We don't ask you to trust the rewrite. We prove it.
TurkeyCode takes legacy systems frozen in time and turns them into modern software you can finally change, proving the new version behaves exactly like the old, bit by bit.
Nobody can prove the new system still does what the old one did.
The business logic lives in code no one fully understands, written by people who've left. So teams freeze on a system they can't safely touch, or gamble on a rewrite no one can verify.
Parity is the whole point.
We capture how your current system actually behaves, real inputs, real outputs, real data flows. We rebuild it on a modern stack. Then we replay your system's own behavior against the new one and prove they match, evidenced in a report you can audit.
Record the truth
We capture the legacy system's real behavior as ground truth, not documentation, not memory, the system itself.
Modernize
An AI build engine, artifact gates, automated QA at every step, rebuilds on your target stack, fast. It doesn't get a vote on whether it's right. That's step 3.
Prove parity
We replay your legacy system's real behavior against the new build, independently, case by case. A rebuild can pass its own tests and still be wrong; parity is what catches it.
“Done” isn't our opinion. It's a passing parity check, objective, automated, and yours to audit.
Migration also tells you what's broken.
A faithful rebuild reproduces the old system exactly, bugs and all. That's the contract: no silent “improvements” that quietly change what your business runs on. But we don't let the defects hide. Parity surfaces the legacy system's latent flaws, stale regulatory thresholds, silent rounding loss, missing audit records, and routes each one to a named owner for a signed decision. Faithful by default; changed only on the record.
Find the latent bugs
We flag known-wrong behavior the rebuild faithfully carried forward, outdated rules, truncation, dropped records, independent of any rewrite.
A person rules
Each flag goes to a named owner: reproduce it, fix it, or formally accept it. Never silently carried, never silently changed.
Signed & auditable
Every ruling is signed and logged. Each deliberate deviation from the legacy system is a decision on the record, not a surprise in production.
You don't just get a modern system. You get a signed account of every place the old one was wrong.
Start with one program. Scale on proof.
Parity Proof
Bring us one self-contained program. We modernize it and hand you a parity report proving it behaves identically. Proof on your code before any commitment.
Upload your program →Per-Program Migration
We modernize your platform program by program, each parity-verified, priced to the value of the outcome, a fraction of the rebuild alternative.
Continuous Change
Once modern, every new feature and fix flows through the same parity gates, automatically re-verified against your system's proven behavior, logged, and shipped without re-introducing risk.
Embedded Engineering
Hands-on delivery, remote or on-site, when you want us in the room alongside your team.
The engine is public. The method is auditable.
The AI build engine behind Turkey Enterprise is the public, MIT-licensed TurkeyCode engine. Inspect it, run it, self-host it, the same pipeline, pointed at legacy, with parity proof on top.
The free tool builds your weekend app. The same engine modernizes your 30-year-old platform.
TurkeyCode is an open-source AI build engine. At weekend scale it's a free CLI. At enterprise scale it's Turkey Enterprise, the same gated pipeline, pointed at legacy systems, with deterministic parity proof on top.
TurkeyCode CLI
Describe an app, build it, deploy it. Free, MIT-licensed, self-hostable. Where the engine, and the community, lives.
Parity-verified legacy migration
The enterprise pipeline: capture, rebuild, and prove behavioral equivalence on your production systems, with delivery and IP terms built for it.
Bring us one program. We'll prove it.
No commitment, no rip-and-replace. One self-contained program, modernized, with a parity report in your hands. Decide from there.