A 40-attorney firm replaced an unsupported case management system and three side tools with one matter record in 20 weeks. This case study covers the legal case management software development behind it: what we built, what we chose not to build, and what the firm measured afterwards.

The situation: four tools, no single matter record

The firm handled litigation and commercial work across two offices. Its case management product ran on a server in a closet, and the vendor had ended support. Around it, staff had built workarounds.

  • Conflict checks: a paralegal searched a spreadsheet, the old system and the billing tool by hand. A matter with many parties could take most of an afternoon.
  • Intake: new matter details went into the case system, the billing system and a shared drive folder. Staff typically typed them three or four times.
  • Deadlines: court dates lived in the old system, but attorneys trusted their own Outlook calendars. The two drifted apart.
  • Documents: files sat on a network share. Folder names were the only index.

Nothing failed in a dramatic way. The cost showed up as re-keying, missed handoffs and partners asking the same conflict question twice.

If your firm's matter data lives in four places, start a project like this one and get a scoped plan for pulling it into one record.

The goal and the constraints

The goal was easy to state. Each matter would have one record holding its parties, deadlines, documents, contacts and unbilled time, searchable in seconds.

The constraints shaped every decision after that.

  • Deadline: the server's hardware warranty and operating system support ran out in about five months. That set a 20-week window.
  • Trust accounting stays put: the firm's accounting system handled client trust accounts and passed audits. Nobody wanted to touch it.
  • Confidentiality: the duty of confidentiality in the ABA Model Rules of Professional Conduct applies to software as much as to paper. Client data had to stay in the firm's own cloud tenant, with access limited by matter.
  • No cutover during trial prep: two large trials were on the calendar. Go-live could not land in those weeks.
  • Fifteen years of data: the history included duplicate client records and party names spelled several ways.

Legal case management software development: what we built

We built a web application on the firm's existing Microsoft 365 and Azure footprint. Four engineers and a designer did the work over 20 weeks.

Stack

  • React and TypeScript for the front end
  • ASP.NET Core for the API
  • PostgreSQL on Azure, with the pg_trgm extension for fuzzy name matching
  • Microsoft Entra ID single sign-on, so staff use their existing logins
  • Microsoft Graph for Outlook calendars and SharePoint documents

The matter record

Every matter has one page. It shows parties and their roles, related matters, key dates, documents, notes and unbilled time. Access follows the matter, so an ethical wall hides a screened matter everywhere, including search results and exports.

We used the NIST Cybersecurity Framework as the checklist for logging, access reviews and backups. Every view of a walled matter is logged with user and time.

Conflict checks

New intake runs a check against every party, alias, former name and related entity in the database. Trigram matching means “Smyth Holdings LLC” surfaces “Smith Holdings, L.L.C.” The paralegal reviews ranked hits and records a decision, which is stored with the matter for audit.

Deadlines and calendars

Deadlines are created in the matter record and pushed to the responsible attorneys' Outlook calendars. The matter record is the source of truth. If someone edits the Outlook event, the app flags the mismatch instead of silently overwriting either side.

Accounting integration

Approved clients and matters flow to the accounting system through its import API. Time entries follow nightly. Trust balances come back read-only, so attorneys see them without opening a second system.

The hard decision: what not to build

The firm first asked whether to buy a product off the shelf. We compared three paths with the partners and the operations manager.

Buy a cloud practice management product

This is the fastest start, usually with per-user monthly pricing. The trade-off: the firm's conflict process and ethical wall rules did not fit the vendor's data model without workarounds. Migration still needed custom scripts.

Build everything, including billing and trust

This gives full control. The trade-off: the firm would own compliance with state bar trust account rules and the audit trail. That is the riskiest part of any firm's software, and it already worked.

Build the matter record, integrate the rest

This is what we chose. The firm got a matter model that fits how it works, and kept proven accounting. The trade-off is two systems instead of one, plus an integration someone has to watch.

The deciding factor was risk, not cost. A bug in conflict search gets caught by a paralegal reviewing hits. A bug in trust accounting can become a bar complaint, so we left that job with software that had already passed audits.

What changed after go-live

These results come from the firm's own tracking in the first three months. They are ranges and directions, not lab numbers.

  • Conflict checks: complex checks went from hours to typically under 15 minutes, including review.
  • Intake: matter details are entered once instead of three or four times.
  • Calendars: docketing staff dropped the weekly manual reconciliation between the old system and attorney calendars.
  • Infrastructure: the old server was retired on schedule, before the first of the two trials.
  • Adoption: most attorneys used the app daily within a month. A few still email the paralegal instead, which is a training gap rather than a software one.

What we would do differently

The build went to plan. The data did not.

  • Start data cleanup in week one. Merging duplicate clients and normalising party names took longer than any feature.
  • Put a docketing clerk in every demo. Partners approved screens that the people entering deadlines later asked us to change.
  • Build integration monitoring first. In the early weeks, a failed nightly sync was found when someone noticed missing time.
  • Migrate one practice group first. We did a single cutover weekend. A staged move, with the old system kept read-only, would have cut the weekend work.

How a project like this starts

We start with a two-week discovery. It ends with a plan the firm can approve or walk away from.

  1. Map the matter lifecycle from intake to closing, with the people who do each step.
  2. Pull a sample export from the current system to see real data quality.
  3. Decide what stays, usually accounting and trust, and what gets replaced.
  4. Produce a scoped plan, timeline and estimate.

For a firm of 20 to 60 attorneys, a build like this typically runs 16 to 28 weeks. Data migration and the number of integrations drive most of the variance, so we estimate those first.

FAQ

How much does custom legal case management software cost?

For a mid-sized firm, a matter system with conflict checks, calendar sync and accounting integration typically costs $150,000 to $400,000 to build. Data migration and integrations cause most of the spread. Hosting and support add a monthly cost on top.

Is custom software safer than a cloud product for client confidentiality?

Not automatically. Custom software can run in your own tenant, with access and logs you control. You also own patching and access reviews, so ask any builder or vendor how ethical walls apply to search and exports.

Can we keep our current billing and trust accounting system?

Usually yes, and we recommend it if it passes audits. Most law firm accounting products offer an import API or scheduled file exchange. The matter system sends clients, matters and time, and trust balances come back read-only.