How to Choose a .NET Development Company

Choose a .NET development company by testing depth, not breadth. Ask which version of .NET their recent work runs on, how they build front ends (Blazor or a JavaScript framework against an ASP.NET Core API), what they have deployed on Azure, whether they have migrated a .NET Framework application without a rewrite, and how they test. Then look at the people you would actually work with, who owns the code, and what happens after launch. The twelve questions below, with the answers you want to hear, cover all of that in the order a first conversation usually runs.

Why .NET vendors differ more than they look

Almost every custom software firm lists .NET somewhere on its site, because C# has been a mainstream language for two decades. The listing tells you nothing. The gap between a firm that maintained one ASP.NET WebForms intranet a decade ago and one that ships ASP.NET Core applications on Azure every month is enormous, and both describe themselves as a dot net development company.

Three things drive the difference. First, modern .NET (8, 9 and later) is a different platform from .NET Framework: cross-platform, container-first, with new hosting, configuration and front-end models. A team that has not made that shift will build you something that is out of date on day one.

Second, the front-end decision (Blazor versus React or Angular) shapes hiring and maintenance for years, and many vendors only know one side. Third, Azure competence varies from “we can deploy to App Service” to designing landing zones, pipelines and cost controls.

If you are still deciding whether .NET is the right platform at all, read our assessment of where .NET stands first. The rest of this guide assumes you have decided and now need the right partner.

12 questions to ask a .NET development company

1. Which .NET version does your recent work run on?

You want to hear a specific current version and a habit of upgrading annually, with a reason for choosing long-term support releases. A vague “we do all versions” or examples that are all .NET Framework 4.x are a sign the team lives in the past. Ask to see a project started in the last year.

2. How do you build front ends, and why?

A good answer names both options and explains when each fits: Blazor when the team is C#-first and the application is form-heavy or internal; React, Angular or Vue against an ASP.NET Core API when a separate front-end team exists or public SEO matters. A firm that has only ever done one should say so. Our guide on Blazor vs React gives you the vocabulary to judge the answer.

3. Which Blazor render modes have you shipped?

Since .NET 8, Blazor applications can mix static server rendering, Interactive Server, Interactive WebAssembly and Interactive Auto per page. Someone who has built real Blazor applications will have opinions about when WebAssembly’s download size matters, when a SignalR connection per user becomes a scaling concern, and how prerendering affects SEO. Someone who has only read about Blazor will not.

4. What have you deployed on Azure, and how do you manage cost?

Listen for specific services (App Service, Azure Functions, Container Apps, AKS, Azure SQL, Key Vault, Service Bus, Application Insights), infrastructure as code (Bicep or Terraform), environment separation, and a view on cost: reserved capacity, right-sizing, when serverless is cheaper and when it is not. Ask whether they can also work on AWS or Google Cloud if that is where you are.

5. Have you migrated a .NET Framework application without rewriting it?

Most organizations hiring .NET help have an existing application. Ask how the vendor approaches it: an assessment with Microsoft’s .NET upgrade tooling, dependency analysis, the choice between in-place upgrade and a strangler-fig migration, and what they do about WebForms and WCF. The .NET Framework migration guide describes what a good answer contains.

6. How do you test, and who does it?

You want unit and integration tests written with the code, automated UI tests with a tool such as Playwright, performance testing before launch, and security testing against the OWASP Top 10. Ask whether QA is a separate discipline with its own people or something developers do at the end of a sprint. Ask to see a test report from a past project with the client’s name removed.

7. How do you handle authentication, secrets and compliance?

Expect Entra ID or ASP.NET Core Identity with OpenID Connect, secrets in Key Vault rather than configuration files, dependency scanning in the pipeline, and an understanding of whichever rules apply to you: HIPAA for health data, SOC 2 if your customers ask for it, PCI DSS if you take cards. If the vendor builds for regulated industries, they should be able to describe the controls without looking them up.

8. What does your delivery process look like week to week?

A concrete answer sounds like: discovery and a written proposal, two-week iterations with a demo at the end of each, code review on every change, a CI/CD pipeline from the first week, and a staging environment you can log into. A vague answer about agile methodology without those specifics usually means the process is whatever the current developer prefers.

9. Who exactly will work on our project?

Ask for the names and roles of the people, not the company’s total headcount. Find out where they are located, what the time-zone overlap is, who your single accountable contact is, and what happens if someone leaves. Onshore-offshore teams work well when there is a named lead and overlap hours; they work badly when you are handed to a rotating cast.

10. Who owns the code, and what do we get at handover?

The answer should be: you own the code and the intellectual property, it lives in a repository you control from day one, and handover includes documentation, infrastructure definitions, pipeline configuration and a list of third-party licenses. Any vendor that keeps the repository or uses a proprietary framework you cannot take elsewhere is building lock-in.

11. What happens after launch?

Software on modern .NET needs patching, dependency updates and a version upgrade every year or two. Ask what the maintenance options are (a managed service under a defined SLA, a retainer, or ad hoc work), how fast they respond to a production incident, and whether the people who built the application are the ones who will support it.

12. Can you show us something you built and still run?

Case studies with client names removed are fine, but the strongest evidence is a product the firm built and operates itself, because running software in production teaches lessons that project work does not. Ask for a walkthrough of a real codebase, even a small one, and watch how they explain the decisions in it.

Red flags

• Every example is .NET Framework. The team has not made the move to modern .NET and will build you a legacy system.
• A quote before discovery. A fixed price for an undefined scope is a guess, and someone will pay for the gap later, usually you.
• No separate QA. If testing is something developers “do as they go” with no people, tools or reports to show, expect defects in production.
• Placeholder credibility. Round numbers of happy clients, logos that do not match the case studies, awards with no source. If the website is not honest, the proposals will not be either.
• Only one architecture. Microservices for everything, or a monolith for everything. Good engineers choose based on the problem.
• No one accountable in your time zone. Offshore delivery works; offshore delivery with no onshore lead and no overlap hours usually does not.
• Vagueness about code ownership. If it takes more than one sentence to explain who owns the code, assume it is not you.
• Nothing to show. No codebase walkthrough, no product of their own, no references you can call.

Pricing models you will be offered

Most .NET development services are sold in one of four ways. None is better in general; each fits a situation.

Model	How it works	Fits when	Watch for
Fixed-scope project	A defined deliverable, a written price and schedule	A first version, a defined module, a migration with clear boundaries	Scope defined before the quote; a change process for everything else
Time and materials	You pay for hours worked, usually with a monthly estimate	Evolving requirements, research-heavy work	Weekly reporting and a cap you agree in advance
Dedicated team or staff augmentation	Named engineers on a monthly basis, inside your process	You have a product owner and a backlog and want to hire .NET developers without recruiting	Interview the people; agree notice periods for scaling down
Managed services	The vendor runs and supports the application under an SLA	After launch, or for systems you do not want to staff internally	Defined SLAs, a clear change budget and an exit clause

What drives the price inside any model is the same: the number and complexity of screens and integrations, data migration, compliance requirements, the amount of testing, and how much of the team sits in the US versus offshore. Ask any vendor to show you those drivers in their estimate rather than a single number.

Where PS3G fits

PS3G provides .NET development services for organizations of every size, from a founder’s first version to a department inside a larger company: ASP.NET Core applications and APIs, Blazor and JavaScript front ends, Azure infrastructure, .NET Framework migrations, and QA from a testing center of excellence. We work from Wilmington, Delaware and an India delivery center, under fixed-scope projects, dedicated teams or managed services. We also build and run our own software, including our HIPAA-compliant EHR and telehealth platform, DocVilla, which runs on ASP.NET MVC, so question twelve is one we are glad to be asked.

Related reading

• .NET Framework End of Life: How to Migrate to Modern .NET
• Is .NET Still Relevant for Business Software? An Honest Assessment
• Blazor vs React: Which Front End for Your .NET Application?

Frequently asked questions

Should we hire .NET developers directly or use a development company?

Hire directly when you have a technical lead who can interview, manage and retain developers and the work will last for years. Use a company when you need a team quickly, when the work has a defined end, or when you lack someone to lead it. Many organizations do both: a small internal core plus a vendor team that scales up and down with the roadmap.

How important is Microsoft certification when choosing a .NET vendor?

Useful but not decisive. Certifications show that engineers have studied the platform, and a firm that invests in them tends to keep its skills current. Shipped work matters more: a walkthrough of a recent ASP.NET Core codebase, a deployed Azure environment, and a test suite tell you more than any badge. Ask for both.

Is an offshore .NET development company a risk?

The risk is in the structure, not the geography. Offshore teams with a named onshore lead, overlapping working hours, your repository and your tools deliver well and cost less. The failures come from no accountable contact, rotating staff and work that happens entirely out of sight. Ask how the team is structured and who you call when something goes wrong.

What should a .NET development proposal include?

A statement of the problem in your words, the proposed architecture and stack with reasons, the scope broken into deliverables, the team by role, the process and cadence, the testing approach, the hosting and cost assumptions, what you own at the end, the maintenance options, and a price tied to the scope with a change process. If any of these is missing, ask for it before you sign.