Microsoft Platform Specialists · UK Based

Your .NET legacy.
Our deep expertise.

Senior engineers who've lived inside WebForms, VB.NET, classic ASP and SQL Server for decades — and know how to move them forward without breaking what matters.

.NET Framework C# VB ASP.NET WebForms SQL Server Classic ASP SharePoint Umbraco Sitecore Kentico DNN
LegacyMigrationService.cs
25+
Years on the MS stack

The engineers who actually
know your stack.

Most firms will tell you to rewrite everything in React and move on. We won't. Microsoft legacy systems — WebForms, VB.NET, classic ASP, bespoke CMS — contain decades of real business logic that can't be recreated from a spec document.

We've been working inside these systems since they were new. That experience means fewer surprises, faster diagnosis, and migrations that actually stick.

01

Microsoft-first depth

We don't dabble. The Microsoft stack is all we do — from .NET 1.1 to .NET 10, SQL Server 2000 to 2025.

02

Senior engineers only

No juniors handed the wheel. Every engagement is led by developers with 10+ years on the platform.

03

Preserve business logic

We extract, document, and protect the logic buried in your legacy code before touching a single line.

04

UK-based, always

Our entire team is in the UK. Same timezone, same accountability, no offshore handoffs.


What we
actually do.

From emergency support to full platform migration — built around the Microsoft technologies your business runs on.

🔧

Legacy .NET Support & Rescue

Ongoing maintenance, critical bug fixing and emergency support for .NET Framework applications that others won't touch — WebForms, WinForms, ASMX web services and more.

.NET 1.1–4.8 WebForms WinForms ASMX
🔄

Modernisation & Migration

Phased migration from legacy .NET Framework to modern .NET — retaining business logic while gaining performance, security and long-term supportability. VB.NET to C# conversions included.

.NET 6–10 Blazor Razor Pages Web API
🗄️

SQL Server Modernisation

Version upgrades, performance tuning, stored procedure refactoring, and migrations from SQL Server 2000/2005/2008 to current versions — including Azure SQL and SQL Managed Instance.

SQL Server 2000+ Azure SQL EF Core
🌐

Website & CMS Rescue

Classic ASP, old WebForms sites, end-of-life Umbraco, Sitecore, DNN and bespoke CMS platforms — we rescue, stabilise and migrate them to modern, maintainable alternatives.

Classic ASP Umbraco Sitecore DNN
☁️

Azure Migration & Cloud

Lift-and-shift or re-architect — we move your .NET and SQL Server workloads to Azure, leveraging App Service, Azure SQL, Functions, and the full Microsoft cloud ecosystem.

Azure App Service Azure SQL Azure Functions
🤖

AI & Copilot Integration

We integrate Microsoft AI capabilities — Azure OpenAI, Copilot Studio, AI Search — directly into your existing .NET and SharePoint systems. No full rewrite needed.

Azure OpenAI Copilot Studio AI Search


04 — Our Approach

Methodical. Transparent.
No surprises.

Legacy .NET projects have derailed before — usually because the team underestimated what was hidden inside the system. We don't make that mistake. Our process starts with understanding, not assumptions.

01

Codebase Archaeology

We read the code before touching it. Assembly analysis, dependency scanning, database schema review — we build a complete picture of what you have and what it does.

02

Honest Risk Assessment

We produce a plain-English risk register: what's fragile, what's undocumented, what's tightly coupled. No sales optimism — just the facts.

03

Phased Roadmap

We design a delivery plan that keeps your application running throughout — no big-bang rewrites, no single points of failure in the migration itself.

04

Direct Engineer Access

You work directly with the engineers doing the work, not account managers. Clear milestones, weekly updates, and no surprises.

05

Documentation & Handover

Every engagement closes with full documentation, architectural diagrams, and a handover your internal team can actually use.

05 — Full Technology Range

Everything we work with, organised.

Languages

C# VB.NET Classic ASP / VBScript T-SQL PowerShell JavaScript / TypeScript HTML / CSS

Frameworks & Platforms

.NET Framework 1–4.8 .NET 5 / 6 / 7 / 8 / 10 ASP.NET WebForms ASP.NET MVC 1–5 Blazor (Server / WASM) Web API / REST WCF / ASMX / SOAP WinForms / WPF Entity Framework (4–Core)

Data & CMS

SQL Server 2000–2022 Azure SQL / Managed Instance SSRS / SSIS / SSAS Umbraco Sitecore DotNetNuke Kentico SharePoint EpiServer Tridion

Cloud & Modern

Azure App Service Azure Functions Azure DevOps / Pipelines Azure OpenAI Copilot Studio Microsoft 365 Power Platform IIS 5 → Current

Built by engineers who
grew up on Microsoft.

Synesio was founded by senior .NET developers who were tired of watching businesses get burned by firms that didn't understand what was really inside their systems.

We're a tight, senior-only team based across the UK. No offshore handoffs, no juniors shadowing. When you hire Synesio, the engineers you meet in the first call are the engineers who do the work.

We've delivered for businesses in financial services, insurance, manufacturing, legal, retail, and the public sector — wherever Microsoft technologies are running systems that can't afford to go down.

25+
Years on the MS stack
80+
Projects delivered
100%
UK-based engineers
0
Junior-led engagements

07 — Contact

Got a .NET system
that needs attention?

No sales pitch, no slide deck. Just a conversation with an engineer who's probably worked on your version of the framework before.