Excellent choice! Grails is ReportBurster's recommended stack for a reason — it gives you:

Consistency with ReportBurster's Groovy scripting
Fast development with convention over configuration
Built-in security (Spring Security integration)
REST API ready for ReportBurster integration

And Hermes on our team specializes in Grails portals — he'll be your implementation partner once we define the requirements.

Before We Build — Let's Define What You Need

I'd like to write a PRD with you for this billing portal. Here are the key questions:

Customer & Usage

  1. How many customers will use this portal? (10, 100, 1000+?)
  2. Do you already have customer data somewhere (CRM, database)? Or will this be the first system?

Billing Workflow

  1. One-time invoices or recurring subscriptions? (e.g., monthly bills)
  2. How are bills created today? (Manual process, another system, etc.)
  3. Payment methods: Stripe, PayPal, bank transfer, or need multiple options?

Portal Features (V1 — What's Essential?)

  1. What's the minimum viable portal?
    Login + view current bill + pay? Or need bill history + payment history from day one?
  2. Do customers need to download PDFs of their bills?

Technical

  1. Do you have ReportBurster Server (for automatic bill publishing) or just desktop version?
  2. Will the portal be internal-only (company network) or public-facing internet?

Once you answer these, I'll draft a Billing Portal PRD with clear scope (v1 vs. future features), user stories, data model recommendation — hand-off ready for Hermes.