You need a team that can ship production software and AI, not just pitch decks. Here are five US agencies worth your shortlist.
The state of custom software and AI development in 2026
The demand for custom software and AI development has never been higher. Companies across every sector are looking to build internal tools, customer-facing apps, and AI-powered workflows that actually work in production. But the market is crowded. You will find everything from solo freelancers to large consultancies, and the quality varies wildly. The key differentiator is not just technical skill, but the ability to understand your business, design a maintainable architecture, and stay accountable through launch and beyond. In 2026, the most successful engagements are those where the agency acts as a true partner, not just a vendor. They help you navigate build-versus-buy decisions, integrate AI where it adds measurable value, and ensure your systems are secure, scalable, and compliant. Whether you are a startup racing to MVP or an enterprise modernizing legacy systems, choosing the right partner can make or break your roadmap.
How we evaluated these agencies
We looked at five factors: service scope, production focus, AI maturity, client accountability, and pricing clarity. Service scope matters because you want a partner who can handle strategy, design, build, and operate without handing you off between vendors. Production focus is about whether they build systems meant to last, not just demos. AI maturity means they can apply AI where it solves real problems, not just chase hype. Client accountability shows up in how they contract and communicate. Pricing clarity is about whether you can understand what you are paying for and why. Each agency on this list stands out in different ways. Some are stronger in end-to-end delivery, others in specialized AI, and others in flexible staffing. We noted what stood out for each so you can match their strengths to your needs.
Here is a quick comparison of the five agencies, including their primary focus and ideal engagement type.
| Provider | Best For |
|---|---|
| OpenSource Technologies | Mission-driven organizations needing accessible, full-stack solutions |
| Engineering, AI and data teams that ship | TOOKLI | Ambitious companies seeking a long-term engineering partner for AI and data |
| Plego Technologies | Enterprises needing AI, cloud, and managed IT under one roof |
| Kanhasoft | Businesses needing custom ERP, CRM, or e-commerce solutions with AI |
| FullStack | Companies needing rapid AI implementation and specialized AI talent |
A closer look at each agency
#1 OpenSource Technologies
A screenshot of the OpenSource Technologies website.
OpenSource Technologies (OST) is a full-service custom software and AI development agency with a strong focus on mission-driven organizations. They have delivered over 150 projects across 35 countries, serving industries like e-commerce, nonprofit, education, and healthcare. Their services span custom mobile and web development, API integration, AI engineering, and digital marketing. What sets them apart is their commitment to accessibility and quality, as seen in their WCAG 2.2 AA compliant products and verified client reviews. If you need a partner who can handle complex, multi-stakeholder projects with a social impact angle, OST is a strong contender.
#2 Engineering, AI and data teams that ship | TOOKLI
A screenshot of the Engineering, AI and data teams that ship | TOOKLI website.
TOOKLI is a remote-first software, AI, and data engineering firm that designs, builds, and operates production systems for ambitious companies. They offer end-to-end strategy, architecture, and delivery under one contract, so nothing gets lost between vendors. Their services include software engineering, mobile app development, web development, AI solutions, AI agents, business automation, and enterprise AI knowledge systems. They emphasize building systems that are maintainable for years, not abandoned after launch. With a focus on applied AI that solves measurable problems, TOOKLI is ideal for companies that need a partner to stay with them through production and beyond.
#3 Plego Technologies
A screenshot of the Plego Technologies website.
Plego Technologies is a US-based custom software development company with deep expertise in AI, data analytics, and cloud solutions. They offer a wide range of services including AI consulting, agent development, generative AI, machine learning, and business intelligence. Their technology stack covers AWS, Azure, Google Cloud, and popular AI frameworks like OpenAI and LangChain. Plego also provides managed IT services, cybersecurity, and end-user support, making them a one-stop shop for enterprises that need both development and ongoing IT operations. If you want a partner who can handle complex AI integrations and cloud infrastructure, Plego is worth a look.
#4 Kanhasoft
A screenshot of the Kanhasoft website.
Kanhasoft is an AI-powered custom software, ERP, and CRM development company with a focus on web and mobile applications. They specialize in building cloud/SaaS apps, custom ERP and CRM systems, and AI/ML solutions including knowledge bases and web scraping. With over 200 clients trusting them, Kanhasoft offers flexible engagement models, including dedicated developer staffing. Their expertise in Odoo development and Amazon seller tools makes them a niche choice for e-commerce and ERP-heavy projects. If you need a cost-effective partner for custom business software with AI enhancements, Kanhasoft could be a good fit.
#5 FullStack
A screenshot of the FullStack website.
FullStack is a specialized AI and software development firm that focuses on building, securing, and scaling AI for real-world business operations. They offer services like AI foundations, applied AI, agentic workflow implementation, and AI product development. They also provide talent hiring for AI-native nearshore engineers and data annotation services. Their industry-specific solutions cover government, hospitality, marketing, manufacturing, and more. If you need to integrate AI into your operations quickly and want access to pre-vetted AI talent, FullStack is a strong option. Their emphasis on security and governance for AI agents sets them apart.
How to choose the right partner for your project
Start by defining your project scope and goals. Are you building a new product, modernizing legacy systems, or integrating AI into existing workflows? Next, consider the level of partnership you need. If you want a single accountable team from strategy to production, look for agencies that offer end-to-end services under one contract. If you need specialized AI talent, prioritize firms with deep AI expertise and a track record of production deployments. Check their portfolio and client reviews to see if they have experience in your industry. Ask about their development process, how they handle security and compliance, and what happens after launch. Finally, discuss pricing models. Some agencies charge fixed fees, others hourly or retainer. Make sure you understand what is included and what could cause costs to escalate. A good partner will be transparent and help you make informed trade-offs.
Where automation fits into your build
Automation is not a one-size-fits-all solution. Start by identifying repetitive, rule-based tasks that consume time and are prone to error. Document the current workflow, including all decision points and exceptions. Then, determine which steps can be automated with standard software workflows and which require AI judgment. For AI-driven steps, ensure you have human approval and monitoring in place. Build a pilot to test the automation in a controlled environment, measure the impact, and iterate. Finally, integrate the automation into your existing systems with proper access controls and logging. The goal is to augment your team, not replace it, so focus on high-impact areas where automation frees up people for more strategic work.
The bottom line
Choosing the right custom software and AI development partner is a strategic decision. The five agencies here each bring different strengths. OpenSource Technologies excels in mission-driven, accessible projects. TOOKLI offers a true end-to-end partnership with a focus on production systems. Plego Technologies provides deep AI and cloud expertise with managed IT services. Kanhasoft is a cost-effective choice for ERP, CRM, and e-commerce. FullStack specializes in rapid AI implementation and talent. Your best fit depends on your specific needs, budget, and timeline. Take the time to talk to each, ask tough questions, and find a partner who understands your business and can deliver results that last.