Company lists · Data refreshed November 2026

Top 24 Legacy system integration developers based in the United States

RevenueBase identified 1,448 company matches for legacy system integration developers associated with the United States as of November 2026 and tracks 81,050 professional contacts across them, including 20,602 with verified work emails. New York is the largest hub.

This list covers company matches for legacy system integration developers associated with the United States, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 6, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list RevenueBase SmartSearch · Exact Recorded Nov 6, 2026 How this list was built
1,448Companies
81,050Contacts tracked
20,602Verified emails
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The 24 largest legacy system integration developers based in the United States

Ranked by team size
Top 24 of 1,448 company matches for legacy system integration developers based in the United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 6, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchDowners Grove, IL, United StatesHQ recorded Nov 6, 20261,001-5,0003,542 contacts →

Exact match

“Ensono is an expert technology adviser and managed service provider.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
2Exact matchConshohocken, PA, United StatesHQ recorded Nov 6, 20261,001-5,0002,725 contacts →

Exact match

“Connect everything to achieve anything™ #TeamBoomi”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
3Exact matchBoston, NY, United StatesHQ recorded Nov 6, 20261,001-5,000889 contacts →

Exact match

“Tanisha Systems, founded in 2002 in Massachusetts-USA, is a leading provider of Custom Application Development and end-to-end IT Services to clients globally.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
4Exact matchRockford, IL, United StatesHQ recorded Nov 6, 2026501-1,000550 contacts →

Exact match

“Cleo is a supply chain orchestration software company that connects, automates, and optimizes the critical processes that keep goods and data moving.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
5Exact matchSalt Lake City, UT, United StatesHQ recorded Nov 6, 202651-200543 contacts →

Exact match

“Your Business Technology Partner.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
6Exact matchMiami, FL, United StatesHQ recorded Nov 6, 2026501-1,000493 contacts →

Exact match

“Zoolatech is a global software engineering partner helping enterprises modernize legacy systems, adopt AI, and build scalable digital platforms.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
7Exact matchSan Diego, GA, United StatesHQ recorded Nov 6, 2026201-500480 contacts →

Exact match

“Our Mission: TIG will earn its place as a trusted partner to our clients, providing only the highest level of service, value and advanced technology to power their strategic…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
8Exact matchSt. Louis, MO, United StatesHQ recorded Nov 6, 2026201-500448 contacts →

Exact match

“We engineer the systems that power your business.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
9Exact matchPlano, TX, United StatesHQ recorded Nov 6, 2026501-1,000432 contacts →

Exact match

“When we look at the way enterprises operate today, we see a fundamental challenge.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
10Exact matchPleasanton, FL, United StatesHQ recorded Nov 6, 2026201-500386 contacts →

Exact match

“At United Techno, we harness experience and collaboration to address customer challenges and devise intuitive solutions.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
11Exact matchMclean, VA, United StatesHQ recorded Nov 6, 2026201-500372 contacts →

Exact match

“Groundswell is a specialized, highly agile systems integrator delivering advanced technology solutions as a trusted mission partner to federal agencies.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
12Exact matchChaska, MN, United StatesHQ recorded Nov 6, 2026201-500345 contacts →

Exact match

“As a partner to some of the world’s largest companies, Bailiwick provides professionally managed technology integration and IT expertise for complex, large-scale IT initiatives.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
13Exact matchHouston, TX, United StatesHQ recorded Nov 6, 2026201-500336 contacts →

Exact match

“SiRA Consulting is a Certified MBE consulting company that was founded in 2012.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
14Exact matchSomerset, NJ, United StatesHQ recorded Nov 6, 2026501-1,000306 contacts →

Exact match

“Natsoft was established in the year 2004 with an intent to provide Software Development and System Integration Services.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
15Exact matchSeattle, WA, United StatesHQ recorded Nov 6, 20261,001-5,000303 contacts →

Exact match

“Blackstone eIT is a leading System Integrator (SI) and Independent Software Vendor (ISV), globally dedicated to engineering transformative enterprise solutions and intelligent…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
16Exact matchNew York, NY, United StatesHQ recorded Nov 6, 2026201-500295 contacts →

Exact match

“Award-winning NetSuite and Stripe partner.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
17Exact matchEdison, NJ, United StatesHQ recorded Nov 6, 2026201-500272 contacts →

Exact match

“At Nalashaa Solutions, we’re not just technologists; we’re your trusted partners in transformation.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
18Exact matchFalls Church, VA, United StatesHQ recorded Nov 6, 2026501-1,000230 contacts →

Exact match

“Fortitude Systems provides your business with the horsepower to get the job done to drive your IT process faster and more efficiently.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
19Exact matchSan Jose, IL, United StatesHQ recorded Nov 6, 20261,001-5,000226 contacts →

Exact match

“Infobahn specializes in full-lifecycle project and consulting efforts conducted in strategic partnership with some of the world's most prominent companies.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
20Exact matchDenver, CO, United StatesHQ recorded Nov 6, 202651-200223 contacts →

Exact match

“Pulse Software Solutions is a Denver-based custom software development firm with a proud history of building internet-based systems since 1998.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
21Exact matchMclean, AL, United StatesHQ recorded Nov 6, 20261,001-5,000221 contacts →

Exact match

“Headquartered in McLean, Va, B&A is a leading information technology systems integrator providing solutions through the following service offerings: Modernization &…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
22Exact matchBellevue, WA, United StatesHQ recorded Nov 6, 2026201-500214 contacts →

Exact match

“Founded in 1994, Congruent Software is a leading software development outsourcing company specialized in custom applications development, enterprise software, cloud computing, and…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
23Exact matchWashington, VA, United StatesHQ recorded Nov 6, 202651-200210 contacts →

Exact match

“We collaborate closely with technology and business leaders across industries to help drive organizational advancement through AI-powered, purpose-built software solutions.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
24Exact matchSt. Louis, MO, United StatesHQ recorded Nov 6, 2026201-500208 contacts →

Exact match

“Astadia is the industry leader for mainframe migrations and modernizations.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase

Showing 24 of 1,448 legacy system integration developers based in the United States

See the full list, filter by size, metro and specialty, and access 20,602 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Legacy system integration developers based in the United States at a glance

As of Nov 6, 2026
25.4%Verified-email coverage
56.0Average contacts per company
11-50Median size (employees)
3.5%Largest-city concentration · New York
Nov 6, 2026Page data refreshed

Companies by employee count

1-10
673
11-50
449
51-200
235
201-500
48
501-1,000
17
1,001-5,000
19
10001+
4

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 1,448 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Company records associated with the United States whose business descriptions match “legacy system integration developers” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every displayed company carries at least one verified work email. RevenueBase tracks 20,602 professional contacts with verified work emails across the full matched dataset. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on November 6, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “legacy system integration developers”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many legacy system integration developers are there based in the United States?

RevenueBase identified 1,448 company matches for legacy system integration developers associated with the United States as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Ensono tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most legacy system integration developers?

New York leads with 50 company records, followed by Houston (35) and Austin (31).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 20,602 professional contacts with verified work emails tracked across these 1,448 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 6, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.