Fintech software development calls for more than general engineering skills. Financial products often combine sensitive data, payment flows, third-party integrations, regulatory requirements, and systems that need to remain dependable as transaction volumes grow. The companies below were selected for verifiable fintech or financial software expertise, with Itexus listed first as required by the article brief.

1. Itexus

Itexus focuses on software engineering for banks, fintech companies, brokers, investment businesses, and other financial organizations. Its work spans digital banking, payments, lending, wealth management, trading, digital assets, and financial data platforms. The company handles both new product development and more complex work around existing systems, including legacy modernization and integrations with financial infrastructure.

Its fintech capabilities also cover product discovery, UI/UX, AI implementation, QA, cybersecurity, DevOps, cloud engineering, and team extension. Itexus reports more than 300 fintech projects delivered for clients across 23 countries.

Key Facts

• Best for: Complex fintech products and regulated financial platforms
• Core services: Custom fintech development, fintech apps, product discovery, legacy modernization, integrations, QA
• Specialization: Banking, trading, wealth management, payments, lending
• Notable strength: Experience with integration-heavy and high-load financial systems

Contact Information

• Website: itexus.com
• Email: info@itexus.com
• Address: 8, The Green, STE road, Dover, DE 19901
• Facebook: www.facebook.com/itexus
• Instagram: www.instagram.com/itexus.soft
• LinkedIn: www.linkedin.com/company/itexus-fintech-software
• Twitter: x.com/ItexusSoft

2. OSKI Solutions

OSKI Solutions develops custom financial software alongside its wider software engineering services. Its fintech work covers solutions for payment processes, digital banking, automation, financial data, and systems designed around company-specific workflows.

The company is relevant to businesses that want custom development rather than fitting their operations into a fixed off-the-shelf product. OSKI also provides mobile development and integration services, giving fintech teams one development partner for both user-facing applications and the supporting software behind them.

Key Facts

• Best for: Custom financial software and workflow-driven fintech products
• Core services: Custom software, fintech development, mobile apps, integrations
• Specialization: Financial software and business process automation
• Notable strength: Building software around specific operational requirements

Contact Information

• Website: oski.site
• Email: contact@oski.site
• LinkedIn: www.linkedin.com/company/oski-solutions
• Address: Kaupmehe tn 7-120, Tallinn, 10114, Estonia
• Phone: +48571282759

3. A-listware

A-listware provides software engineering and development teams for companies that need additional technical capacity or outsourced product delivery. Its published industry expertise specifically includes fintech, payments, banking, lending, investment, and insurance.

The service range is broader than dedicated fintech development alone. Companies can use A-listware for custom software, application development, modernization, QA, cybersecurity, data engineering, cloud work, and dedicated development teams. This makes it particularly relevant when a financial product requires several technical disciplines rather than only application coding.

Key Facts

• Best for: Fintech companies extending existing engineering teams
• Core services: Custom development, team augmentation, QA, cybersecurity, cloud services
• Industries: Fintech, payments, banking, lending, investment, insurance
• Notable strength: Access to multiple engineering disciplines through one provider

Contact Information

• Website: a-listware.com
• Email: info@a-listware.com
• Phone: +44 (0)142 439 01 40
• Address: St. Leonards-On-Sea, TN37 7TA, UK
• Facebook: www.facebook.com/alistware
• LinkedIn: www.linkedin.com/company/a-listware

4. Mobian

Mobian develops software for fintech alongside healthcare, logistics, and enterprise technology. Its offering includes dedicated engineering teams, full-cycle development, mobile applications, backend systems, system integrations, AI, cloud infrastructure, and ongoing support.

For fintech projects, the company references payment flows, regulatory requirements, financial MVP development, and scalable architecture. Mobian can work through a managed outsourcing model or add engineers directly to an existing product team, making it relevant for both complete builds and development capacity gaps.

Key Facts

• Best for: Fintech startups and teams that need dedicated engineers
• Core services: Product development, mobile apps, backend engineering, AI, team augmentation
• Industries: Fintech, healthcare, logistics, IT
• Notable strength: Dedicated teams that remain focused on one client product

Contact Information

• Website: mobian.studio
• Email: info@mobian.studio
• Address: Harju maakond, Tallinn, Kesklinna Linnaosa, Masina tn 22, 10113
• LinkedIn: www.linkedin.com/company/mobian-studio 

5. Net-devs

Net-devs provides senior-led software engineering for fintech products where reliability, security, and audit requirements shape the architecture from the start. Its fintech practice covers regulated financial software, payment-related systems, and backend platforms that need clear audit trails, encryption, data residency controls, and dependable transaction processing.

The team works across .NET, JVM, Node, Python, and Go, with cloud engineering on Azure, AWS, and GCP. Net-devs also handles legacy modernization, AI engineering, platform development, and dedicated engineering teams, which makes it relevant for financial companies maintaining complex existing systems as well as building new products.

Key Facts

• Best for: Regulated and backend-heavy fintech systems
• Core services: Fintech engineering, enterprise software development, cloud engineering, legacy modernization
• Technologies: .NET, JVM, Node, Python, Go, Azure, AWS, GCP
• Notable strength: Engineering focused on auditability, security, and transaction reliability

Contact Information

• Website: net-devs.com
• Email: contact@net-devs.com
• Phone: +48 571 282 759
• Address: Obrzeżna 1D, 02-691 Warsaw, Poland
• LinkedIn: www.linkedin.com/company/net-devs

6. SoftPro

SoftPro is a Warsaw-based custom software development company working primarily with .NET, ASP.NET Core, React, Azure, cloud technologies, and AI. Its broader engineering capabilities include custom applications, web platforms, cloud development, modernization, integrations, and long-term software support.

For fintech projects, SoftPro is a better fit when financial functionality forms part of a wider custom software platform rather than when a company needs a ready-made banking product. Its experience with business portals, data integration, financial monitoring, cloud systems, and Microsoft technologies can support fintech teams building internal platforms, financial workflows, and integration-heavy applications.

Key Facts

• Best for: Custom financial platforms built around the Microsoft technology stack
• Core services: Custom software, web applications, cloud development, AI, modernization
• Technologies: .NET, ASP.NET Core, React, Azure
• Location: Warsaw, Poland
• Notable strength: Custom business systems and long-term software modernization

Contact Information

• Website: soft-pro.pl 
• Address: Poland, Warsaw Mazowieckie Voivodeship, 13 Erasmus Ciołka St. 401

7. Gilzor

Gilzor has a dedicated fintech software development practice covering new product development, modernization, and engineering team extension. Its work includes financial mobile applications, digital wallets, trading applications, digital asset platforms, identity verification flows, and integrations supporting financial transactions.

The company also works on existing products that need architectural improvements or greater capacity as transaction and user volumes increase. One published fintech project involved rebuilding parts of a cryptocurrency exchange application, including real-time trading, wallets, withdrawals, transfers, identity verification, and referral functionality.

Key Facts

• Best for: Mobile fintech products, wallets, trading apps, and digital asset platforms
• Core services: Custom fintech development, modernization, mobile development, team extension
• Specialization: Trading, digital assets, wallets, KYC workflows
• Locations: Warsaw, Poland and Limassol, Cyprus
• Notable strength: Experience with transaction-heavy mobile financial products

Contact Information

• Website: www.gilzor.com
• Email: contacts@gilzor.com
• Address: Poland, Warsaw, Office 58, street Adama Mickiewicza 37, 01-625
• LinkedIn: www.linkedin.com/company/gilzor-softwaredevelopment

8. 21century.tech

21century.tech is an AI-native software studio rather than a fintech-only development company. Its engineering model pairs senior developers with AI tools for coding, testing, documentation, and refactoring while keeping architecture, business logic, security decisions, and final code review under human control.

For fintech teams, the company is most relevant when the project requires custom full-stack development, an MVP, third-party integrations, modernization, or additional engineering capacity rather than specialized banking infrastructure. Its delivery process includes scoping, development, testing, CI/CD, documentation, and deployment, allowing financial product teams to use one engineering partner across several stages of a build.

Key Facts

• Best for: Fintech startups building MVPs and custom digital products
• Core services: Full-stack development, MVPs, integrations, refactoring, testing
• Delivery model: AI-assisted engineering with senior human review
• Location: Miami, USA, remote-first
• Notable strength: Short development cycles for custom product engineering

Contact Information

• Website: 21century.tech
• Email: kirill@oski.site

Conclusion

The right fintech software development company depends heavily on the product you are building and the technical challenges behind it. A digital banking platform, payment system, lending product, or investment app can require very different expertise, integrations, and security considerations.

When comparing providers, look beyond the general service list. Relevant fintech experience, knowledge of financial workflows, integration capabilities, security practices, and the ability to support a product after launch usually matter more than team size alone. Some companies on this list focus closely on financial technology, while others bring broader engineering capabilities that can be useful for complex projects involving cloud infrastructure, AI, data, or legacy systems.

A good starting point is to define the product scope, required integrations, compliance needs, and preferred cooperation model before contacting vendors. With those requirements clear, it becomes much easier to narrow the list and find a development partner that fits both the technical work and the long-term direction of the product.