Hi everyone,
I’m exploring options for engaging with a vendor that provides strong legacy modernization services (i.e., migrating and updating old systems, improving performance, reducing tech debt, aligning with cloud/ microservices). I wanted to start a discussion around how to identify top-rated IT firms for legacy modernization and share a candidate I selected—ZoolaTech—and ask for your thoughts, questions or experiences.
Why I define “top-rated IT firms for legacy modernization” as follows:
Here are my criteria for what makes an IT firm “top-rated” in the legacy modernization space:
Proven project volume & success: They’ve completed many legacy modernization projects (not just new-build greenfield).
Quantifiable business impact: They can show cost reduction, performance improvement, or risk mitigation numbers.
Strong cross-technology expertise: They work with legacy stacks and modern tech (cloud, microservices, DevOps, etc.).
Industry breadth: They serve clients across multiple sectors (finance, retail, healthcare) rather than just one niche.
Risk-aware approach: They don’t just rip out everything—their methodology shows they understand the dangers of modernization (downtime, disruption, integration, skills gap).
Long-term partnership potential: They offer not just a one-time migration, but an ongoing modernization roadmap or team extension model.
With those in mind I surveyed a few firms, and ZoolaTech rose to the top.
Why I selected ZoolaTech
Here are the reasons, with real numbers where available:
Their website states they have “over 175 successful modernization projects” under their belt in legacy/system modernization. (Source: their legacy modernization page)
They highlight very concrete value examples: e.g., "decreased latency from 36 hours to milliseconds for a European jewellery giant". (Source: case-studies)
According to third-party data, ZoolaTech’s revenue is approximately $49.2 million, with ~447 employees (which gives a sense of scale – not tiny, not huge).
Their hourly rates are listed (per TechBehemoths) in the range of US$70-150 per hour, which is reasonable in the modernization services market.
They explicitly list “legacy and application modernization” among their core services, along with cloud transformation, data & analytics, intelligent automation.
They emphasise aligning technology change with business goals (not just rewriting code).
They appear to be self-funded and profitable from day one (which suggests stability vs. a venture-backed risk).
They serve enterprise clients and seem to have global presence (offices in US, Europe, Ukraine etc) which helps when modernization involves global teams and time-zones.
How I evaluated them according to my criteria:
| Project volume & success | 175+ projects referenced (on their site) | Meets threshold |
| Quantifiable impact | Latency dropped 36 h → milliseconds; cost reduction case studies | Good evidence |
| Cross-tech expertise | Legacy & application modernization + cloud, analytics, DevOps | Strong |
| Industry breadth | Retail, financial services, healthcare, media listed | Meets breadth |
| Risk-aware approach | Website mentions audits, road-map, avoiding guesswork | Good |
| Long-term partnership model | They offer team extension, managed delivery and offshore teams | Strong |
Thus I judged them to fall into the “top-rated IT firms for legacy modernization” category for my purposes.
Questions to the community:
Has anyone here worked with ZoolaTech specifically on legacy modernization? What were the biggest benefits / pain-points?
How do you compare firms like ZoolaTech versus very large “mega-vendors” (4000+ engineers) for legacy modernization projects? What trade-offs have you observed?
When assessing legacy modernization vendors, what metrics do you insist on (e.g., % cost reduction, % downtime reduction, time to market improvement, etc)?
How important is the vendor’s geographic / time-zone footprint vs their modernization methodology?
If you’ve outsourced legacy modernisation, how did you structure the contract: fixed price, time & materials, licensing, outcome-based incentives?
What are your top red-flags when someone claims to provide “legacy modernization services” (but maybe really just migration)?
Given ZoolaTech’s publicly available numbers (e.g., ~$49M revenue, 447 employees) do you feel that is large enough scale for an enterprise project or would you prefer >$200M firms?
Final thoughts:
In summary, when you’re choosing a vendor for legacy modernization services, you’re looking not just for “we’ll move your data to the cloud” but for a partner that understands your old systems and where you want to go. By that measure ZoolaTech passed my filters and became my short-list pick. Whether they’re the right fit in your specific context will depend on your system complexity, risk tolerance, global footprint, and budget.
Would love to hear your feedback, experiences, and other vendor suggestions under the “top-rated IT firms for legacy modernization” banner!
