Top C# Development Companies in Washington
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List of the Best C# Development Agencies and C# Developers in Washington
Certain agencies may be featured through sponsored placements. Rankings and SF Scores remain unbiased and are based solely on our evaluation methodology.
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Washington
4.9 (40 Reviews)
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and has 5+ verified reviews
4.9 (40 Reviews)
79
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
79
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
Custom software and AI development, scoped and priced before code
SoftDoes is a Kansas City custom software and AI development company, founded in 2019, that builds custom software, web platforms, mobile apps, MVPs and AI automation for startups, growing businesses and enterprise teams in the United States. One SoftDoes team handles discovery, UX and UI design, development, testing, launch and ongoing support. What SoftDoes builds: Custom software: internal operations platforms that replace spreadsheets, customer and patient portals, SaaS products and integrations, built with React, Node.js, Python and .NET on AWS and Azure. AI development: AI agents, chatbots, document extraction and workflow automation on OpenAI and Anthropic Claude models, added to the systems a business already uses. Web and e-commerce: custom web applications, business websites and online stores, including Shopify. Mobile apps: iOS and Android apps for customers and field teams. Best fit for SoftDoes, with results from client reviews: Operations teams replacing manual work: an educational support company cut time spent on administrative work by 30% and internal follow-up emails by 35%, and a real estate agency cut time spent on manual administrative tasks by 35%. AI automation: an education company cut student-teacher matching from 15 minutes to under 5. Enterprise and public sector: a $200,000+ reporting platform for a government agency with more than 10,000 employees cut reporting time by 30%. Customer-facing apps: a marketing company's new mobile app raised engagement by 34% and 90-day retention by 22%. "[SoftDoes] built our full AI-powered SaaS platform from scratch. They were communicative and reliable, consistently delivering quality work on schedule." (Upwork client review, AI-powered SaaS platform for construction) How SoftDoes prices work: every project starts with a written scope and price before any code is written. A paid discovery and estimate costs $490 and is credited toward the build. Hourly development starts at $50, AI automation projects at $2,500, MVPs at $8,000, dedicated developers at $4,000 per month and support plans at $500 per month. Clients own 100% of their code, accounts and IP from day one. Track record: as of October 2026, SoftDoes has completed more than 600 client engagements since 2020 and is rated 4.92 out of 5 across 283 rated engagements on Upwork and 5.0 on Clutch. SoftDoes is a member of the AWS Partner Network, a Zapier Silver Solution Partner and a Shopify Partner. SoftDoes carries general liability, professional liability (errors and omissions) and cyber liability insurance. A certificate of insurance is available on request.
See all 21+ Case Studies
$50-$99/hr
$1,000+
50 - 249
Kansas City, USA
Verified Client Review
Internal Platform Design & Development for a Manufacturing Company
Reviewed by: Anonymous, Analyst at Manufacturing Company View all 40 Reviews
5.0 (4 Reviews)
53
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
53
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
Empowering IT Solutions
Custom software, web development and IT business solutions provider company US, 18+ years experience in building mobile, cloud & web solutions. AllianceTek provides onshore client service and project management team along with overseas developers and designers to deliver the maximum benefit to our clients. We eliminate the hurdles and headaches often associated with the traditional outsourcing model. Our clients do not have to worry about culture gaps or communication problems that can arise from an overseas outsourcing firm. AllianceTek customers only interact with our US-based team members who understand the needs and expectations of American businesses. The AllianceTek model is able to offer clients the best in customer service while also providing cutting-edge, customized solutions at extremely competitive prices. We take pride in our ability to deliver cost-effective business solutions to customers while providing them with a world-class level of client service. Repeat customers and client referrals make up an integral part of our business, so the success of AllianceTek relies upon the satisfaction of our clients. AllianceTek continues to grow both its onshore and offshore teams. We understand the increasing technology demands of US businesses, and we will continue to position ourselves as a leading business solutions provider for our current and future clients. Contact us today for further information. Experience Matters:- 18+ Years in Business 580+ Successful Projects 110+ Team Members 9+ Global Location Core Expertise:- Enterprise class business applications and solutions Mobile and web applications Collaborative portals Custom CRM solutions Business intelligence solutions Business process automation
See all 23+ Case Studies
$25-$49/hr
$5,000+
50 - 249
Malvern, USA
Verified Client Review
Website Development for Sales Boot Camp & E-Learning Company
Reviewed by: Davis Carbo, Co-Founder & CEO at Combat Sales LLC View all 4 Reviews
4.7 (10 Reviews)
4.7 (10 Reviews)
31
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
31
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
OUR QUALITY, YOUR SUCCESS!
We are a collection of realists, strategists, developers, perfectionists, and idealists. We create amazing apps and software. Our primary objective as a leading enterprise is providing clients worldwide with digital transformation services and solutions. With a strong track record of more than a decade in the IT industry, 9series' experience is valued, with countless man-hours devoted to delivering cutting-edge services and solutions. We have built more than 65 mobile applications, successfully served more than 500 clients, and are dispersed throughout countries such as Sweden, Norway, Ireland, Finland, the United Kingdom, Germany, France, Italy, South Africa, Ghana, Kenya, the United States, Canada, Australia, Singapore, Malaysia, Turkey, Egypt, Iran, and the United Arab Emirates, among others.
View 9series Profile
$25-$49/hr
$1,000+
50 - 249
Seattle, USA
Verified Client Review
Web App Dev for Property Rental SaaS Platform
Reviewed by: Angel Ramos, CEO at ACuadrado Corp. View all 10 Reviews
0.0 (0 Reviews)
28
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
28
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
Partner for business application migration, modernization and AI integration
Softacom is a full-cycle partner for business application migration, modernization and AI integration. Since 2008, we have been helping companies across various industries transform legacy systems into reliable, future-ready solutions. We build on your existing software to deliver modern, high-performing applications with long-term value. Alongside migration and modernization, we design and integrate AI-driven solutions that automate processes and unlock new business opportunities. As a client-first company, we tailor our approach and technology stack to solve your specific business challenges. Our Services: - Software Migration (Delphi, .NET) - Software Modernization - AI Transformation Services - System Integration - Team Extension (Staff Augmentation, Dedicated Teams) - Custom Software Development - Cloud Development - Test Automation - Mobile Testing - UX/UI Design Why Choose Softacom 1. Standardized Approach We rely on a structured, test-driven development process supported by proprietary frameworks that help reduce costs without sacrificing quality. Our delivery methods are robust and transparent, ensuring predictable results and smooth collaboration throughout every project. 2. Quick Start Thanks to our wide network of proven developers worldwide, we can assemble a skilled and experienced team in as little as 3 weeks. This allows you to start your project quickly and move forward without delays. 3. Pre-Developed Migration Framework To accelerate migration projects, we use our proprietary AI-powered migration tool. It allows us to speed up delivery, reduce costs and handle even the most complex migrations with precision. 4. Vast Industry Experience Over the years, we have delivered projects for companies in banking, fintech, media and entertainment, manufacturing, automotive, energy, telecom, eCommerce, healthcare, and customer service. This broad expertise helps us understand industry-specific challenges and build solutions that fit. 5. Client-First Approach We don’t believe in one-size-fits-all solutions. Instead, we tailor our delivery models to your business requirements, ensuring that every project creates real value and solves your unique challenges.
View Softacom Profile
N/A
$10,000+
50 - 249
Seattle, USA
5.0 (2 Reviews)
5.0 (2 Reviews)
24
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
24
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
Triple-Vetted Nearshore Talent in LATAM
TECLA is a nearshore staff augmentation firm that helps startups, SMEs, brands, and enterprise companies build skilled teams in Latin America. We partner with businesses looking to hire remote developers, AI engineers, cloud experts, designers, product managers, QA testers, marketers, and other tech professionals who can seamlessly work alongside your in-house teams. We take care of everything—vetting, sourcing, onboarding, HR, and retention—so you can focus on growing your business with the right people in your team. Are you ready to interview highly-vetted talent in your own time zone? With over 50,000 candidates across countries like Argentina, Brazil, Mexico, Colombia, Chile, and Costa Rica, TECLA connects you with exceptional talent. Each candidate goes through a rigorous vetting process, covering English proficiency, communication, technical expertise, and references, with qualification matrices provided for every hire. Here’s some of the talent you can hire through TECLA: Software Developers AI Developers Cloud/DevOps Engineers Designers Product Managers QA Testers Data Scientists Our trusted clients include Drift, Article, HomeLight, Mercedes-Benz, and over 300 U.S.-based tech companies.
View TECLA Profile
$25-$49/hr
$25,000+
50 - 249
Seattle, USA
Verified Client Review
IT Staff Augmentation for Digital Studio
Reviewed by: Emilio Cueto, CTO at OnChain Studios, Inc. View all 2 Reviews
0.0 (0 Reviews)
0.0 (0 Reviews)
18
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
18
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
Digital Solutions Delivered!
Digital solutions are created by iTrellis. Using the tools and frameworks of your choosing, we develop, set up, integrate, and run applications for our clients on-premises, in different clouds, and at the edge. Delivered: Digital Solutions
View iTrellis Profile
N/A
$1,000+
10 - 49
Seattle, USA
0.0 (0 Reviews)
18
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
18
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
WE DESIGN & DEVELOP FRESH EXPERIENCES
Left and right brains come together as a team of designers, developers, and digital strategists. You will see that our breadth enables us to navigate a complex digital landscape so your company can expertly perform on a variety of platforms and channels, whether working with our creative team on UX design, our technical team on custom web app development, or letting Fresh Consulting help you discover the talent you're missing. We think that what makes Fresh fresh is how the worlds of business, technology, and design are integrated.
View Fresh Consulting Profile
$150-$199/hr
$10,000+
50 - 249
Bellevue, USA
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0.0 (0 Reviews)
2
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
2
SF Score
SF Score is calculated using our SARM methodology to evaluate agency expertise, market presence, and overall credibility. View Ranking Methodology
Seeking impact through engineering excellence
DSi is a global software engineering partner delivering scalable digital solutions and elite technical talent for over 25 years. We support startups, SMBs, and enterprise organizations across banking, legal tech, education, logistics, and other complex industries. Choose a flexible engagement model: augment your in-house team with specialized engineers who integrate seamlessly under your leadership, or rely on us for full-cycle custom software development with complete project ownership. Our services include end-to-end product design, architecture, development, QA, and long-term support—built with scalability, security, and performance in mind. DSi helps organizations accelerate innovation, reduce risk, and deliver high-impact technology solutions worldwide.
View Dynamic Solution Innovators Profile
$25-$49/hr
$100,000+
250 - 999
Redmond, USA
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