Legacy software modernization and system replacement

Legacy modernization from ANTLR Tech is replacing the old system the business still runs on — in stages, with both running side by side, so nothing stops on the day you switch. It is built for your operation rather than configured from a product, so the screens follow the way your team already works. Typically 20–500 staff running something built a decade or more ago. It works, it's load-bearing, and every proposal to replace it has been shelved because the risk looked worse than the pain.

It depends on scope, integrations and how many locations you run — so we don't publish a number that would be wrong for most people. What we do commit to is the shape: a short paid discovery, then a fixed price for a defined first release that you approve before any production code is written. No open-ended billing, and no surprise at the end.

A first working release lands in 10–20 weeks from kickoff. We run two-week cycles with a demo at the end of each, so your team is using part of the system while the rest is still being built — rather than waiting for a single reveal at the end.

Companies depending daily on software nobody can safely change. Typically 20–500 staff running something built a decade or more ago. It works, it's load-bearing, and every proposal to replace it has been shelved because the risk looked worse than the pain. If an off-the-shelf product already fits without workarounds, we will say so — custom software only pays when the process is specific enough that rented tools fight you.

No, and you shouldn't. We move module by module with both systems running in parallel, so each step is small enough to reverse.

It moves with you. Records are mapped, cleaned, loaded and verified, and anything not migrated is archived in a format you can still read.

It's the normal starting point. We recover the rules from the code and from the people working around it, and document them before replacing anything.

Typically a few weeks per module. We stop the parallel run once the outputs agree and the team is confident, not on a fixed date.

You do. The repository, the hosting accounts and the data are yours from day one, documented at handover so another team could pick the work up. There is no seat licence and no fee that exists only to keep you with us.

No. Most clients arrive with a problem rather than a spec. Deciding what to build first — and what to leave alone — is the work of the discovery stage, and you keep the process map that comes out of it either way.