Turn legacy systems into modern applications.
We rebuild aging software for cities, counties and agencies as modern applications that keep the same rules and the same records.
What the old system really does, linked to the exact source lines.
A new application on current frameworks that does the same job.
Records migrated from DB2, Oracle and more, with results matched before you switch.
The problem
Many important systems still run on software nobody fully understands anymore. The original developers have moved on, documentation is missing, and every change feels risky. Decades of records sit in databases that are expensive to license and hard to connect to anything new. Permitting, service requests, work orders, billing, utility accounts and in-house database tools are common examples.
Not just a report. A working modern system.
Documentation is where we start, not where we stop. The outcome is a new application your staff can use and your team can maintain, with the same rules, calculations and records as the system it replaces.
A COBOL batch program
Runs nightly on a mainframe. Reads meter readings from DB2, applies tiered water rates, senior discounts and late fees, and prints bills. Two people understand it, and changing a rate takes weeks.
A modern billing application
The same rates, discounts and fees as a tested service on a current framework, with a PostgreSQL database, web screens for staff, an API for other systems and rates staff can update. Every bill it produces matches the old program's output for the same inputs.
How we work
Inventory
We catalog the programs, languages, databases, files and integrations in an authorized copy of your system, and list what is missing.
Extract the rules
We document what the system actually does, such as how a fee is calculated or who can approve a record, linked to the exact source lines. Unknowns are listed, not guessed.
Design the replacement
We choose the target framework, database and hosting with your team, and agree the acceptance tests the new system must pass.
Build the modern equivalent
We build the new application one module or workflow at a time, using AI-assisted development reviewed by an engineer, while the old system keeps running.
Migrate the data
We extract, clean and transform records from legacy databases and files into the new database, and reconcile counts and totals so nothing is lost.
Prove it and switch over
The same inputs run through the old and new systems and the results are compared. Once they match, you cut over and receive the code, scripts, documentation and test results.
See it working
What makes this different
- Evidence first. Findings point to real source lines you can check yourself.
- Clear labels. We separate what the source shows, what software or AI tools suggest, what a reviewer approved, and what tests confirmed.
- Staged, not big-bang. Rewrites and migrations happen in fixed-scope stages with acceptance criteria, instead of one risky all-at-once switch.
- Your code stays yours. We work only on artifacts you authorize, under an agreed data-handling arrangement, and never run your code on shared systems without approval.
Security built in
Your code is read, never run on our servers. Your data stays in your environment. Every AI citation is checked against the real source, and AI use is disclosed in every proposal. Our software and engagements follow NIST guidance, including the Cybersecurity Framework, the Secure Software Development Framework and the AI Risk Management Framework. How we protect your systems.
Working with a prime contractor or agency? Relegacy is operated by CAPTIFIY LLC, an SBA-certified Veteran-Owned Small Business, and can support modernization work as a subcontractor or directly. Get in touch.