Some bank somewhere still runs card payments through COBOL older than the moon landing. Does it work? Kind of. That's the problem, nobody wants to be the one who breaks it. Ripping it out isn't cheap either. So who actually does this kind of work?

The Southwest Lesson

Old systems rarely crash with fireworks. Then Christmas 2022 comes, crew scheduling at Southwest falls over in the snow, and almost 17,000 flights get scrapped.

A few things push the topic up the agenda right now:

Licensing shocks, like the VMware price hikes after Broadcom's takeover

COBOL and PL/I specialists retiring, with few replacements coming

AI tools that need clean APIs and data, which old monoliths can't offer

Why not keep it in-house? Because internal IT is usually too busy patching what's already running. Modernization needs folks who've done it a few hundred times and won't be shocked when a batch job from 1998 turns out to feed payroll.

Outside firms also show up with their own tooling, from code scanners to AI helpers that chew through old code in days. Sounds expensive? It is. Running a failing system for five more years usually costs more.

Leading Application Modernization Companies to Know

To conclude, selection of the right application modernization company is crucial for enhancing business efficiency, security, scalability, and digital performance. Leading providers assist organizations to upgrade legacy systems to modern ones, integrate cloud technologies and streamline operations. 

To make a decision, compare the companies for their experience, industry knowledge, services and pricing. A partner who can help achieve long-term growth, innovation and sustainable business success is the right modernization partner. 

DXC Technology

DXC Technology mostly works with big, messy IT estates. Think airlines, insurers, defense contractors. The company says it moves around 65,000 workloads a year, and the full modernization lineup is laid out at website. Leonardo's UK unit brought DXC in to clean up core apps and pay down tech debt, and KION Group cut infrastructure costs by a quarter after moving SAP to Azure.

• Rehost, rearchitect, or migrate to SaaS.
• Compatible with AWS, Microsoft Azure, and Google Cloud.
• Recognized as a Mainframe Leader by ISG.

IBM

Hard to talk about mainframes without IBM. Loads of banks and airlines still run on IBM Z boxes, so that's where a bunch of projects kick off. The thing everyone asks about? watsonx Code Assistant for Z. You feed it COBOL, choose what to convert, and Java comes back still talking to CICS and Db2. The rest can sit tight for now.

• COBOL to Java, one service at a time
• Red Hat OpenShift for hybrid setups
• Good fit for firms keeping the mainframe

Capgemini

Capgemini is pretty vocal that AI should make modernization cheaper. In 2025 they launched a mainframe offer with AI agents that go hunting for rules buried in old code. One US life insurer tried it on product logic before switching policy systems. Forrester liked it enough to call Capgemini a Leader that year.

• Automated COBOL refactoring
• Strong insurance and automotive work
• Wider reach after acquiring WNS

Deloitte

Deloitte mixes consulting with serious engineering tools. Its innoWake suite converts COBOL, Natural and PL/I code and moves it to AWS largely on autopilot. Government work is where it shines: Wyoming's family services agency got off a 35-year-old mainframe in 16 months. It also built a gen AI front end for a United Airlines mainframe app.

• innoWake automated refactoring
• Deep government experience
• Close alliance with AWS

Kyndryl

Kyndryl is basically IBM's old infrastructure arm, spun off in 2021, so tons of mainframe work (and about 7,000 people who know it) ended up there. In August 2026 it launched Agentic Modernization. AI agents do the grunt work, people sign off, and it all runs through the Kyndryl Bridge platform. ISG named it a Leader this year too.

• Mainframe as a Service
• Kyndryl Bridge for visibility
• Cloud deals with AWS, Azure, Google

Accenture

Accenture has over 750,000 people on payroll. For legacy work it uses GenWizard, which basically writes the missing docs for old code, 70-something tech stacks of it. Sounds boring until you remember most old apps never had any. With AWS and Pega, Accenture also runs short sprints where clients see a prototype of the new app within weeks.

• GenWizard reverse engineering
• Joint mainframe offers with AWS
• Big SAP, Oracle and Workday practice

Tata Consultancy Services

TCS, part of India's Tata Group, relies on its own MasterCraft TransformPlus. Throw legacy code at it and the rules come out written down, plus microservices for the cloud. Even JCL batch jobs come back as Java Spring Batch (months of boring manual work, gone). Long programs, tight budgets: that's TCS territory.

• MasterCraft TransformPlus automation
• 4,000+ modernization engagements
• Strong banking and retail presence

So, Who Fits Whom?

There's no single winner here, whatever the sales decks say. Keeping the mainframe? Then IBM and Kyndryl probably land on your list. Lots of state agencies went with Deloitte, mostly for its AWS record. SAP plus two or three clouds, people call DXC, Accenture or Capgemini. TCS shows up on long programs where every dollar gets counted. Whoever it is, make them show a project like yours. Everything else is a slide deck.

Red Flags in Vendor Talks

Even a famous name can pitch a bad plan. Watch for:

No pilot or proof of concept before the big contract

Vague answers on who owns the converted code

A "big bang" cutover with no rollback plan

Promises that AI will do 100% of the work

No test plan comparing old and new outputs

Quick Comparison

Company	HQ	Signature Approach	Best For
DXC Technology	Ashburn, USA	Modernization factory, mainframe migration	Complex enterprise estates
IBM	Armonk, USA	watsonx Code Assistant for Z	Mainframe-centric firms
Capgemini	Paris, France	AI-driven mainframe refactoring	Insurance, automotive
Deloitte	London, UK	innoWake	Public sector
Kyndryl	New York, USA	Agentic Modernization, Kyndryl Bridge	Mainframe operations
Accenture	Dublin, Ireland	GenWizard	Large multi-platform programs
TCS	Mumbai, India	MasterCraft TransformPlus	Long, cost-sensitive programs

Final thought 

So, selecting the right company for application modernization services is crucial for boosting business performance, scalability, security, and operational efficiency. The top service providers can assist enterprises in modernizing outdated applications, transitioning to cloud, connecting with new solutions, and improving user experience. When choosing a partner, consider their technical knowledge, previous experience in the industry, services provided, costs, and reviews from customers.

 You can support growth and innovation in your organisation and stay competitive in the fast-changing digital world without compromising on your maintenance budgets, by partnering with the right modernization partner to streamline your operations and improve productivity. 

Frequently Asked Questions 

Q.1 What does application modernization actually mean? 

Ans. Getting old software onto current platforms. Could be a quick lift to the cloud. Could be a rewrite from scratch.

Q.2 How long are we talking?

Ans.  A few months for one app. Large mainframe programs often run two to four years.

Q.3 Why not just leave the old system alone? 

Ans. You can, for a while. Then the last COBOL guy retires, the license renewal lands, and something breaks on a Friday night.

Q.4 Does AI do the COBOL part solo?

Ans.  Not fully. It's quick at reading and converting code, but a human still has to test what comes out.

Q.5 Do small businesses face this too? 

Ans. Yes, on a smaller scale: an aging custom PHP site or an old on-premise CRM is the same problem.