Modernized a 16-Year-Old Legacy Desktop App for SaaS

Rebuilding H5's internal, VPN-only DART tool into a browser-based SaaS product on the Relativity platform.

ROLE

Lead UX Designer and Researcher

15 yrs

of design debt resolved, workflows streamlined, and a design system introduced

COMPANY

H5 / Lighthouse

TIMELINE

11 / 2020 - 1 / 2023

100%

task completion rate in final usability round, up from 80%

TEAM

1 report, 3 Product Managers, 50 Engineers

DesktopSaaS

rebuilt from a VPN-only tool onto the Relativity cloud platform

The Problem

A 2005 desktop tool, still running in 2020.

DART was H5's internal desktop application for search strategists and reviewers, collection creation, complex query building, document analysis, accessible only over VPN on a virtual machine. Sixteen years without a UX designer had left real design debt, and the business needed it rebuilt as a browser-based product it could host on Relativity, legal-tech's version of Salesforce, to reach customers beyond internal VPN users.

Role & Constraints

PARTNERED ON

Product management and engineering throughout; a new Lighthouse design team post-acquisition.

CONSTRAINTS

VPN-only legacy access, sixteen years of accumulated debt, a design system alignment and expansion mid-project.

OWNED

UX design for DART's transformation into a SaaS product, managing a mid-level designer while supporting Matter Analytics in parallel.

WHAT CHANGED MID-FLIGHT

The PM departed and H5 was acquired by Lighthouse, both landed partway through the build.

The Approach

4 steps, one vision.

1. DISCOVERY: Usability audit against Nielsen's heuristics, plus user research into delights, pain points, and workarounds.

2. DEFINITION: Scoped an MVP against user, business, and design/technical constraints.

3. DESIGN & ITERATION: Benchmarked Salesforce and Relativity, then tested the Formula Builder through two R.I.T.E. rounds.

4. DELIVERY: Shipped incrementally, realigning to Lighthouse's design system mid-migration.

Key Decisions

Round 1: 80% success

Cut and consolidated the Formula Builder's buttons

Why: Users confused similarly-named buttons, mistook the move icon for a menu icon, and read red icons as errors.

Result: Removed color-as-signal outside of CTAs, consolidated redundant buttons, made the remaining ones more prominent.

Round 2: 100% success

Fixed the smaller usability gaps round one surfaced

Why: Some users still struggled with group creation, unclear micro-tasks, and small tap targets.

Result: Disabled-state for uneditable fields, larger tap targets, buttons de-emphasized to match the new design system, every tester completed every task unaided.

The Work

2005: Legacy desktop app

VPN-only, virtual-machine desktop interface.

2023: Streamlined SaaS app

Browser-based, cloud-hosted redesign for the Relativity platform.

Memorable Quotes

This is way better than what we’ve used for the last 10 years!
— Anonymous usability participant

Outcome

What shipped.

DART now runs on the Relativity platform, reaching customers beyond internal VPN users, with simplified workflows, greater feature discoverability, and reduced time-to-task. H5 was acquired by Lighthouse during this window, the modernized platform was part of the case for it.

Reflections

What I would do differently.

Clickable prototypes won arguments faster than static comps ever did. If I ran it again, I'd get in front of real users sooner, I spent more time than I'd like learning the problem secondhand through the PM before user conversations started.