You will get your legacy .NET Framework app migrated to modern .NET 10
Rising Talent
Rising Talent
Project details
Your app runs on .NET Framework 4.x. It works, so nobody has touched it. But you are stuck on Windows-only hosting, and it gets harder every year to find developers who want to work on it.
I move legacy .NET Framework applications to modern .NET, and I have done it in production on an enterprise platform rather than on a demo project. That work covered configuration moved out of XML into JSON, Entity Framework to EF Core, OWIN to modern middleware, and every third party library that broke along the way. I have 14 years in C# and .NET and I led a team of 8 engineers as Technical Lead.
I do not quote a fixed price on a codebase I have not read. Every old solution hides something, and a number invented before I look at your code helps neither of us. The assessment tier gives you a real plan and a real number before any code is touched.
One thing I will be straight about. Large WCF estates that need a full gRPC rewrite, and Web Forms applications, are not my strongest ground. If that is most of your solution, the assessment will say so plainly rather than sell you work I am not the best person for.
I move legacy .NET Framework applications to modern .NET, and I have done it in production on an enterprise platform rather than on a demo project. That work covered configuration moved out of XML into JSON, Entity Framework to EF Core, OWIN to modern middleware, and every third party library that broke along the way. I have 14 years in C# and .NET and I led a team of 8 engineers as Technical Lead.
I do not quote a fixed price on a codebase I have not read. Every old solution hides something, and a number invented before I look at your code helps neither of us. The assessment tier gives you a real plan and a real number before any code is touched.
One thing I will be straight about. Large WCF estates that need a full gRPC rewrite, and Web Forms applications, are not my strongest ground. If that is most of your solution, the assessment will say so plainly rather than sell you work I am not the best person for.
Programming Languages
ASP.NET, C#What's included
| Service Tiers |
Starter
$349
|
Standard
$1,600
|
Advanced
$3,900
|
|---|---|---|---|
| Delivery Time | 5 days | 21 days | 45 days |
Number of Revisions | 1 | 2 | 3 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code | - |
Optional add-ons
You can add these on the next page.
Additional Revision
+$150
Extra project or class library migrated
(+ 5 Days)
+$450
Unit tests for one legacy module
(+ 4 Days)
+$600
CI/CD pipeline updated
(+ 3 Days)
+$550Frequently asked questions
About Phong
Senior .NET & React | Legacy .NET | SQL Design, Optimization | 14+ Yrs
Ho Chi Minh City, Vietnam - 1:41 am local time
𝗡𝗲𝗲𝗱 𝗻𝗲𝘄 𝗳𝗲𝗮𝘁𝘂𝗿𝗲𝘀 𝗯𝘂𝗶𝗹𝘁 𝗳𝗿𝗼𝗺 𝘀𝗰𝗿𝗮𝘁𝗰𝗵, 𝗳𝗿𝗼𝗺 𝘀𝗽𝗲𝗰 𝘁𝗼 𝘀𝗵𝗶𝗽𝗽𝗲𝗱?
I migrate ASP.NET MVC applications to .NET 6/8/10 and optimize the databases behind them, safely, incrementally, without breaking production.
I'm a Senior .NET Engineer and Technical Lead with 14+ years in enterprise C# .NET, React, and SQL Server. Most recently I led a team of 8 engineers on Wellbarrier, an enterprise SaaS platform delivered to SLB and used by major oil & gas operators worldwide. It's a large, long-lived codebase built across 4 Scrum teams. Legacy systems, complex data models, and production systems that can't afford downtime are my home ground.
𝗪𝗛𝗔𝗧 𝗜 𝗛𝗘𝗟𝗣 𝗪𝗜𝗧𝗛
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𝟭. 𝑳𝑬𝑮𝑨𝑪𝒀 .𝑵𝑬𝑻 𝑴𝑶𝑫𝑬𝑹𝑵𝑰𝒁𝑨𝑻𝑰𝑶𝑵 & 𝑼𝑷𝑮𝑹𝑨𝑫𝑬𝑺
• ASP.NET MVC on .NET Framework 3.5 / 4.x to ASP.NET Core / .NET 6, 8, 10 (LTS), including the 3.5 to 4.8 upgrade step for very old codebases
• Entity Framework 6 to EF Core: mapping changes, query behavior differences, and data-layer refactoring
• Legacy front ends (Razor, jQuery, AngularJS) rebuilt in modern React
• Every migration starts with an assessment: dependency audit, breaking-change map, and a phased plan, so you know the real cost and risk BEFORE the work begins
𝟮. 𝑫𝑨𝑻𝑨𝑩𝑨𝑺𝑬 𝑫𝑬𝑺𝑰𝑮𝑵 & 𝑶𝑷𝑻𝑰𝑴𝑰𝒁𝑨𝑻𝑰𝑶𝑵 (𝑺𝑸𝑳 𝑺𝑬𝑹𝑽𝑬𝑹)
• Schema design for new products, plus redesign of data models that grew messy over the years
• Rescuing slow queries, timeouts, and heavy reports: indexing, query tuning, execution plan analysis on large production datasets
𝟑. 𝑵𝑬𝑾 𝑭𝑬𝑨𝑻𝑼𝑹𝑬𝑺 𝑭𝑹𝑶𝑴 𝑺𝑪𝑹𝑨𝑻𝑪𝑯, 𝑭𝑹𝑶𝑴 𝑺𝑷𝑬𝑪 𝑻𝑶 𝑺𝑯𝑰𝑷𝑷𝑬𝑫
• Certified Scrum professional (PSM I, PSD I, PAL I, SPS from Scrum•org). I turn a rough idea into user workflows, acceptance criteria, and a sprint-ready backlog, then build it in C# .NET and React
• Ideal if you have a product vision but no written requirements yet
𝗪𝗛𝗬 𝗖𝗟𝗜𝗘𝗡𝗧𝗦 𝗪𝗢𝗥𝗞 𝗪𝗜𝗧𝗛 𝗠𝗘
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• 14+ years of hands-on development, with international clients since 2012 across e-commerce, recruitment, oil & gas, and SaaS
• 4+ years leading engineers: architecture decisions, code reviews, mentoring, sprint planning
• Enterprise discipline: clean code, unit testing, CI/CD, Git, refactoring without breaking existing behavior
• Clear written communication and reliable delivery across time zones. I typically respond within a few hours.
𝗛𝗢𝗪 𝗪𝗘 𝗖𝗔𝗡 𝗦𝗧𝗔𝗥𝗧
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• Small first: a fixed-price migration assessment, a database performance audit, or a feature specification package. You get a concrete deliverable and see exactly how I work. Then we scale up to the full migration, the new feature, or a long-term engagement.
• Available full-time, for focused projects or long-term contracts.
• Message me with your current .NET version, database, and main pain point, and I'll reply with an honest first take on the best path forward.
Steps for completing your project
After purchasing the project, send requirements so Phong can start the project.
Delivery time starts when Phong receives requirements from you.
Phong works on your project following the steps below.
Revisions may occur after the delivery date.
Read the codebase and run the analyzers
I run the .NET Upgrade Assistant and the Platform Compatibility Analyzer, then read the code myself. Tools find the obvious breaks. Reading finds the things that quietly stop working.
Send you the assessment
A written report: breaking changes with the fix for each, NuGet packages that need replacing, the risky areas, and a phased plan in dependency order. You get a real number before any code is touched.