DCT

Modernize legacy technology for what is coming next.

Businesses are struggling with the cost and complexity of legacy technology while keeping operations running and preparing for AI. Our work maps what your systems actually do, removes technical debt, modernizes applications a piece at a time, and proves the result before anything cuts over.

Challenges & Solutions

The problems technology leaders describe, and what we do about each.

Legacy technology rarely fails outright. It falls out of support, gets slower to change, grows more expensive to run and more dependent on a small number of people, until the systems that once gave the business an advantage become the reason it cannot move. These are the five we hear most often.

  • 01

    The stack is several versions behind

    Angular 11, .NET Framework, Java 8, Node 14, every year of deferral makes the upgrade larger and harder to defend.

    What DCT does

    Moves you onto a current stack, with AI handling the conversion volume and writing the tests that prove nothing broke.

  • 02

    A small change takes months

    A week of work turns into a quarter, most of it spent finding out what breaks.

    What DCT does

    Reads code and production traffic together to map what the system actually does, cutting flow-tracing from days to hours.

  • 03

    Only a few people understand how it works

    Critical business rules sit with a handful of people who are hard to replace.

    What DCT does

    Turns what they know into a written spec and automated test suite in your version control, so new engineers start from that, not from whoever's free.

  • 04

    Most of the budget goes on keeping things running

    Maintenance and workarounds absorb most of the spend, leaving little for real change.

    What DCT does

    Scores every system on run cost and effort, then publishes the sequence with evidence, retention included where it's the right call.

  • 05

    New initiatives stall on the systems underneath

    AI and product initiatives depend on data the old applications were never built to expose.

    What DCT does

    Modernizes what they depend on without pausing operations, running new components alongside the old on live traffic until both agree.

How We Work

Your systems keep running while we modernize them.

Five stages, one piece at a time. The old system keeps serving customers while the new one is proven beside it.

  • 01

    Read

    Work out what the system does from the code and the traffic it serves, so AI reads and writes down the behaviour while you sign off on what the write-up got wrong.

  • 02

    Rank

    Decide what moves and in what order, so AI sizes run cost, dependency risk and effort for every candidate while you set the target architecture and sequence.

  • 03

    Rebuild

    Replace one piece at a time behind the interfaces the business already uses, so AI captures the old behaviour as tests and writes code that satisfies them while you own every design decision.

  • 04

    Run in parallel

    Send real traffic to both paths and compare the answers, so AI runs the comparison continuously and reports where they differ while you decide when to cut over.

  • 05

    Keep going

    Treat modernization as maintenance rather than a programme, so AI watches for new debt, drift and cost signals while you decide what's worth acting on now.

Case Studies

Two programmes that happened because they became affordable.

  • Media & entertainment · Sports streaming

    Billing rebuilt underneath paying customers

    Subscriptions ran on legacy in-app purchases across four app stores, each with its own receipt rules. Sign-in predated the way customers now sign in. All of it had to change on a platform with live subscribers, where no migration could disturb an existing customer and no renewal in flight could be lost.

    Building the new platform was never the hard part. Finding every path a purchase, renewal, entitlement check or cancellation could take - before touching any of them - was. AI traced the order and payment flows across the backend first, and that trace became the plan. Each migration case, including a store subscription that had silently stopped charging, was written as its own tested path while the old flows kept running alongside.

    • 80%

      faster analysis of legacy code

    • 75%

      less production code effort

    • Five

      workstreams running at once

    Billing moved with no subscriber-facing incident. Tracing a production flow went from several days to a few hours, five workstreams ran at the same time without the usual drop in quality, and old payment methods were tagged rather than deleted so both billing systems could coexist instead of splitting the customer base.

  • Financial technology · Rental housing access

    A 5,000-hour roadmap delivered inside a budget that could not stretch

    The estimate came back at more than 5,000 engineering hours across four concurrent workstreams - well outside budget. Adding people raised cost. Cutting scope shipped a weaker product into a market where the product is the position. Neither lever was acceptable.

    DCT applied AI across the whole lifecycle rather than only at code generation: reading requirements straight from the issue tracker, generating tests with each change, reviewing every difference before an engineer opened it, and drafting documentation beside the code. The roadmap shipped without changing the scope or the size of the team.

    • 40%

      less engineering effort

    • 40%+

      cost vs. estimate

    • 100%

      standards adherence

    On time, in budget, with no trade. Scope intact, team size unchanged, and every tool provisioned under client-owned accounts so intellectual property never left the client's boundary.

Common questions

Common Questions

DCT's modernization engagements run inside your team, on your repositories, under your accounts. These are the questions that come up before anyone signs anything.

What does DCT's modernization service include?

We read your systems and write down what they do, rank what should change and in what order, rebuild the parts worth rebuilding a piece at a time, and run the old and new together until the behaviour matches. Scope is set by what moves an operational or commercial number, not by a mandate to replace everything.

The first engagement produces three things you keep: a dependency map, a written specification of how the systems in scope actually behave, and a ranked sequence with the evidence attached.

Where does AI actually help and where does it not?

It helps most where the work used to be slow and unrewarding: reading a codebase nobody fully understands, reconstructing what a decade of undocumented behaviour does, writing the specification, generating the tests, and comparing the new path against the old one. On one live programme, that took tracing a production flow from several days to a few hours.

It does not choose your architecture. The only material a model has is the system you are trying to leave, so it can describe that system precisely and tell you nothing about what should replace it. That is why unguided code-to-code translation produces a modern-looking copy of the same problem.

How do you know the new system behaves like the one it replaced?

Because proving it is the deliverable, not the last phase. Before a piece is rebuilt, the behaviour of the existing path is captured as tests, edge cases included, and the replacement has to satisfy them.

Then both paths run on the same real traffic and the answers are compared until they agree. Cutover is a decision someone makes after reading the differences. A comparison you can read is what separates modernization from a rewrite you hope works.

Do we need to replace our legacy systems?

No, and often you should not. Replacement is one option among retaining, stabilizing, integrating, replatforming, refactoring and retiring, chosen on technical risk, what the business depends on it for, and what else it is wired into.

Cheap analysis makes this a better decision rather than a bigger programme. It is now affordable to find out that a twenty-year-old system is doing its job and should be left alone.

How do you decide what to change first?

From the dependency map, not from age or from who complains loudest. Work is ranked on operational risk, what the business depends on, run cost, effort and the order connected systems allow.

The ranking ships with the evidence behind each position, so your architects can argue with it. That argument is usually where the sequence gets better.

Does AI-generated code reach production without review?

No. A person approves every change, and that limit is enforced in the repository through branch protection and automated gates rather than written into a policy.

What changes is where engineering attention goes. Instead of reading every line of a generated difference, engineers review the intent, the plan, the comparison results and whatever the tooling flagged as risky.

Can this happen without disrupting operations?

That is the point of rebuilding a piece at a time behind the interfaces the rest of the business already uses. The existing path keeps serving customers while the new one is validated next to it, and anything that goes wrong is reversed by routing traffic back.

On a subscription platform rebuilt while it kept charging customers, billing moved with no subscriber-facing incident because every migration case existed as a tested path before release.

What happens to our integrations and data?

They are in scope from the first day. Interfaces, data flows, batch schedules and the operational processes around them are usually where the real risk sits, and they are the first things an undocumented system hides.

Treating this as an application-only exercise is the most common way a modernization programme discovers a problem too late.

Where does our source code go, and is it used to train anything?

Tooling runs under client-owned accounts inside your own cloud boundary. Your code and your data do not pass through a DCT environment and are not used to train models.

Everything the work produces - the map, the specification, the tests, the code - stays in your version control and remains yours if the engagement ends.

Are you going to move us onto a particular cloud?

Only where the evidence supports it. Most modernization tooling is built by platform vendors whose definition of success is your workload landing on their platform, which quietly turns an engineering decision into a procurement one.

We recommend the target from the dependency map, the run cost and the operational constraints. That includes hybrid, and it includes staying where you are.

Start with an assessment, not a roadmap.

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