MylarPro — Multi-Tenant SaaS for Brazilian Real-Estate Operations

Overview

MylarPro is a complete multi-tenant SaaS for the Brazilian real-estate market, built so agencies can manage the full lifecycle of contracts, billing, payouts to owners, and customer relationships. The monorepo bundles nine independent applications—backend, four web frontends, mobile apps, a public catalog, and marketing pages—all integrated via API and backed by a single PostgreSQL database with 100+ Prisma models.

More than a CRM, it is a financial-operations system that automates dunning, boleto/PIX issuance, commission math, owner payouts, DIMOB (Brazilian rental-income reporting), and bank reconciliation—with accounting discipline aligned to how the local market actually works.

Technical architecture & responsibilities

• Backend (NestJS + Prisma): Clean Architecture with strict separation of domain, application, and infrastructure. Injected use cases, abstract repositories, mappers between domain entities and persistence, and Either-based error flows.
• Multi-tenancy: Every query scoped by organizationId with ownership checks on each operation. Isolation enforced at the application layer.
• Frontends (Next.js): Four App Router apps on React 19 and Tailwind v4. Shared module layout (services, queries, models, components) and a consistent stack: React Query, Zod, react-hook-form, shadcn/ui.
• Mobile (Expo): Broker app in React Native with calendar, visits, clients, contracts, and profile—11 endpoints dedicated to the mobile client.
• Infrastructure: Bull + Redis queues (seven queues: payment, notification, WhatsApp, lead scoring, invoice processing, and more), Gotenberg for PDFs, Cloudflare R2 for files, multi-stage Docker deploys via GitHub Actions.

Stack

• Backend: NestJS 11, Prisma 7, PostgreSQL 17, Redis, Bull, TypeScript
• Frontends: Next.js 15/16, React 19, Tailwind CSS v4, shadcn/ui, React Query, Zod, Zustand
• Mobile: Expo, React Native, TypeScript
• Integrations: Stripe, ASAAS, SendGrid, Twilio, Evolution API (WhatsApp), Cloudflare R2
• Document generation: Gotenberg (production-grade PDFs)
• Observability: Sentry (frontend), Datadog APM + Pino (backend)
• Deploy: Multi-stage Docker, GHCR, GitHub Actions, SSH deploy

Implemented features

• Billing groups & invoices: Recurring rent groups, one-off invoices, annual index adjustments (IGP-M, IPCA, INPC, FIXED) via cron.
• Fees & commissions: Automatic admin fee and broker commission per paid invoice, with hierarchy contract → group → override.
• Fines, interest & partial payments: Fixed fine + proportional daily interest on arrears, partial payments with PARTIALLY_PAID status and full transaction history.
• Proof-of-payment workflow: Customer uploads proof in the portal → PENDING_APPROVAL → admin approves/rejects with a full audit trail.
• Payouts & adjustments: Automatic payout to owners after payment, PDF statements via Gotenberg, manual adjustments to settle against future payouts.
• Visual dunning timeline: Fifteen configurable steps per organization, manual resend, and multi-channel delivery (email, WhatsApp, SMS).
• Debt agreements / installments: Consolidate invoices into agreements with discounts, installments, and IN_AGREEMENT status.
• Bank reconciliation: OFX 1.x + CSV parsers (BR/US), auto-matching by amount and date with tolerance, manual confirmation UI.
• DIMOB & income statements: Yearly aggregation per owner and property, PDF output for income-tax filing.
• Customer portal: CPF/CNPJ + OTP (email/WhatsApp), separate JWT, 13 routes for invoices, contracts, properties, payouts, tickets, and maintenance.
• Public SEO catalog: Listings with meta tags, analytics, embedded chat, and portal feeds (e.g. Imovelweb / XML).
• Broker mobile app: Profile module with 11 endpoints, document approval workflow, OTP for email change, validated PIX key picker.

Engineering highlights

• Architectural rigor: Clean Architecture without shortcuts—immutable entities via Entity.create(), abstract repositories, explicit mappers, and Either in 100% of use cases.
• Leak-proof multi-tenancy: organizationId validated on every operation, audited by default at the controller layer.
• Resilient processing: Bull queues with five retries and exponential backoff replaced fire-and-forget for critical paths (payments, boleto generation, notifications).
• Financial data quality: Custom validators (IsValidPixKey, CPF/CNPJ), soft delete on invoices and groups, full audit trail for partial payments.
• Performance & DX: Standardized Prettier + ESLint, absolute imports, 100+ documented Prisma models, ~100 use-case modules organized by feature.