Digital Transformation

Legacy System Modernization for Data, Cloud and AI

Reports that don't match. Integrations that take months. AI pilots that stall at the data. We modernize the systems behind them in phases, starting with a two-week discovery, while the business keeps running.

Book a Legacy Discovery →Talk to an engineer first →

Technology partners:

  • AWS
  • Microsoft
  • Databricks
  • Snowflake
  • Salesforce

What Is Legacy System Modernization?

Legacy system modernization is the process of updating or replacing aging software, databases and infrastructure so they can be maintained, secured, integrated and scaled again. It ranges from moving a system unchanged, to restructuring it, to retiring it. Most programs mix approaches, and leave some systems alone.

Where Does Your Legacy Problem Show Up?

  • Nobody trusts the numbers.

    Data is pulled by hand from systems that were never built to share it, so every AI idea turns into a data problem.

    We move legacy sources onto one governed platform and run old and new side by side until the numbers match.

    Map my data sources

  • The AI plan depends on systems nobody wants to touch.

    Core systems are costly to change and risky to replace, and a failed modernization would be worse than none.

    In two weeks we show which systems block your plans, which can be opened up with an API instead, and which to leave alone.

    Get a prioritized plan

  • The legacy stack slows every release.

    Aging COBOL or Java, a single-server app, or code only one person understands. Every change carries risk.

    We modernize code alongside your team, using AI-assisted engineering to work through unfamiliar code faster.

    Talk to an engineer

When Does a Legacy System Need Modernizing?

Age alone isn't the reason. These are:

  1. 1.Reports from different systems don't agree
  2. 2.Data comes out through manual exports, not a feed or API
  3. 3.Every new integration is a custom build
  4. 4.Only one or two people understand the code
  5. 5.It can't be patched safely, or vendor support is ending

Which Modernization Approach Is Right for Your System?

Choose by what the system needs to do next, not by how old it is.

OptionWhat it meansChoose it when
Leave it (retain)No change for nowIt's stable, supported and not blocking anything
Open it up (API layer)Add APIs around a sound systemNew apps or AI need to reach it, but the core works
Move it (rehost, replatform)New infrastructure or runtime, little code changeThe hardware or hosting is the problem
Restructure it (refactor, re-architect)Rework the code or architectureThe design blocks scaling, integration or change
Replace or retire it (rebuild, replace, retire)New build, off-the-shelf software, or switch offIt's a commodity function, a dead end, or no longer used

Why Modernize Legacy Systems for AI?

AI can only use what it can reach. Most legacy systems were built for people and overnight batches, not for models and agents.

  • Data it can read

    Legacy blocker

    Batch exports, siloed databases

    The fix

    A governed modern data platform

  • Actions it can take

    Legacy blocker

    Logic trapped behind screens, no APIs

    The fix

    An API layer, then re-architecture if needed

  • Reliable response at volume

    Legacy blocker

    Single server, fixed capacity

    The fix

    Scalable cloud infrastructure

Often the fastest route isn't a migration. Opening up a sound core system through APIs can unblock an AI initiative sooner, and leaves the bigger decision for when you have evidence.

How Does a Legacy Modernization Project Work?

  1. 01

    Discovery

    2 weeks

    Map systems, dependencies, data flows and business rules. Score each system on criticality, change frequency and risk.

    You get

    • • A system map
    • • A risk register
    • • A recommended approach for each system (including which to leave alone)
    • • A leadership readout
  2. 02

    Plan

    Sequence the work by value and risk.

    You get

    A phased plan and implementation scope.

  3. 03

    Prove, then phase

    Modernize one slice in production first. Then run old and new in parallel, move users across in stages, and reconcile results, with a rollback path for every phase.

    You get

    Working releases while the business keeps running.

  4. 04

    Handover

    Documentation and knowledge transfer throughout.

    You get

    Your team owns and runs the system.

What Can AI Actually Do in Legacy Modernization?

Our engineers use AI coding assistants, including Cursor and Claude, to read unfamiliar code, document business rules, draft tests and produce first-pass changes. We used AI-assisted engineering to migrate a financial services firm's COBOL code to Java. Every change is reviewed, tested and owned by an engineer.

AI speeds upEngineers still own
Code understandingReading and summarizing legacy codeConfirming what behavior the business depends on
Business rulesDocumenting business rulesValidating rules with the people who use the system
TestingGenerating tests from existing behaviorDeciding and signing off what "equivalent" means
Code modernizationFirst-pass code translationArchitecture, security and performance under real load

Modernization proof

Legacy Systems We've Modernized

John WaterhouseFounder and CEO

Cloud Titans Ltd

xLoop architects meticulously planned and executed the migration, ensuring minimal disruption to our operations.

  1. Client
    A financial services firm
    What we did
    Modernized RPG applications, migrated COBOL code to Java using AI-assisted engineering, and moved applications and data to private cloud
    Outcome
    Completed with minimal operational disruption

  2. Client
    A leading South African retailer
    What we did
    Brought data from every source into a single governed platform
    Outcome
    Reporting, analysis, data science and AI now run from one trusted source

  3. Client
    One of Pakistan's leading NGOs
    What we did
    Migrated and modernized a national immunization platform and scaled its data infrastructure
    Outcome
    Over a billion immunization records for 4,000+ frontline health workers, on a foundation it can keep building on

  4. Client
    A leading Middle East retail and real estate group
    What we did
    Mapped every application, workload and data dependency, built a total-cost-of-ownership model and sequenced the move into migration waves, jointly with Microsoft
    Outcome
    A migration plan the business can fund and run in controlled waves

  5. Client
    A water utility
    What we did
    Traced slowdowns to root causes in existing code and re-engineered it, without replacing the platform
    Outcome
    Dependable data for operational decisions, from the platform the utility already owned

We've also migrated single-server ecommerce applications to AWS, upgraded PHP applications and run cloud-to-cloud migrations.

Legacy System Modernization at a Glance

Who it's forHeads of data, CIOs, CTOs and engineering leaders at mid-size and large organizations
Common triggersVendor support ending · data-center exit · AI or analytics blocked · integration backlog · audit findings · maintenance cost
Where to startTwo-week Legacy Modernization Discovery
ApproachesRetain · API layer · Rehost · Replatform · Refactor · Re-architect · Rebuild · Replace · Retire
Delivered from → toCOBOL → Java · RPG → private cloud · Java 8 → modern Java · SAP ERP/BW → Snowflake · single server → AWS · PHP upgrades · cloud-to-cloud
AI in deliveryCursor and Claude, with every change reviewed by an engineer
Engagement modelsScope-based project · embedded specialists · retainer advisory
Technology partnersAWS · Microsoft · Snowflake · Databricks · Salesforce
IndustriesFinancial services · Retail · Healthcare · Energy and utilities · Transport and logistics
OfficesKarachi · San Mateo · Dubai · Doha
Not a fitLarge mainframe replacement programs · systems that are stable and blocking nothing (we'll say so)

Legacy System Modernization FAQ

  • By never switching everything over at once. Old and new systems run in parallel, users or transactions move across in stages, results are reconciled between the two, and every phase has a rollback path. Short, scheduled cutover windows may still be needed. An all-at-once switchover isn't.

  • It starts with a two-week discovery. Rehosting a well-understood application can then take weeks. Re-architecting a core system many processes depend on can take a year or more, delivered in phases that each produce something usable. Discovery gives you the timeline for your own systems before you commit.

  • Five things drive it: codebase size and complexity, how well it's documented, the approach chosen for each system, how much data has to move, and how long parallel running needs to last. A credible estimate comes after discovery, not before it.

  • Only the parts the AI needs to reach. If a legacy system blocks the data an AI needs, or the actions an agent needs to take, fix that first, often with an API layer. If it doesn't, start the AI work now.

  • That's the normal case. We rebuild an understanding of the system from its code, its data and how people use it, document the business rules that matter, and confirm them with users before anything changes.

  • Partly. AI speeds up reading, documenting, testing and first-pass translation, and we used it to migrate COBOL to Java. It doesn't prove the new system behaves like the old one, so engineers still review, test and own every change. Whether AI tools are used on your codebase is agreed with you before work starts.

  • The ones that are stable, supported, rarely changed and not blocking anything. If a sound system is simply hard to reach, add an API layer and leave the core alone. If an assessment recommends modernizing everything, question it.

  • We set data classification, access controls and reconciliation checks before the first transfer, and keep both environments under the same controls during parallel running. For regulated data, our certified ISO 27001 and ISO 42001 Lead Auditors are part of the engagement.

Start With the Systems That Are Actually in the Way

Tell us what you're running and what it's blocking. In two weeks, you'll know what to modernize, what to open up with an API, and what to leave alone.

Book a Legacy DiscoveryTalk to an engineer first

Tell us about the system.

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