Multi-Tenant SaaS Billing & Usage

Usage metering, tiered subscriptions, and provider-agnostic billing for a multi-tenant SaaS, accurate to the event and reconciled automatically.

99.99%

Billing accuracy

100%

Event-accurate metering

0

Manual reconciliations

The challenge

A SaaS product had outgrown flat pricing; usage-based billing was a spreadsheet nightmare: 200+ manual invoice adjustments per month, 5% revenue leakage from metering gaps, and 3-day close cycles. They needed event-accurate metering, tiered plans, and self-reconciling billing.

The solution

We modeled usage as an append-only event stream metered in real time, layered tiered subscription logic on top, and abstracted billing behind an idempotent gateway so charges and credits reconcile automatically.

Architecture

01

Usage is an append-only event stream on Kafka; invoices are a re-derivable projection, never hand-edited.

02

Tiered subscription and proration logic is modeled explicitly, not encoded in ad-hoc queries.

03

The billing gateway is idempotent so retries and webhooks can never double-charge.

Industry

SaaS


Results

Billing is accurate to the event, usage is metered in real time per tenant, and monthly manual reconciliation was eliminated entirely.


Tech stack

TypeScript
Node.js
PostgreSQL
Redis
Kafka
Stripe

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