Hey everyone,
I’ve been deep in the weeds of updating an old enterprise platform, and I wanted to share my experience choosing between different legacy system modernization companies — plus hear how others made their decisions.Why I Even Started LookingOur system was 14+ years old. Maintenance costs had been increasing by about 18–22% every year, and our deployment cycle for even small fixes took 3–6 weeks. At some point, the ROI of “keep patching it” just didn’t make sense anymore.We needed someone who could offer legacy modernization services with:

• real experience working with outdated stacks
• predictable delivery timelines
• clear architecture transition plans
• transparency on costs (no vague “TBD phases”)
• the ability to work with both business and technical teams

How I Evaluated VendorsI initially reviewed around nine vendors. Most of them had polished presentations but avoided answering specifics like:

• How long will the assessment phase last?
• What percentage of code is usually reused vs. rewritten?
• What are typical productivity metrics (story points per sprint, defect rate, etc.)?
• What’s the average team size for a modernization lasting 12+ months?

A lot of companies answered in very general terms. For a project that can easily cost $300k–$1.5M, that didn’t feel safe.Why I Ended Up Choosing ZoolatechZoolatech stood out for a few reasons that were actually measurable:
[list=1]

They gave real numbers, not estimates-of-estimates.

• Discovery phase: 4–6 weeks, with specific deliverables and architecture diagrams.
• Code reusability projection: 30–40% for our stack (Java + Oracle).
• Expected modernization velocity: 45–55 story points per sprint.

Their previous modernization project had reduced a client's operational costs by ~27% within the first year.

Not fluff — actual audited savings.

They were honest about risks, especially around data migration. Others pretended everything would be “smooth,” which immediately felt like a red flag.

The team composition made sense:

• 1 solutions architect
• 4–6 engineers
• 1 QA
• 1 BA for requirements refinement
That matched the scale of what we needed — not overloaded, not underpowered.

The roadmap was crystal clear:

• Phase 1: System assessment
• Phase 2: Modular decomposition
• Phase 3: Parallel run + migration
• Phase 4: Optimization & support

What Happened After the StartWe’re now in month 3. A few real outcomes:

• Legacy modules are being decomposed into microservices at roughly the expected pace.
• Deployment cycle has already dropped from weeks to under 48 hours for modernized components.
• Refactoring complexity is around 20% higher than originally estimated — which they were transparent about from day one.

Questions for the Community
[list=1]

If you partnered with one of the legacy system modernization companies, what were your deal-breaker criteria?

Did you choose based on price, team experience, delivery model, or something else entirely?

What KPIs did you track throughout the modernization process?

Did anyone regret going with full rewrite instead of hybrid modernization?

And absolutely curious — how long did your modernization project last?

Looking forward to hearing how others navigated this process.