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Freight Audit & Pay: Legacy to Production in 6 Months

How AI-augmented engineers rebuilt the invoicing backbone of a U.S. delivery orchestration platform, and kept building.

How AI-augmented engineers rebuilt the invoicing backbone of a U.S. delivery orchestration platform.

  • Logistics
  • FinTech
  • Brownfield
Industries
Logistics, FinTech
Platform
Web application (SaaS)
Delivery scope
AI-accelerated engineering, legacy replacement, financial logic, brownfield integration

ABOUT THE PROJECT

Project overview

Engagement
Ongoing (1 year+)
Team size
6, joint with the client team
Core technologies
.NET/C#, Kubernetes

A U.S. delivery orchestration platform managing enterprise last-mile fulfillment. Billing complexity across shippers and logistics providers outgrew the legacy system — the team needed a purpose-built Freight Audit & Pay platform for multi-party invoicing, cost calculations, and dispute management at scale.

Limestone's AI-augmented velocity pod took full ownership of delivery, shipping a production-grade replacement integrated into the client's existing infrastructure.

A U.S.-based delivery orchestration platform helping enterprises manage last-mile fulfillment with a connected courier network and real-time visibility.

Billing complexity grew across shippers and logistics providers. The team needed a purpose-built Freight Audit & Pay platform.

Limestone embedded a velocity pod of AI-augmented engineers who took full ownership of delivery.

Challenge

Financial-grade logic at scale, without breaking what works. A new invoicing system had to ship fast, stay auditable, and never break the workflows already running underneath it.


  1. Multi-party billing at scale

    Replace the legacy Knack-based invoicing system with a scalable platform supporting billing across shippers and logistics providers.


  2. Financial-grade consistency

    Complex cost-calculation logic with tight data consistency requirements across multiple systems.


  3. Brownfield constraints

    Existing workflows and downstream consumers could not break during migration. Legacy behaviors were mapped and preserved before the new system took over.

    Existing workflows and downstream consumers could not break during migration. Legacy behaviors were mapped and preserved.


  4. Speed with auditability

    Requirements evolved as discovery surfaced edge cases, under pressure to ship value fast while maintaining auditability, security, and operational stability.

    Requirements evolved as discovery surfaced edge cases, under pressure to ship fast while maintaining auditability and stability.

WHAT WE DID

Solution

The Velocity Framework: six steps, every feature, every time.

  • Invoice Generation

    Traditional invoices for shippers and reverse invoices for logistics providers, integrating directly with delivery data.

  • Cost Calculation Engine

    Complex cost-targeting logic with stored properties, automatic recalculation on delivery changes, and support for Traditional and PostAdjustment invoice types.

    Complex cost-targeting logic with stored properties, automatic recalculation on delivery changes.

  • Dispute Management

    Full dispute workflow with status tracking, partial approvals, and resolution flows built from real auditor feedback.

  • Approval Workflows

    Configurable approval windows with Kubernetes CronJobs that automatically process expired invoices daily.

  • Reporting & Export

    Detailed invoice reporting with configurable columns, CSV export, and full transparency into dispute values.

  • Event-Driven Architecture

    Event-driven state changes keep downstream systems synchronized with billing activity in real time.

  • Cursor

    Primary development environment with Plan Mode.

  • Claude Opus

    Primary model for spec writing, plan generation, and code implementation.

    Primary model for spec writing and code implementation.

  • ClickUp

    Task management and requirement tracking, the starting point for every feature.

    Task management and requirement tracking.

Delivery Platform Core operations Data Warehouse Analytics & reporting Database Relational persistence API & Services .NET/C# on Kubernetes Workers K8s CronJobs Frontend Web app Event Bus Event synchronization Auditors Delivery audit & review
Database Relational persistence Delivery Platform Core operations API & Services .NET/C# on Kubernetes Workers K8s CronJobs Frontend Web app Event Bus Event synchronization Data Warehouse Analytics & reporting Auditors Delivery audit & review

A reliable, event-driven backbone.

Event-driven microservices on Kubernetes with message-based synchronization.

Relational persistence and integrations across the delivery and data infrastructure. Event-driven state changes keep downstream systems synchronized.

Relational persistence and integrations across the delivery and data infrastructure.

DELIVERY TIMELINE

From zero to production, then kept building.

Upper environments at roughly four months, production by months five to six, and the same Limestone team continues expanding the platform.

Upper environments at roughly four months, production by months five to six.

  1. WEEK 1-2

    Context & Onboard

    Knowledge graph first

  2. MONTHS 1-3

    Core Build

    122 PRs in 90 days

  3. MONTH 4

    Upper Environments

    Ahead of plan

  4. MONTHS 5-6

    Validation & Prod

    330+ PRs merged by month 6

    330+ PRs merged

  5. MONTH 7+

    Ongoing Development

    Same team, still shipping

DELIVERY APPROACH

In production ahead of plan. Brownfield, not a weekend prototype.

  • WEEK 1

    Context before code

    No code in the first week. The team scanned the entire repo and built a knowledge graph documenting every module, dependency, and data flow.

  • V.U.E.

    The V.U.E. gate

    The agent handles roughly 90% of code generation. A senior engineer reviews every PR, nothing merges unless they can verify, explain, and debug it.

    The agent handles roughly 90% of code generation. A senior engineer reviews every PR.

  • 50% FASTER

    Where the time savings came from

    Upfront context eliminated false starts, the agent handled mechanical coding so engineers focused on design and review. AI cost: $200/month

CLIENT FEEDBACK

The client paid the engineers discretionary bonuses. Twice.

  • TECH LEAD

    "True engineers capable of closing requirement gaps through fast domain discovery and iteration."

    "True engineers capable of closing requirement gaps."

    Tech Lead · Delivery Orchestration Platform · Anonymized

    Tech Lead · Delivery Orchestration Platform

  • PRODUCT TEAM

    "Product maturity level achieved unusually early."

    Product Team · Delivery Orchestration Platform · Anonymized

    Product Team · Delivery Orchestration Platform

  • VELOCITY STATS

    122 merged PRs in the first 90 days

    104 merged with fewer than 5 reviewer comments. 90% code generated with AI, reviewed by humans.

    104 merged with fewer than 5 reviewer comments. 90% code generated with AI.

ENGINEERS RECEIVED DISCRETIONARY BONUSES FROM THE CLIENT TWICE FOR EXCEPTIONAL DELIVERY

Impact & Results

  • Freight Audit & Pay platform deployed to upper environments in four months, in production by months five to six, still actively developed a year later.
  • Freight Audit & Pay platform deployed to upper environments in four months, in production by months five to six.
  • Legacy invoicing system replaced with a scalable, integrated platform.
  • 122 pull requests merged in the first 90 days with consistent quality; 104 required fewer than 5 reviewer comments.
  • 122 pull requests merged in the first 90 days; 104 required fewer than 5 reviewer comments.
  • 2 AI-augmented engineers maintained consistent high-velocity delivery.
  • Engineers received discretionary bonuses from the client twice.
  • Velocity Framework validated as a repeatable delivery system on a complex brownfield engagement.
  • Velocity Framework validated as a repeatable delivery system.
  • PRs merged in first 90 days

    122

  • AI-generated code, human-reviewed

    90%

  • faster development cycles

    50%