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Company lists · Data refreshed September 2026

Top 25 Custom software agencies based in Seattle, United States

Compiled by the RevenueBase Data Team Data refreshed Sep 24, 2026 76 companies tracked

RevenueBase identified 76 custom software agencies headquartered in Seattle, United States as of September 2026 and tracks 557 professional contacts across them, including 139 with verified work emails. New York is the largest hub.

This list covers custom software agencies headquartered in Seattle, United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 24, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, 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 HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 24, 2026 86% judged on-target in blind review
76Companies
557Contacts tracked
139Verified emails
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The 25 largest custom software agencies based in Seattle, United States

Ranked by team size
Top 25 of 76 custom software agencies based in Seattle, United States, ranked by team size, largest first. Data refreshed Sep 24, 2026. RevenueBase Smart Search rates how each company's information relates to custom software agencies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1
White Rabbit Group
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 202651-200135 contacts →

Partial evidence

“White Rabbit Group is a software development agency with a highly diverse and creative team that takes an idea through development and into scale.”

Source: RevenueBase Database · checked Sep 24, 2026
2
Spiderbox Design Vietnam
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 202651-20038 contacts →

Indirect evidence

“Spiderbox Design - Transforming businesses worldwide with innovative digital solutions since 2011.”

Source: RevenueBase Database · checked Sep 24, 2026
3
Fast Track Team
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 202651-20028 contacts →

Indirect evidence

“Fast Track creates cutting edge websites and web applications for businesses of all sizes faster and better than anyone else in the business.”

Source: RevenueBase Database · checked Sep 24, 2026
4
Pubgenius INC
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-5025 contacts →

Partial evidence

“At pubGENIUS we build software that helps great ideas become real products.”

Source: RevenueBase Database · checked Sep 24, 2026
5
NEW Normal
Strong evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-5025 contacts →

Strong evidence

“NewNormal builds custom software and lasting partnerships Since 2012 we’ve helped clients turn ideas into products that scale.”

Source: RevenueBase Database · checked Sep 24, 2026
6
Dreamteam Mobile
Strong evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-5015 contacts →

Strong evidence

“DreamTeam Mobile is a trusted and reliable source for custom software development.”

Source: RevenueBase Database · checked Sep 24, 2026
7
GENUI
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-5013 contacts →

Partial evidence

“What sets GenUI apart is an end-to-end product focus throughout all our experience design and software development services.”

Source: RevenueBase Database · checked Sep 24, 2026
8
Itrellis, LLC
Strong evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-5013 contacts →

Strong evidence

“iTrellis is a Custom Software and Systems Integration consultancy located in Seattle, WA.”

Source: RevenueBase Database · checked Sep 24, 2026
9
Qubitsoft
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-5012 contacts →

Partial evidence

“Qubitsoft is an innovative and creative company that aims to meet its clients’ demands and provide original software solutions.”

Source: RevenueBase Database · checked Sep 24, 2026
10
Lunarbyte
Strong evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-1012 contacts →

Strong evidence

“Lunarbyte is a custom software and product development firm trusted by teams across industries to deliver dependable, scalable software solutions that drive real business results.”

Source: RevenueBase Database · checked Sep 24, 2026
11
Apsis Labs
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-1010 contacts →

Indirect evidence

“At Apsis Labs, we help product-driven teams bring high-quality web and mobile applications to life-quickly, cleanly, and with purpose.”

Source: RevenueBase Database · checked Sep 24, 2026
12
Gols INC
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-507 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 24, 2026
13
Pythonwise INC
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-506 contacts →

Indirect evidence

“Pythonwise Inc is leading provider of Information Technology consulting and business process services.”

Source: RevenueBase Database · checked Sep 24, 2026
14
Alpha Encoded
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-106 contacts →

Indirect evidence

“Based in the tech-centric city of Seattle, Alpha Encoded stands at the forefront of digital innovation.”

Source: RevenueBase Database · checked Sep 24, 2026
15
Pacific Automation Group
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-104 contacts →

Partial evidence

“We create and deploy tailor-made software solutions aimed at enhancing efficiency and optimizing operations for a diverse range of clients, spanning individuals, businesses…”

Source: RevenueBase Database · checked Sep 24, 2026
16
Zaifworks LLC
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-104 contacts →

Partial evidence

“Zaifworks is software development and cloud consulting firm that specializes in healthcare, real-estate and it services industries.* We transform, deploy and support what you are…”

Source: RevenueBase Database · checked Sep 24, 2026
17
Instrumental Group
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-103 contacts →

Partial evidence

“We are your software team for hire: four industry veterans with decades of cross-platform experience who have worked together for over a decade to launch products, run agencies…”

Source: RevenueBase Database · checked Sep 24, 2026
18
Ignia, LLC
Partial evidenceSeattle, United StatesHQ checked Sep 24, 20261-103 contacts →

Partial evidence

“Ignia is a software development agency specializing in the architecture, implementation and maintenance of localized, data-driven, multi-device web applications.”

Source: RevenueBase Database · checked Sep 24, 2026
19
joen.io
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-103 contacts →

Indirect evidence

“A boutique consulting firm based in Seattle, WA with offices in Orange County, CA specializing in Mobile App Development and Integration of Enterprise systems.”

Source: RevenueBase Database · checked Sep 24, 2026
20
Rogue POD LLC
Strong evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-102 contacts →

Strong evidence

“Rogue Pod has over 20 years combined experience in custom software development.”

Source: RevenueBase Database · checked Sep 24, 2026
21
Webonyx
Strong evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-502 contacts →

Strong evidence

“WebOnyx is a software development company that specializes in building custom software.”

Source: RevenueBase Database · checked Sep 24, 2026
22
dev.co
Strong evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-502 contacts →

Strong evidence

“Established in 2008 as a advertising & financial software consulting firm, DEV.co brings brings over 12 years of successful leadership to custom software development projects…”

Source: RevenueBase Database · checked Sep 24, 2026
23
Naos DEV Apps & WEB
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-102 contacts →

Indirect evidence

“We build mobile apps of all kinds and sizes.”

Source: RevenueBase Database · checked Sep 24, 2026
24
Buddio Tech
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-101 contacts →

Indirect evidence

“Buddio Tech build mobile apps.”

Source: RevenueBase Database · checked Sep 24, 2026
25
Inner Product LLC
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-101 contacts →

Partial evidence

“Inner Product builds great software for the enterprise.”

Source: RevenueBase Database · checked Sep 24, 2026

Showing 25 of 76 custom software agencies based in Seattle, United States

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Custom software agencies based in Seattle, United States at a glance

As of Sep 24, 2026
25.0%Verified-email coverage
7.3Average contacts per company
1-10Median size (employees)
680.3%Largest-city concentration · New York
Sep 24, 2026Page data refreshed

Companies by employee count

1-10
43
11-50
25
51-200
7
501-1,000
1

Email recency for this list is measured across the whole United States list rather than for Seattle, so it is reported there. Company counts and contact totals on this page are exact for Seattle, over 76 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among custom software agencies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in Seattle, United States whose own description of what they do matches “custom software agencies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names custom software agencies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among custom software agencies, and records with no verified work email. Companies headquartered outside Seattle are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
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 listed company carries at least one verified work email, 139 across the full list. 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 September 24, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Custom software agencies by metro in the United States

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names custom software agencies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many custom software agencies are there based in Seattle, United States?

RevenueBase identified 76 custom software agencies headquartered in Seattle, United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

White Rabbit Group, headquartered in Seattle, tops this list with the largest team on record.

Which city has the most custom software agencies?

New York leads with 517 headquartered companies, followed by Austin (307) and Houston (226).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 139 verified decision-maker contacts tracked across these 76 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 24, 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 Smart Search, 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.

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