Engineering & Software Development

Payments & Billing Engineer

Payment and billing systems are unforgiving of edge cases (a missed webhook, a failed dunning retry, an unreconciled subscription change) because every one of those failures touches actual money and actual customer trust. We build Stripe, Adyen, or Braintree integrations end to end: webhook processing that's actually idempotent, dunning logic for failed payments, and subscription-billing reconciliation that catches discrepancies before finance does. This is for products adding or fixing payment infrastructure where the cost of getting it wrong is a broken customer relationship or a revenue leak. You get a payment system tested against real failure scenarios, with reconciliation you can trust.

This is a capability we deliver for you as a service, not a role we’re hiring for.

How We’d Approach This

A clear, staged plan, not a black box

These are the service-specific steps inside our six-step process.

1
Map your billing model (one-time, subscription, usage-based) and the payment provider's specific edge cases.
2
Build the core payment and webhook flow, testing it against simulated failures like declined cards and retries.
3
Review the dunning logic and reconciliation reports with finance stakeholders before going live.
4
Launch the payment integration with reconciliation monitoring catching discrepancies automatically.

What You Get

Deliverables from this engagement

Production payment integration (Stripe/Adyen/Braintree)
Idempotent webhook processing tested against failure scenarios
Dunning and failed-payment recovery logic
Billing reconciliation reports for finance

Six Ways We Could Architect This

Different engagement, different build, pick the shape that fits

There’s more than one way to deliver on this service. Browse a few of the ways we’d structure the work, depending on your speed, budget, and integration needs.

Read all 6 architectures as text

Lean Fast-Start Architecture

Core Payment Integration

Checkout Form
Payment Provider SDK
Charge Creation API Call

Webhook Handling

Webhook Endpoint
Idempotency Key Check
Event Type Router

Billing Records

Payment Record Store
Subscription Status Table
Basic Dunning Email

Operations

Manual Reconciliation Spreadsheet
Finance Review
Support Escalation

Cloud-Native / Managed Services Architecture

Managed Payment Provider

Stripe Billing
Hosted Checkout Page
Provider Managed Vault

Managed Processing

Managed Webhook Queue
Serverless Webhook Handler
Managed Database for Ledger

Reconciliation Services

Automated Reconciliation Job
Finance Reporting Service
Tax Calculation Service

Operations

Monitoring and Alerting
Automated Backups
Finance Dashboard

Event-Driven & Automation-First Architecture

Payment Events

Charge Succeeded Event
Charge Failed Event
Subscription Renewed Event

Event Queue

Message Queue
Idempotent Event Consumer
Dead Letter Queue

Automated Workflows

Dunning Retry Workflow
Invoice Generation Workflow
Revenue Recognition Job

Notifications

Customer Payment Email
Finance Slack Alert
Failed Payment Recovery Flow

Enterprise-Grade & Compliance-Ready Architecture

Governance

SOC 2 Controls
Access Control for Payment Data
Change Approval Workflow

Security

PCI DSS Scoped Vault
Tokenization Service
Fraud Detection Engine

Redundancy

Multi Region Payment Processing
Ledger Database Replica
Automated Failover

Audit and Compliance

Immutable Audit Log
Reconciliation Compliance Report
External Auditor Access

AI-Augmented, Human-in-the-Loop Architecture

AI Anomaly Detection

Transaction Stream
AI Fraud and Anomaly Model
Flagged Transaction Queue

Human Review Checkpoint

Risk Analyst Review
Approve Transaction
Decline and Refund

Automated Action

Approved Transaction Ledger
Customer Notification
Case Closed Record

Continuous Learning

Analyst Decision Feedback
Model Retraining Pipeline
Updated Risk Rules

Integration-Heavy / Ecosystem-Connected Architecture

Billing Core

Subscription Engine
Invoice Generator
Payment Ledger

Finance Systems

Accounting Software Sync
ERP Revenue Sync
Tax Filing Service

CRM and Support

CRM Customer Record Sync
Support Ticket System
Customer Portal API

Analytics

Data Warehouse Export
BI Dashboard
Revenue Reporting

Ready to get started?

Tell us what you’re trying to get done and we’ll help you find the highest-leverage place to start, scoped small enough to prove itself before you commit to anything bigger.

Talk to us about Payments & Billing Engineer

Most engagements like this start as a $500–$2,500 pilot, see full pricing.