Client Context & Problem
A U.S.-based B2B SaaS platform for dealerships, car-rental and fleet companies that manages toll payments across hundreds of thousands of vehicles. C4Scale has been the outsourced product and engineering partner from day one building, scaling, and operating the entire platform as a managed service.
Pain Points
- MVP needed complete toll-to-transaction mapping across multiple payment gateways
- Complex car-to-license-plate and plate-to-customer-contract mappings
- Required support for 5+ payment gateways (Stripe, Windcave, Tempus, CenPos, etc.)
- Invoice generation and QuickBooks integration for reconciliation
- Needed a partner to build AND operate the platform long-term
Key Challenges
Scalability
Scaling from $2k/month to multimillion ARR without breaking the system
Billing automation
No scalable billing engine for real-time toll transactions
Data mapping
License plates not reliably mapped to customer contracts
Multi-tenancy
Supporting thousands of dealers on a single platform
Project Goal
Build, launch and operate a subscription platform that could handle real-time toll transactions, map plates to contracts, generate accurate invoices, and scale from $2k/month to multimillion-dollar ARR.
Success Metrics
- Scale from $2k/month to multimillion ARR
- Support 100x client growth
- Maintain 99%+ CSAT during scaling
- Automate toll reconciliation and invoicing
Solution & Platform Architecture
We built and operate an AWS-based multi-tenant SaaS platform as a managed service. Microservices handle toll-to-transaction mapping, car-to-license-plate matching, license-plate-to-customer-contract mapping, and multi-gateway payment processing (Stripe, Windcave, Tempus, CenPos). Automated invoice generation integrates with QuickBooks for billing and reconciliation. AI-powered anomaly detection flags unusual toll patterns. We manage the entire product lifecycle from development to production operations, monitoring, and continuous optimization.
Architecture
Serverless-first AWS platform (us-east-2) combining API Gateway + Lambda (80+ route handlers) with ECS long-running services and AWS Batch for bulk processing. EventBridge drives event-driven scheduling across toll ingestion, payment reconciliation, and customer lifecycle flows. Amazon Textract and a GenAI LLM layer handle document intelligence (toll notices, plate images). Multi-gateway payment orchestration (Stripe, WindCave, Tempus, CenPos) is managed by a dedicated payments microservice, while Amazon Cognito secures all user pools and RDS PostgreSQL (accessed via RDS Data API / TypeORM) stores transactional data.
Key Components
- Amazon API Gateway — HTTP entry point with request routing and throttling
- AWS Lambda — Express-based gateway with 80+ route handlers and auth middleware
- Amazon ECS — containerised long-running microservices (Payments, Tolls, Recon, Customer Processor, Reconciler)
- AWS Batch — bulk toll ingestion and scheduled report generation
- AWS EventBridge — event bus, cron schedules, and routing rules across services
- Amazon Textract + GenAI LLM — OCR for toll notices and plate images; NLP document parsing and chatbot
- Multi-gateway payment orchestration — Stripe, WindCave, Tempus, CenPos via a single payments service
- Amazon RDS (PostgreSQL) — core transactional store via RDS Data API and TypeORM
- Amazon Cognito — user pools, JWT issuance, and identity management for fleet managers and customers
- SNS / SES / SMS notifications and QuickBooks accounting integration
Workflow
Event Ingestion
Toll events stream via API Gateway and Lambda
Plate Mapping
Event processor maps license plates to active contracts
Billing
Billing engine calculates toll fees and taxes
Payment
Payment service generates payment links and collects funds
Notification
Notification service sends receipts to dealers and customers
Reconciliation
Reconciliation service aggregates daily totals and surfaces anomalies
Dashboard
Dealers access dashboards for fleet usage and revenue
Platform Capabilities
Before
Manual toll reconciliations, no automated billing, invoices generated manually, no scalability
- •Manual toll reconciliation spreadsheets
- •License plates manually mapped to customers
- •Invoices generated by hand
- •No automated payment collection
- •System would break at scale
After
Dealerships manage fleets in a single portal, view near-real-time toll charges, automatically invoice customers, and reconcile hundreds of thousands of vehicles with minimal manual effort.
- •Real-time toll event processing
- •Automatic plate-to-contract mapping
- •Automated invoice generation
- •Automated payment collection
- •Single portal for fleet management
- •Near-real-time visibility into charges
- •Handles hundreds of thousands of vehicles
Impact & Results
ARR Growth
Client Base
Customer Satisfaction
Manual Work
Business Outcomes
- ARR grew from $2k per month to multimillion dollars
- Client base increased 100x
- CSAT consistently above 99%
- Minimal manual intervention required
Why C4Scale
Build AND Operate as managed service
We don't just build — we operate the platform 24/7 as an extension of their team
Complex integrations expertise
Multi-gateway payment processing (5+ gateways), QuickBooks integration, toll-to-transaction mapping at scale
Long-term partnership
The client continues to outsource product development and operations to us through sustained growth
Production operations excellence
Managed monitoring, incident response, continuous optimization, and 99%+ CSAT throughout scaling
Ready to transform your operations?
Let's discuss how C4Scale can help you achieve similar results