Challenge
A fast-growing B2B SaaS company had outgrown its original billing setup — a mix of manual Stripe charges, spreadsheets and hardcoded plan limits. As the account base scaled, revenue leakage from missed upgrades, incorrect proration and failed retries became a serious problem. The engineering team needed a reliable billing engine that could grow with the product.
Approach
We began with a two-week audit of existing charge logic, Stripe webhook coverage and failure modes. Rather than rebuild from scratch, we designed a thin billing service layer that wrapped Stripe’s APIs, applied business rules (proration, seat-based billing, trial extensions) in one place, and exposed a clean internal API to the rest of the product.
What We Built
- Billing service with idempotent charge logic, retry handling and audit log
- Plan management UI for admins to create and modify tiers without code changes
- Usage metering pipeline that streams feature events and aggregates them per billing period
- Webhook processing for Stripe events with at-least-once delivery guarantees
- Migration scripts that moved 3,000+ existing accounts to the new structure with zero downtime
- Customer portal for self-service plan upgrades, invoice downloads and payment method changes
Outcome
Revenue leakage dropped significantly in the first quarter after launch. The support queue for billing questions fell sharply as customers could resolve issues themselves. The engineering team gained confidence to launch new pricing experiments because the billing layer was now a predictable, well-tested service rather than scattered logic.
All figures are illustrative of typical project outcomes. Exact results vary by client context.