Moving from an on-premises SharePoint Server environment to SharePoint Online is rarely a straightforward case of copying and pasting files. While moving documents and site structures is relatively simple, the real challenge in any legacy SharePoint to SharePoint migration lies in managing technical debt: the customisations, server-side code, InfoPath forms, and classic workflows built over years of operational use.
With support deadlines approaching for legacy SharePoint Server editions, organisations need to modernise their application layer as well as their data. Trying to lift and shift outdated customisations into Microsoft 365 is often not possible and can create serious performance and security issues.
A framework for planning a SharePoint-to-SharePoint Migration
Here is a practical framework for auditing legacy technical debt and replacing outmoded customisations with modern Microsoft Power Platform and SharePoint Framework (SPFx) solutions.
- Auditing Technical Debt Before You Migrate
Before launching a migration tool or mapping drive letters, carry out a full discovery audit of your existing SharePoint farm. Migrating broken, unused, or duplicated customisations adds cost, complexity, and unnecessary delay.
Key Elements to Catalogue
- InfoPath Forms: Identify all published forms, form libraries, and embedded code-behind files. InfoPath is fully deprecated in the cloud environment and requires direct replacement.
- Classic Workflows: Map out SharePoint 2010 and 2013 workflow engines. Microsoft 365 no longer executes these legacy engines natively.
- Custom Code & Server-Side Solutions: Catalogue all .wsp packages, web parts, event receivers, and HTTP modules. Full-trust server code cannot run in SharePoint Online.
- Hardcoded Dependencies: Audit custom JavaScript, hardcoded URLs, and direct SQL queries that point to internal databases.
- Modern Replacement Strategies
A SharePoint-to-SharePoint migration is a good opportunity to replace legacy customisations with modern, supported approaches across Microsoft 365.
| Legacy SharePoint Component | Modern Microsoft 365 Replacement | Primary Business Benefit |
| InfoPath Forms | Microsoft Power Apps | Responsive mobile design, native canvas integration, and rich connector ecosystem. |
| SharePoint Designer Workflows | Microsoft Power Automate | Cloud-native automation that connects SharePoint with more than 1,000 internal and external systems. |
| Full-Trust Code (.wsp Packages) | SharePoint Framework (SPFx) | Client-side, secure web parts built using modern JavaScript frameworks (React, TypeScript). |
| Server-Side Event Receivers | Azure Logic Apps / Webhooks | Event-driven, serverless computing that isolates custom logic from the SharePoint core. |
- Transitioning Workflows and Forms Step-by-Step
Modernising Forms with Power Apps
Rather than trying to convert complex InfoPath XML templates like for like, start by reviewing the business process behind each form. Rebuild custom list forms in Power Apps so teams can use modern controls, clear validation rules, and Microsoft Entra ID for identity management.
Migrating Automation to Power Automate
Legacy workflows often combine multiple business steps into single, monolithic processes. When rebuilding these in Power Automate:
- Split long, brittle workflows into smaller, modular flows triggered by specific data actions.
- Use native approval actions to route documents through Microsoft Teams and Outlook.
- Store business logic outside of site column definitions to ensure flows remain reusable across different document libraries.
- Mitigating Risk with a Phased Rollout Plan
A lower-risk SharePoint to SharePoint migration works best as a phased programme, not a single high-pressure cutover.
Modernise Your SharePoint Environment with Bridgeall
Replacing legacy server-side code, InfoPath forms, and classic workflows requires a balanced mix of infrastructure expertise and application development capability.
As a certified Microsoft Solutions Partner, Bridgeall provides end-to-end SharePoint to SharePoint migration services, helping organisations assess technical debt, redesign legacy architecture, and move smoothly to SharePoint Online and the Microsoft Power Platform.
Ready to plan your SharePoint migration? Contact Bridgeall’s Microsoft consultants today to schedule an initial architecture assessment.
