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How custom middleware put HubSpot at the centre of CPG's sales stack

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How custom middleware put HubSpot at the centre of CPG's sales stack
0:20
Nearly

100

Custom Reports
Built

4

Custom Integrations
Integrated

5 Brands

In two portals
Built

20+

Custom Dashboards

Campbell Property Group (CPG) is a family-owned residential developer with five business units: Clarendon Homes NSW, Clarendon Homes QLD, Domaine Homes, CPG Estates and home loan brokerage Loan Market Elevate (LME). Engaging.io built the custom middleware that connects HubSpot to the four specialist platforms behind every CPG sale.

The problem
Built from scratch: why every integration had to be custom

Every CPG sale runs through specialist platforms: Framework for house types and pricing, ClickHome for tenders and contracts, PandaDoc for sales paperwork and SharePoint as the document record. Deal data and sales documents moved between them by hand, and CPG wanted HubSpot to become the one place where every deal is seen and acted on.

An earlier CRM project on Microsoft Dynamics had fallen short of its goals, so CPG’s leadership wanted proof before another platform change, and each specialist system needed to keep doing its job.

 

Problem 1:

No native connectors for the core platforms: Framework, ClickHome and SharePoint Online each expose custom or proprietary APIs with no published HubSpot connector. Each platform needed its API scoped, its data mapped to HubSpot objects and its own authentication method engineered. The standard PandaDoc integration added a further limit, because it could not combine templates, Framework estimates and customer files into one signable document.

Problem 2:

Keeping complex external systems in step with HubSpot: Framework, ClickHome and SharePoint each run on their own data model and triggers. Framework issues a new estimate version with every change, ClickHome holds the tender and contract dates that decide a deal's stage, and SharePoint is reached through the Microsoft Graph API. Referred home loan leads also needed to reach LME, which runs in its own HubSpot portal.

The solution
Architecture designed around the business
Engaging.io built a single bespoke middleware application in Laravel that connects HubSpot to Framework, ClickHome, PandaDoc and SharePoint Online, and passes referred leads into LME's portal.
The Strategic Plan
The Implementation
The process
To give CPG’s leadership the evidence they wanted, Engaging.io ran reverse demos of Framework and ClickHome, held scoping sessions with the Framework vendor, worked with Professional Advantage on SharePoint access, and mapped each platform’s API, data model and authentication.
Step 1: Scope every platform before choosing the architecture
The process
To give CPG’s leadership the evidence they wanted, Engaging.io ran reverse demos of Framework and ClickHome, held scoping sessions with the Framework vendor, worked with Professional Advantage on SharePoint access, and mapped each platform’s API, data model and authentication.
Step 2: Choose one custom middleware layer, built in Laravel
The process
Engaging.io weighed an iPaaS tool such as Zapier or Make against a dedicated middleware application. Per-task pricing would have grown with every estimate version and document, and the paperwork logic needed more control than chained connectors allow.

A single Laravel application gave built-in queues, scheduling and retry handling, with no per-transaction fees and one place for logic, logging and errors.
Step 3: Prove the hardest build first
The process
Sales paperwork was the largest gap in the standard integration, so CPG saw a working proof of concept of the PandaDoc paperwork engine before committing to the main build.

One rule shaped the paperwork engine: HubSpot stays the single source of truth. Editing is disabled for consultants in PandaDoc, so any change, such as removing a swimming pool option, goes back through the deal record and generates a fresh document. The paperwork and the CRM always match.
Step 4: Build on the shared layer, pilot with one brand, then extend
The process
Each platform received its own integration on the shared layer, with HubSpot holding the current record while the specialist platforms remain the working tools.

Clarendon Homes NSW went live first, proving the data model and integrations before the other business units and the LME portal followed. Two-day training, user guides and in-person sessions in Queensland supported adoption.

The Implementation


Campbell Property Group’s specialist platforms had no ready-made path to HubSpot. Framework, ClickHome and SharePoint Online each expose custom or proprietary APIs with no published HubSpot connector, and LME’s separate portal needed referred leads passed across from CPG’s main instance. Our response was a single bespoke middleware application, built in Laravel, that acts as the orchestration layer for every integration, with queue-based job processing so data moves reliably between systems that each run on their own triggers.


The Tech Stack

  • Middleware: Laravel (PHP framework), queue-based job processing for asynchronous and retry-safe data handling.

  • Authentication: OAuth 2.0 client credentials flow via Microsoft Entra ID (formerly Azure Active Directory) for SharePoint access; subscription-key authentication on Azure API Management for Framework.

  • APIs consumed: HubSpot CRM API v3 and v4, Microsoft Graph API, Framework REST API (Azure-hosted), ClickHome REST API v2, PandaDoc API.

  • HubSpot developer tools used: private app tokens, webhook subscriptions, HubSpot File Manager API, CRM object and association APIs.

The Architecture of the Configuration

Document status flow@1xIntegration overview@1x

Custom Integration 1: Framework - opportunity and estimates sync

Framework is CPG's core job management platform, handling quotes, job codes, and deal progression through the stages of residential property development. Creating a deal with a primary customer contact creates the Framework opportunity with customer and land and site details, and changes to mapped fields keep it current.

Consultants build estimates in Framework. Every version updates an estimates table and the job number, house type, facade, specification and price on the deal, and its PDF replaces the previous one.

Custom Integration 2: ClickHome - tender and contract sync

ClickHome tracks the progress of every home through the build. For this integration, deal creation also opens a ClickHome lead, kept current as job number, owner and site details change. From tender onwards ClickHome drives the pipeline: tender and contract presented and accepted dates sync back and move the deal stage. Sales and operations teams can see exactly where every home is in the build without leaving HubSpot or waiting on a manual update. 

Custom Integration 3: PandaDoc - sales paperwork engine

Checkbox properties on the deal, gated by deal stage, trigger eight document types, from the tender request fee to sales paperwork for the customer, vendor and operations. The middleware aggregates templates, the final Framework estimate and customer files into one document with embedded signature fields, usually within one to three minutes.

The locked draft appears on the deal for review and sending, and the signed document and signature certificate sync back. Rules per business unit run from a JSON configuration, and an Integration Notes property surfaces any processing errors on the deal.

Customers can sign by email or in person. Once every party has signed, a webhook prompts the middleware to collect the signed PDFs and signature certificates and file them into the matching file properties on the deal, replacing the drafts.

As shown below in Image 1 and 2, the documents can be triggered in HubSpot to generate a template in Pandadoc, which uses properties pulled directly from HubSpot:

Image 1

Screenshot 2026-10-21 at 12.35.35 pm

Image 2 - The corresponding template generated in Pandadoc

Screenshot 2026-10-14 at 1.05.18 pm

Custom Integration 4: SharePoint document record

The middleware creates a folder per deal through the Microsoft Graph API, files every estimate and signed document, writes the folder mapping back to HubSpot, and listens for status webhooks so each document shows as uploaded or complete.

Portal Sync: Cross-portal sync: CPG to Loan Market Elevate

LME launched with its own HubSpot portal and a five-broker team. The middleware and custom-coded workflows pass referred leads and deals from CPG’s main portal into LME’s portal, triggering lead allocation, pipeline stage updates and workflow automation for the brokers.

Across both portals, Engaging.io configured over 100 custom properties, and 20+ workflows, alongside 20+ dashboards and nearly 100 custom reports spanning Clarendon Homes NSW, Clarendon Homes QLD, Domaine Homes, and CPG Estates.

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The Impact and Results
From disconnected systems to a unified data environment

Before go-live, deal data and sales documents moved between Framework, ClickHome, PandaDoc and SharePoint by hand, and there was no single view of deal data across the brands.

Now, multi-part sales paperwork is assembled in one to three minutes inside HubSpot and buyers receive one consolidated pack to sign. Consultants see the latest estimate and price without opening Framework, the pipeline updates itself from tender onwards, and every document is filed to SharePoint with its status on the deal. Referred home loan leads reach LME’s brokers through the same workflow.

For buyers, signing is simpler too: one consolidated pack, signed by email or in person, in place of separate documents arriving from different systems.

After go-live, every one of those manual handoffs is automated. Sales advice documents generated in Framework land on the correct HubSpot deal record without anyone touching them. Construction milestones from ClickHome flow through to the sales team in real time. A lead captured in CPG's main portal can be allocated to an LME broker within the same workflow. And for the first time, CPG's leadership has cross-brand reporting across five distinct business units in a single platform.

Operational metrics: 35 hours per week saved in the Sales team by eliminating manual data entry between Framework and Dynamics. 
70+ Active users in HubSpot

Because every deal now carries the latest estimate, signed paperwork and contract status as structured data, HubSpot’s AI features have complete deal context to work from as CPG moves past the adoption phase. The unified data environment Engaging.io has built with clean, structured contact and deal records across five brands and two portals, with live sync across all four external systems, establishes the prerequisite data architecture for Breeze AI features including predictive lead scoring and AI-driven workflow automation. When CPG moves into that next phase, the foundation is in place. No data remediation will be required before activation.

Before EIO, our teams were operating across five separate systems with no single view of a deal or a build, and no reliable way to act on it. Now, everyone from sales to service is working from the same data in real time - and it's changed how we run the business. That's given us visibility we've never had before across the group.

Schliebs, R.
CTO

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