Revello | Guilherme Fath | Guilherme Fath

Overview

Revello gives gym owners a clearer view of members, billing, churn risk and WhatsApp follow-up without forcing them to manage everything manually.

Business problem

Gym managers spend too much time chasing payments, checking inactive members and coordinating WhatsApp messages by hand. By the time churn becomes obvious, the member is usually already gone.

Product approach

The product joins billing, member activity and messaging so routine follow-ups can be automated while sensitive actions stay reviewable and logged.

My role

I worked on product architecture, domain modeling, web interfaces, APIs, tests and integrations for the gym operations model.

Key capabilities

member management

plans

billing

PIX, boleto and card payment paths

payment webhooks

check-ins

attendance monitoring

churn-risk detection

inactive-member recovery

WhatsApp agents

scheduling and reminders

MRR and retention indicators

multi-location management

operational logs

human approval for sensitive actions

API and webhooks

Architecture

Revello system view

Technical decisions

TypeScript monorepo for shared product language.

Domain packages for reusable gym operations concepts.

Payment events handled through explicit billing states.

Human approval on sensitive automated actions.

Operational logs for auditability.

Vitest coverage around business-critical logic.

Challenges and trade-offs

Translating gym operations into reusable domain models.

Handling billing events safely.

Detecting operational risk signals.

Combining automation with human approval.

Maintaining auditability.

Supporting multiple units.

Production and operations

The product is structured for beta and production use with observability, tests and controlled automation paths.

Stack

Next.jsNestJSTypeScriptPostgreSQLPrismaVitest

What I learned

Vertical SaaS works best when generic software patterns are shaped around the language and edge cases of the operation.

Next project

Imob Agents

A vertical SaaS product that uses WhatsApp conversations to update property portfolios, structure owner replies and create prioritized tasks for agents.