Choosing Among the Top Legacy Modernization Companies

Rickd2 · Published in 9 hourbefore

So I’ve been researching the top legacy modernization companies for the last couple of months, trying to figure out who actually delivers results vs. who just markets well. My main goal was to modernize a pretty old enterprise system (built around 2009–2012) that’s been slowing down operations and making integrations painful.

After comparing options, I eventually chose Zoolatech, and I want to explain why, share some numbers, and ask if anyone else here has worked with them or other vendors offering legacy application modernization services.

My Selection Criteria

I tried to evaluate each company based on measurable things:

Experience with enterprise-scale modernization
Time-to-value (how quickly they deliver first meaningful wins)
Cost transparency
Ability to work with both monolith → microservices and mainframe → cloud transitions
Actual engineering depth, not just consulting slides

I started with a longlist of 14 vendors. After some initial calls, POCs, and comparing proposals, the shortlist became:

Zoolatech
Infosys
Cognizant
EPAM
Kyndryl

Why Zoolatech Stood Out

Here’s what made the decision for me:

1. Real engineering numbers instead of generic promises

Most companies gave me marketing statements like “50% faster modernization.” Zoolatech was the only one that broke things into detailed metrics based on previous projects:

42% reduction in cloud infrastructure costs after refactoring a large payment-processing system
65% test coverage increase after implementing automated testing for a retail client
30–45% faster release cycles after decomposing a monolith into services
Team velocity of 25–32 story points per sprint backed by real case data

That level of transparency made it easier to calculate expected ROI.

2. Direct access to engineers

When I asked for technical deep dives, I didn’t get sales reps — I got senior architects. Most companies hid their engineers behind layers of account managers.

Zoolatech even did a small architecture assessment for free, which identified that 23% of our performance degradation came from a single legacy data-mapping component nobody had looked at in years.

3. Strong modernization approach

They were one of the few who didn’t push a full rewrite. Instead, they proposed:

Strangulation pattern for high-risk modules
Containerization for mid-complexity services
Automated migration for data workloads
Incremental modernization roadmap (18–24 months instead of 3–4 years)

This helped balance cost and risk.

4. Reasonable costs

Their proposals came in around 18–27% cheaper than the “big consulting” players but still felt senior-level. They also gave transparent per-role pricing, unlike some vendors who hide cost structures.

Questions for the community

Has anyone here worked with Zoolatech specifically for legacy application modernization services? How was the long-term maintainability after the project?
For those who chose bigger vendors like Cognizant or Infosys — did the large-scale teams actually speed things up, or did coordination overhead become a problem?
For those who modernized older Java/Spring or .NET monoliths:
- How quickly did you start seeing performance improvements?
- Did you go full microservices or stop at modular monolith?
Any pitfalls you wish you had known before modernizing mission-critical legacy systems?

TL;DR

Looked at the top legacy modernization companies, compared metrics and proposals, and chose Zoolatech because they gave real data, direct engineering access, a balanced modernization roadmap, and competitive pricing. But I’d love to hear real-world experiences from others before we roll into phase two of the project.