built a subscription and booking platform purpose-fit for Flexii Studios in London Colney:
- Member portal — sign in, book sessions, and manage the account without calling the desk.
- Memberships & billing — recurring plans that reflect studio packages, not a one-size fitness SaaS template.
- Booking management for Pilates — class capacity, session schedules, and member bookings designed for how a boutique studio fills the room — not a mega-gym timetable.
- Transactional email via Resend — confirmation, reminder, and status emails for each process in the membership and booking lifecycle, so the studio isn’t the middleware in WhatsApp.
- Studio ops clarity — customers, sessions, and status in one place so the founder isn’t chasing spreadsheets.
Technical architecture
| Tier | Role | What we shipped |
|---|---|---|
| Presentation | Member & studio experience | TanStack Start app — portal, booking, and membership flows |
| Hosting | Edge delivery | Vercel — static and server routes that stay fast for members and staff |
| Data & auth | Durable state + access | Supabase — Postgres, auth, and RBAC enforced with secure RLS so members, instructors, and studio admins only see what their role allows |
| Process notifications | Resend — high-volume transactional mail for bookings, membership changes, and studio ops |
Security & access: We implemented RBAC with tightened row-level security on Supabase — role boundaries live in the database, not only in the UI. Booking and membership rows are gated so a member cannot read another member’s schedule, and studio staff get the ops views they need without over-exposing data.
Why this shape: TanStack Start kept the product as one coherent app on Vercel; Supabase gave auth and data that scale from day zero; Resend absorbed the volume of process emails a busy Pilates studio generates; RBAC + RLS made multi-role use safe as the studio grew.
What we did differently
We didn’t force a mega-gym feature set onto a Pilates studio. Scope stayed tight: book, belong, pay — plus the email and access model those jobs require — with a calm member experience that feels like Flexii, not a white-label booking widget.
The outcome
Flexii runs memberships and session booking through a dedicated portal — replacing the spreadsheet-and-DM workflow with software that matches the studio’s scale, with booking management and notifications that keep pace as classes fill.
Stack & scope
Product strategy, TanStack Start on Vercel, Supabase with RBAC and secure RLS, Resend transactional email, and Pilates-focused booking & membership ops — designed and built with Shola Digital.