Legal Tech Software: Apps Made with C# and .NET

The eDiscovery platform trusted by 13,000+ organizations worldwide, including 70 of the AmLaw 100 largest law firms, builds its core product with C# and .NET on Azure. That platform is Relativity, and it sits at the center of major litigation across the legal industry. The pattern holds well beyond eDiscovery. The document automation software that legal professionals use to draft contracts and forms asks C# of every developer who integrates with it. The data analytics platform behind LexisNexis risk tools names C# and .NET in its principal engineering roles. Legal technology runs deeper on the Microsoft stack than most developers assume when they picture where C# lives. This post walks through five documented examples, closing with a capital markets title company where Softwarium built AI-powered document recognition on a modern .NET foundation.

Relativity describes its mission as helping teams organize data, discover the truth, and act on it. The platform serves 13,000+ organizations worldwide, including 70 of the AmLaw 100 law firms. A single litigation environment can hold millions of documents, and every one of them has to be reviewed, classified, and produced against court-ordered deadlines. Litigation software carries little room for error at that volume, since a misclassified document can decide what surfaces as evidence and what stays buried.

Relativity builds this platform using C# and .NET on Azure, confirmed by published engineering job descriptions. One active posting spells out the work directly:

Another posting lays out the full stack behind the product:

The engineering team responsible for evidence review at this scale chose C# and .NET as the primary backend language. That choice reflects what legal data demands. Strong typing, mature enterprise libraries, and native SQL Server integration give the platform a dependable foundation for handling document volumes that reach into the millions per matter, with the tamper-evident audit trail that legal review requires: who opened which document, when, and what they did with it. For a team evaluating the Microsoft stack for a new legal product, Relativity answers a practical question about what C# handles at enterprise legal scale.

Sources: Built In Chicago Relativity jobs and the software engineer posting with the stack listed.

HotDocs turns standard legal documents, from wills and contracts to pleadings and court forms, into intelligent templates that populate automatically from client or matter data. The software removes the manual cut-and-paste that legal document production normally involves, which is one of the more time-consuming parts of daily practice.

HotDocs’ official developer documentation identifies .NET Framework and C# as the standard approach for building host applications. The documentation states it plainly:

The HotDocs Server .NET API is a set of native .NET classes. Developers reference HotDocs.Server.dll in their ASP.NET host applications, and the documented requirement is Microsoft Visual Studio with C# libraries installed. C# is the documented path for modern host application development rather than one option among several. The legal document automation software that has taken millions of hours of manual drafting out of legal practices runs on C# and .NET.

Source: HotDocs Server .NET API documentation.

LexisNexis Risk Solutions is the data analytics arm of LexisNexis, a separate division from the legal research and Westlaw products. It supplies risk assessment, compliance, identity verification, and fraud detection tools to legal and regulated organizations. A published engineering role at risk.lexisnexis.com carries its stack in the job title itself:

A principal-level role naming C# and .NET in the title signals that these are primary technologies in the risk platform’s engineering stack, not peripheral ones. Legal and regulated industries lean on LexisNexis Risk Solutions for compliance screening, identity verification, and fraud detection, and the data engineering behind those decisions has to integrate cleanly with the matter management, billing, and compliance systems around it. C#/.NET’s mature API ecosystem supports the multi-system integration that enterprise legal deployments call for. The confirmed scope here is the Risk Solutions division and its data analytics products.

Source: LexisNexis Risk Solutions engineering posting.

iManage is the document and email management platform used by thousands of law firms and legal departments worldwide. Matters get organized there, work product gets filed, and client documents get stored and retrieved through it. When a firm needs to connect that system to its practice management tool, billing platform, or a custom workflow, C# tends to be the language that connection gets written in.

Developers integrating with iManage Work use C# through the platform’s .NET-friendly SDK, confirmed via Microsoft’s official Power Platform connector documentation and iManage’s own developer documentation at docs.imanage.com. The iManage Full Stack Developer certification covers iManage Work SDK development with C# and .NET frameworks. The integration layer that ties a firm’s systems to the document management platform its lawyers work in every day is C# territory. This is C# as the developer integration language, in the same way the Azure SDKs expose C# without the underlying service itself being written in it.

Sources: Microsoft Power Platform connector for iManage and iManage developer documentation.

ProTitleUSA is a capital markets title search company processing high volumes of mortgage documents, collateral loan files, title and tax reports, and due diligence packages. It sits in the legal infrastructure behind property transactions at institutional scale. Document review, meaning the categorization, extraction, and validation of legal document data, had become a core operational bottleneck. Softwarium built the engineering solution across four connected workstreams, each documented in a published case study.

The first workstream tackled recognition:

The workstream Softwarium anchors on the Microsoft stack is the platform migration:

Case studies: AI document recognition and .NET modernization.

The five examples share a set of engineering requirements that legal software imposes, and C#/.NET answers each of them.

C# reaches from the eDiscovery platform at the center of major litigation, to the document automation software that drafts legal forms, to the data analytics behind legal risk tools, to the integration layer of a widely used legal document management system, and out to AI-powered document recognition at capital markets scale. The requirements legal software carries, meaning document volume, audit trails, enterprise integration, compliance precision, and Windows-native interoperability, line up closely with what C# and .NET were built to handle. For related reading, see the enterprise .NET applications hub and the round-up of surprising C# software examples.