Legacy Modernization

Move off the system nobody wants to touch — with the business rules proven, not guessed.

Timeline
Archaeology in weeks; migration priced per slice
Engagement
Fixed-fee discovery, then fixed scope per slice
Built for
A revenue-critical system on unsupported technology

The problem

The people who wrote it are gone. The documentation is a lie. Every quote you have had assumes a full rewrite and a two-year runway.

Morgan Stanley's internal tool read nine million lines of legacy code and saved an estimated 280,000 developer hours by turning it into plain-English specs. That is the part AI genuinely changed.
Morgan Stanley DevGen.AI, 2025

Who this is for

  • A revenue-critical system on unsupported technology
  • Undocumented, with the original authors long gone
  • Where a big-bang rewrite has already been tried or priced and rejected

Who this is not for

  • A rewrite you have already scoped and simply want staffed
  • Systems you intend to decommission within the year

How it runs

  1. 01

    Archaeology

    AI-accelerated code reading produces a dependency and data-flow map and extracts the business rules into plain language.

  2. 02

    Rule verification

    Every extracted rule is confirmed against production behaviour by a person. This is the step that decides whether the project succeeds.

  3. 03

    Equivalence harness

    Golden tests built from real traffic, in place before a single line moves.

  4. 04

    Strangler migration

    Slice by slice, reversible at every step, running in production the whole way.

  5. 05

    Decommission

    The old system goes dark only once nothing depends on it, provably.

What you get

  • System and dependency map
  • Verified business-rule catalogue in plain language
  • Behaviour-equivalence test suite built from real traffic
  • Reversible slice-by-slice migration plan
  • Runbooks and handover documentation

Legacy Modernization: questions we get asked

How do you modernize a system nobody understands any more?

You reconstruct the business rules before you touch the code. AI reads the legacy source and drafts plain-language specifications; your team then verifies each rule against real production behaviour. Only verified rules become requirements for the new system.

Is it safer to rewrite or to migrate incrementally?

Incrementally, in almost every case. A strangler migration keeps the system in production throughout and stays reversible at every slice, so a bad step costs days rather than the whole programme.

How do you prove the new system behaves like the old one?

With a behaviour-equivalence harness built from real production traffic before any code moves. Old and new run against the same inputs and any divergence is a failing test, not a support ticket discovered months later.

What does legacy modernization cost, and how is it priced?

The archaeology phase is a fixed fee, so you can stop after it with a map and a plan and owe nothing further. Migration is then priced per slice, which keeps scope and risk bounded at every stage.

Delivered in your region.

  • GDPR
  • UAE PDPL
  • ISO 27001 practices
  • Data residency in the EU, the UAE, or your own cloud account

APPINE L.L.C-FZ, Dubai

$ appine assess --fixed-fee

Two weeks. Fixed fee. You end with a decision, not a deck.

A system and codebase audit, a risk register ranked by severity, an engineering baseline, and an explicit recommendation — keep, harden, rebuild, or don't do it at all.

If the answer is “don't hire us,” we'll write that down too.

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