Core System Modernization

We replace or wrap the systems your business runs on, one domain at a time, with every cutover reconciled.
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Definition

What is core system modernization?

Core system modernization is the replacement or re-architecture of the systems of record a business cannot operate without: the policy and billing platform at an insurer, the core ledger at a bank, the ERP and order systems at a manufacturer or distributor, and the mainframe applications that still run many of them. BD Emerson decides with you which systems to replace, which to wrap behind APIs, and which to retire, then builds and converts one domain at a time. We deliver larger programs alongside our Andersen Consulting colleagues, including SPR's custom software and cloud modernization teams.

Most programs combine three moves. Wrapping puts a documented API layer and an event stream in front of a stable core, so new products and channels can change without touching it. Replacing builds or buys a new system and moves the business onto it in reconciled waves. Retiring shuts down what no longer earns its keep. The right mix depends on which constraint binds first: the vendor contract, the people who can still maintain the system, or the products the business cannot launch on it.

Clients usually arrive at a decision point: a license renewal inside three years, a mainframe contract that sets the exit date, a product launch the current system cannot support, or an acquisition that left two cores running the same business. The method is the same in insurance, banking, and enterprise systems, and it starts with a five-year cost model of every path, including staying where you are.

Services

What our core system modernization services include

Replace or wrap decision
API and event wrapping
Staged replacement
Data conversion
Mainframe and legacy code
Cutover and run

Replace or wrap decision

We inventory your systems of record, their contracts, their integrations, and the people who keep them running, then cost three paths over five years: keep and wrap, replace in stages, or replace at once. You get a written recommendation with the dates that drive it, including the cases where staying put wins.

API and event wrapping

Where the core stays, we put a documented API layer and an event stream in front of it, so channels, partners, and analytics read and write through stable contracts. New products then ship on your schedule, and the core can be replaced later on a planned date or kept.

Staged replacement

We replace one domain, product, or business line at a time. Each increment is built, loaded with converted data, run in parallel against the old system, and cut over on a planned date, so the program can pause after any increment and leave a working estate behind.

Data conversion

Conversion work starts in the first month. We profile the source data, map it to the target model, and run mock conversions until record counts, balances, and in-force values tie out, with every exception traced to a mapping rule or a data fix before the real cutover.

Mainframe and legacy code

Mainframe work runs with our Andersen Consulting colleagues, including SPR. We assess the batch schedule, the COBOL and PL/I programs, and the data stores, extract the business rules worth keeping, and choose per workload between rehosting, refactoring, and rebuilding, sequenced around the batch cycle and the contract exit.

Cutover and run

We rehearse each cutover, keep a tested rollback ready, and hand over the code, infrastructure, and runbooks with your engineers already working in them. After go-live your team can run the platform alone, or we stay on to run and extend it under a separate agreement.

Our approach

Map it, prove it, replace it, retire it

01

Map and model

We map the systems of record, the integrations, and the contract dates, then model the cost of each path over five years using your volumes and staffing. The recommendation names the decision date and what drives it.

02

Prove one increment

We build or wrap one bounded piece first, such as a product, a region, or a single integration, and run it on production data. Your team uses it before the full program is approved.

03

Replace in waves

Each wave moves a domain with its converted data, runs in parallel until the numbers match, and cuts over on a planned date. Waves are sized so that any one of them can be reversed.

04

Retire and hand over

We decommission each old system after its last wave closes, archive the records you must keep, and hand your team the code, infrastructure, and runbooks.

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Weighing a core system replacement?

Bring your system inventory and your contract dates. In one working session we will map what to replace, what to wrap, and what a first increment would prove.

Our Advantage

Why BD Emerson for core system modernization

Independent of the vendors

We resell no core software and take no vendor margin, so the replace, wrap, or stay recommendation rests on your numbers. When a suite or your current core is the better answer, we say so.

Security built in

The firm that builds your core also runs penetration testing, incident response, and compliance programs, so access controls, audit trails, and the evidence examiners ask for are designed in from the first sprint.

Andersen Consulting depth

BD Emerson is part of Andersen Consulting. Large programs draw on Andersen Consulting colleagues, including SPR's custom software and cloud modernization teams, under one plan and one accountable lead.

Reviews

What our customers say

Great consulting firms for scaling security, compliance, and appsec.

Outstanding partner in Technical and Cyber Due Diligence

Appsec maturity and application hardening.

BD Emerson helped us simplfiy our compliance management.

BD Emerson did such a phenomenal job. What started as privacy support quickly became a full partnership across compliance, engineering, and even business operations. They’re embedded with our team. They understand our product. They move fast. They’re simply invaluable.

Adam Ben Jacobs

CTO @ OneStep GPS

Great consulting firms for scaling security, compliance, and appsec.

Outstanding partner in Technical and Cyber Due Diligence

Appsec maturity and application hardening.

BD Emerson helped us simplfiy our compliance management.

BD Emerson did such a phenomenal job. What started as privacy support quickly became a full partnership across compliance, engineering, and even business operations. They’re embedded with our team. They understand our product. They move fast. They’re simply invaluable.

Adam Ben Jacobs

CTO @ OneStep GPS

We had a hard time finding the right company to partner with in support of our compliance journey. Some vendors sell the idea that they do the work, but then you end up doing everything. The ambiguity is what killed our last project. BD Emerson’s team has such great technical knowledge and understands the standard so well that they made us comfortable with moving fast. This has led to us closing major enterprise customers that were previously out of reach because of security and compliance.

Tom Watkins

CEO @ AMI AssetTrack

Lead an enterprise initiative to overhaul the organization's technology stack from ecommerce, corporate tech, and corporate security.

Supported ISO 42001 exercise and served as internal auditor.

Rubrik's privacy and compliance team began with the backbone of BD Emerson. BD Emerson supported building out the privacy program, GRC (ISO 27001, SOC 2, CMMC, FedRAMP), and the appsec function.

We needed a partner who could move quickly, without sacrificing precision. BD Emerson brought the expertise, structure, and speed we were looking for. Their team became an extension of ours, embedding themselves across the organization, guiding us step by step, and giving us confidence in areas we hadn’t tackled before. The internal audit they conducted was so detailed that even the external auditors called it out. Achieving ISO 27001 with zero nonconformities says everything you need to know about the quality of the partnership.

Walid Souilem

CTO @ FGI Worldwide

We had a hard time finding the right company to partner with in support of our compliance journey. Some vendors sell the idea that they do the work, but then you end up doing everything. The ambiguity is what killed our last project. BD Emerson’s team has such great technical knowledge and understands the standard so well that they made us comfortable with moving fast. This has led to us closing major enterprise customers that were previously out of reach because of security and compliance.

Tom Watkins

CEO @ AMI AssetTrack

Lead an enterprise initiative to overhaul the organization's technology stack from ecommerce, corporate tech, and corporate security.

Supported ISO 42001 exercise and served as internal auditor.

Rubrik's privacy and compliance team began with the backbone of BD Emerson. BD Emerson supported building out the privacy program, GRC (ISO 27001, SOC 2, CMMC, FedRAMP), and the appsec function.

We needed a partner who could move quickly, without sacrificing precision. BD Emerson brought the expertise, structure, and speed we were looking for. Their team became an extension of ours, embedding themselves across the organization, guiding us step by step, and giving us confidence in areas we hadn’t tackled before. The internal audit they conducted was so detailed that even the external auditors called it out. Achieving ISO 27001 with zero nonconformities says everything you need to know about the quality of the partnership.

Walid Souilem

CTO @ FGI Worldwide

BD Emerson didn’t just help us meet our compliance goals; they integrated security and privacy into the core of our operations. I highly recommend BD Emerson to anyone seeking SOC 2 or GDPR compliance, or simply looking to enhance their security team and boost customer trust in their product and services. Their dedication and expertise have been invaluable to our success.

Padraig Reilly

CEO, Boxcore

BD Emerson understood our business requirements and worked side-by-side with us. The policies and controls we developed together not only meet compliance standards but improve how we operate day to day.

Matt Meierdierks

IT Manager, Lincoln Industries

From day one, BD Emerson brought urgency, clarity, and a sharp understanding of what truly matters to our business — earning and keeping customer trust. They went beyond helping us meet compliance requirements; they helped build a foundation for secure, scalable growth. That kind of partnership is rare.

Jason Marker

CEO @ LifeLenz

BD Emerson didn’t just help us pass an audit—they helped us build a sustainable culture of security.

Alexey Indeev

CTO Spare

BD Emerson was essential in helping our company navigate the daunting process of leveling up our security infrastructure. BD Emerson’s impressive expertise and confidence throughout the process helped our team exceed HIPAA and SOC 2 Type 1 standards quickly, distilling what can be an overwhelming process into a streamlined, organized effort. From day one they began adding value and getting us on course. With their help we delivered on a massive security overhaul with both extreme efficiency and thorough attention to details. Because of BD Emerson’s support, we’ve increased our clients’ trust in Titan Intake and the life-changing work it accomplishes for those seeking specialist referrals.

Patrick Bruce

CEO, Titan Intake

BD Emerson didn’t just help us meet our compliance goals; they integrated security and privacy into the core of our operations. I highly recommend BD Emerson to anyone seeking SOC 2 or GDPR compliance, or simply looking to enhance their security team and boost customer trust in their product and services. Their dedication and expertise have been invaluable to our success.

Padraig Reilly

CEO, Boxcore

BD Emerson understood our business requirements and worked side-by-side with us. The policies and controls we developed together not only meet compliance standards but improve how we operate day to day.

Matt Meierdierks

IT Manager, Lincoln Industries

From day one, BD Emerson brought urgency, clarity, and a sharp understanding of what truly matters to our business — earning and keeping customer trust. They went beyond helping us meet compliance requirements; they helped build a foundation for secure, scalable growth. That kind of partnership is rare.

Jason Marker

CEO @ LifeLenz

BD Emerson didn’t just help us pass an audit—they helped us build a sustainable culture of security.

Alexey Indeev

CTO Spare

BD Emerson was essential in helping our company navigate the daunting process of leveling up our security infrastructure. BD Emerson’s impressive expertise and confidence throughout the process helped our team exceed HIPAA and SOC 2 Type 1 standards quickly, distilling what can be an overwhelming process into a streamlined, organized effort. From day one they began adding value and getting us on course. With their help we delivered on a massive security overhaul with both extreme efficiency and thorough attention to details. Because of BD Emerson’s support, we’ve increased our clients’ trust in Titan Intake and the life-changing work it accomplishes for those seeking specialist referrals.

Patrick Bruce

CEO, Titan Intake

Certificates

Our accreditations

Our practitioners hold security, privacy, cloud, and AI governance certifications, and the people who earned them do the work on your engagement.
FAQ

Frequently asked questions

What is the difference between core system modernization and application modernization?

Should we replace our core system or wrap it with APIs?

How long does core system modernization take?

What drives the cost of core system modernization?

How do you avoid a big-bang cutover?

Do you work on mainframe and COBOL systems?

Who owns the new system and the code?

Do you resell or implement core software suites?

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