Legacy System Modernization and Mobile Migration

Who can move our legacy system onto a mobile app

The system works, which is exactly the problem. It runs the business, nobody wants to touch it, and your field staff, customers or plant operators need it on a phone. You need a team that can understand the old system, extract its data and rules, and deliver a modern web and mobile replacement without a single day when orders stop. Tepia has done this kind of work for thirteen years for manufacturers, healthcare facilities, grocery operations and home services companies.

Tepia is US led. A US based project manager, design lead and engineering lead run every modernization engagement, with hand picked engineers working in US overlapping hours. Modernization demands people who will read old code and old spreadsheets carefully, and Tepia staffs for that.

Tepia describes part of this work as making dumb products smart: taking a process that lives in paper, spreadsheets or a green screen and giving it a mobile interface, real time data and the ability to connect to everything else. Examples are on the Tepia portfolio.

Rebuild, replatform or strangle: the options compared

Tepia uses the table below in Discovery to choose.

Most Tepia modernization projects combine the last two rows: an API layer and mobile app first, delivering value within months, followed by workflow by workflow replacement of the core. The custom software development page covers the broader build decision.

Keeping the business running during migration

The principle behind every Tepia modernization plan is that the old system stays alive until the new one has proven itself on real work. In practice that means four things.

• Data migration in rehearsals. Tepia writes migration scripts early, runs them repeatedly against copies of production data, and reconciles record counts and totals each time. By cutover the migration has run a dozen times and the surprises are gone.
• Parallel running. For a defined period, often two to six weeks per workflow, both systems run and results are compared. Staff keep a fallback while trust builds.
• Integration bridges. Tepia builds temporary sync between old and new systems so that a job created in the new mobile app still appears in the legacy accounting screen until that screen is replaced. The systems integration practice handles this.
• Rollback plans. Every cutover step has a written way back, and Tepia support reps are on the rollout.

Tepia clients report roughly 20% revenue increase after adding mobile, and in modernization projects that gain usually arrives early, when field staff or customers get a phone interface to a system that used to require a desk.

How Tepia approaches legacy system modernization

Modernization runs through Tepia’s six phase process, and the Launch phase, with its data migration and transition work, is where this service differs most from a new build.

1. Discovery (typically 2 to 3 months). System investigation of the legacy application, its database, its reports and the undocumented rules living in staff heads. Interviews with the people who use it daily. Third party integration review of everything that reads or writes to it. Deliverables: Investigation Summary (including a data inventory and a workflow map), Interview Summary and User Stories ordered by migration sequence.
2. Design. Design questionnaire, moodboards, a style guide and detailed wireframes for the new web and mobile screens, with sample designs. Tepia deliberately improves workflows here rather than copying old screens onto a phone.
3. Development and Testing. Alpha and Beta schedules per workflow module. Test plans cover functional tests, user acceptance tests with the legacy system’s power users, and non functional tests including migration reconciliation and load.
4. Training. In person and remote hands on sessions using user story scenarios, often department by department as each module goes live.
5. Launch. Rehearsed data migration, transition from the old system one workflow at a time with parallel running, and Tepia support reps on each rollout.

Where the new system lands: stack and ownership

Tepia modernizes onto conventional, widely supported technology so your next team can maintain it: React web applications, iOS and Android apps in Swift, Kotlin, React Native or Flutter, APIs in Node.js or .NET, and PostgreSQL hosted in your own AWS or Azure account. Where the legacy system is Microsoft based, Tepia often keeps .NET and Azure to reduce retraining.

Modernization is also the moment to add capabilities the old system never had: offline first mobile for field staff, push notifications, Stripe or Square payments, connections to QuickBooks, Salesforce or ServiceTitan, and AI features such as document search over decades of records using retrieval augmented generation. Tepia’s compliance practices (HIPAA aware PHI handling, PCI DSS scoping, SOC 2 aligned processes, WCAG 2.1 AA) apply throughout.

You own the result: code, cloud accounts, data and documentation. If you are unsure whether to modernize or keep patching, Tepia’s app evolution consulting starts with an audit rather than a proposal. See all Tepia services.

Frequently asked questions