Banks and fintech businesses in Washington need different development partners depending on what they are building: a mobile banking app, a payment integration, or a replacement for aging software. The entries highlight relevant services, delivery models, and locations so readers can build a shortlist around their project.
1. Itexus
Itexus develops custom financial software for banks, credit unions, investment businesses, and fintech companies. Its portfolio includes mobile banking applications, a white-label banking app, and a digital customer onboarding platform with automated KYC and KYB verification. Services cover discovery, interface design, development, testing, cloud engineering, and ongoing support.
For Washington businesses open to remote delivery, Itexus offers dedicated development teams and individual specialists who can join an existing engineering team. Its published offices are in Dover, Delaware, and Warsaw, Poland. The combination of banking projects and flexible engagement models makes it a relevant option for organizations building a new product or extending existing financial software.
Key Facts
- Core services: Banking software development, custom financial software, mobile banking development, QA, DevOps, and support.
- Project experience: Customer onboarding, mobile banking, and investment applications.
- Delivery models: Dedicated teams, staff augmentation, and project delivery.
- Location: Dover, Delaware, and Warsaw, Poland; remote delivery.
Contact Information
- Website: itexus.com
- E-mail: moc.suxeti@ofni
- Facebook: www.facebook.com/itexus
- Twitter: x.com/ItexusSoft
- LinkedIn: www.linkedin.com/company/itexus
- Instagram: www.instagram.com/itexus.soft
- Address: 8, The Green, STE road, Dover, DE 19901
2. Slalom
Slalom combines business consulting with software, platform, and data engineering. Its Seattle office provides a local presence, while its financial services practice covers banking and payments, capital markets, insurance, and wealth management. Relevant capabilities include digital product development, systems integration, cloud modernization, and data architecture.
That breadth makes Slalom worth considering when a banking software project also requires changes to internal processes or customer experience. A bank connecting several applications, rebuilding a customer-facing service, or improving the data behind its operations may need this combination of planning and implementation. Slalom's offering extends across those connected areas rather than being limited to application coding.
Key Facts
- Core services: Product engineering, systems integration, cloud modernization, and data engineering.
- Industry focus: Banking and payments within a wider financial services practice.
- Project fit: Software programs involving technology, customer experience, and operational change.
- Location: Seattle, Washington.
Contact Information
- Website: www.slalom.com
- Twitter: x.com/slalom
- LinkedIn: www.linkedin.com/company/slalom-consulting
- Address: 255 S King St, Suite 1800, Seattle, Washington 98104
3. Jelvix
Jelvix offers banking and financial software development alongside enterprise engineering and technology consulting. Its financial services work covers payment processing, investment management, process automation, and integrations with third-party APIs. The company lists Seattle among its locations, with its global headquarters in Tallinn, Estonia.
Its service range is relevant to organizations that need custom financial functionality connected to a broader enterprise system. Development can be supported by dedicated teams, mobile engineering, QA, technical support, and DevOps consulting. For a buyer comparing vendors, Jelvix is a potential fit for projects where payment workflows, financial data, and existing applications need to work together.
Key Facts
- Core services: Financial software development, mobile applications, QA, and dedicated teams.
- Relevant capabilities: Payment processing, investment tools, automation, and API integration.
- Location: Seattle presence; global headquarters in Tallinn, Estonia.
Contact Information
- Website: jelvix.com
- E-mail: moc.xivlej@olleh
- Facebook: www.facebook.com/JelvixCompany
- Twitter: x.com/jelvix
- LinkedIn: www.linkedin.com/company/jelvix
- Instagram: www.instagram.com/jelvix
- Address: Kaupmehe tn 7, 10114 Tallinn, Estonia
- Phone: +1 240 507 54 71
4. EPAM
EPAM serves retail and commercial banks, investment banks, payment providers, and wealth management organizations. Its engineering services include platform development, API integration, modernization, cloud work, and quality engineering. The company has an office in Bellevue, providing a Washington location within its international delivery network.
EPAM is a relevant candidate for banking projects with several technical workstreams, such as modernizing applications while updating their integrations and data infrastructure. Its financial services coverage extends beyond consumer banking into payments and capital markets. That range can be useful for institutions whose software must connect customer channels with more complex financial systems and operations.
Key Facts
- Core services: Platform engineering, API integration, modernization, cloud services, and testing.
- Financial sectors: Retail and commercial banking, investment banking, payments, and wealth management.
- Project fit: Enterprise financial software development and modernization.
- Location: Bellevue, Washington.
Contact Information
- Website: www.epam.com
- Facebook: www.facebook.com/EPAM.Global
- LinkedIn: www.linkedin.com/company/epam-systems
- Instagram: www.instagram.com/epamsystems
- Address: 10900 NE 8th St, Suite 1680, Bellevue, WA 98004
- Phone: +1 267 759 9000
5. Seattle Software Developers
Seattle Software Developers builds financial applications for banking, payments, and money management. Its financial development services include payment gateway integration, personal finance tools, trading platforms, and fraud detection systems. These sit within a broader offering of custom software development, cloud applications, and staff augmentation.
The company describes a delivery process that runs from planning and architecture through development, launch, and ongoing improvements. Businesses can engage a dedicated team to handle a build or add developers to an existing project. Its financial application offering is particularly relevant when the scope centers on a specific customer application, transaction workflow, or financial tool.
Key Facts
- Core services: Financial application development, custom software, and staff augmentation.
- Relevant capabilities: Payment integrations, personal finance tools, trading applications, and fraud detection.
- Delivery models: Full project delivery or support for an existing team.
- Market presence: Seattle area, Washington.
Contact Information
- Website: seattlesoftwaredevelopers.com
- E-mail: moc.srepolevederawtfoselttaes@olleh
- Facebook: www.facebook.com/people/Seattle-Software-Developers
- LinkedIn: www.linkedin.com/company/seattle-software-developers
- Instagram: www.instagram.com/seattle.software.developers
- Address: 4 102nd Ave NE, Bellevue, WA 98004
- Phone: (425) 307-9066
6. Globant
Globant's banking practice develops digital channels, integrates cloud services, and supports process modernization. Its published banking work includes a digital transformation engagement with Itaú and robotic process automation for IDB Bank.
For banks evaluating a broader digital program, Globant combines application development with customer experience and workflow improvements. Its banking services cover prototypes as well as larger implementations, including web applications and AI-supported processes. This makes it relevant to institutions that want to develop customer-facing services while also changing how the supporting operations work.
Key Facts
- Core services: Digital banking channels, cloud integration, process automation, and software implementation.
- Published banking projects: Itaú and IDB Bank.
- Project fit: Banking experiences connected with operational modernization.
- Location: Seattle, Washington.
Contact Information
- Website: www.globant.com
- E-mail: moc.tnabolg@ih
- Facebook: www.facebook.com/Globant
- Twitter: x.com/globant
- LinkedIn: www.linkedin.com/company/globant
- Address: 1601 5th Avenue, #603, WA 98101, Seattle
- Phone: +1 786-841-1898
7. AccelOne
AccelOne operates from Kirkland, Washington, and Buenos Aires, Argentina, with professionals across the United States and Latin America. Its financial software portfolio includes a cryptocurrency reconciliation engine for Xapo, a credit empowerment platform, and a decentralized lending platform.
The company provides product design, software engineering, modernization, testing, deployment, and support. Clients can choose full product delivery or staff augmentation. AccelOne is particularly relevant to financial projects involving transaction reconciliation, digital wallets, lending functionality, or integrations. Its work gives buyers specific financial engineering examples to discuss when assessing whether the team matches their own banking software requirements.
Key Facts
- Core services: Product design, software engineering, modernization, testing, and support.
- Financial project experience: Reconciliation, digital wallets, credit platforms, and decentralized lending.
- Delivery models: Full product delivery and US or nearshore staff augmentation.
- Location: Kirkland, Washington, and Buenos Aires, Argentina.
Contact Information
- Website: www.accelone.com
- E-mail: moc.enolecca@ofni
- LinkedIn: www.linkedin.com/company/accelone
- Address: 608 State St, Kirkland, WA 98033
- Phone: +1 (800) 863-6814
8. Zazz
Zazz develops fintech applications with mobile banking, digital wallet, payment, and account management functionality. Its services cover interface design, custom development, integration, QA, deployment, and maintenance.
Its financial application offering includes balance views, transaction histories, statements, payment transfers, and user authentication. Zazz also describes cross-platform development using React Native and Flutter. These capabilities make it a relevant option for banking and fintech teams focused on a mobile product, particularly when the same core experience needs to work across multiple devices and connect with external financial services.
Key Facts
- Core services: Fintech app development, UI/UX design, integration, QA, and maintenance.
- Relevant functionality: Mobile banking, digital wallets, payments, and account management.
- Technologies: React Native and Flutter for cross-platform applications.
- Location: Bellevue, Washington.
Contact Information
- Website: www.zazz.io
- Facebook: www.facebook.com/Zazz.Official
- Twitter: x.com/Zazz\_Official
- LinkedIn: www.linkedin.com/company/zazz-io
- Instagram: www.instagram.com/zazz.io
- Address: 2018 156th Ave NE, Bldg F #100, Bellevue, WA 98007
Conclusion
Washington businesses have a range of banking software development partners, from local engineering teams to large international consultancies and remote fintech specialists. The companies in this list cover different needs, including mobile banking, payment systems, API integration, cloud modernization, data engineering, financial applications, and digital transformation. The right choice depends on the project's technical scope, financial domain, delivery model, and need for local collaboration. Reviewing relevant project experience, services, technologies, and engagement models can help narrow the shortlist to a partner that matches the bank's specific software requirements.