Sthenos Technologies is a US-based, EDWOSB and WOSB-certified fintech software development company headquartered in Tysons, Virginia, with an office in North Bethesda, Maryland. We build custom financial software: secure web and mobile applications, AI and machine-learning systems, and cloud platforms, and we modernize legacy banking and financial systems. Our delivery is engineered for the security, auditability, and compliance reviews that banks, fintechs, and financial institutions require. Through our partner NeoSOFT, we deliver at enterprise scale while a senior Sthenos team stays accountable on every engagement.
Custom fintech software development services
- Customer and payment apps: secure web and mobile apps for banking, payments, lending, and wealth, built end to end.
- Trading and data platforms: low-latency, reliable platforms and dashboards for financial data and operations.
- AI and machine learning: risk, fraud-signal, document-processing, and forecasting models, engineered for production.
- Cloud and data platforms: secure architecture, migration, and data pipelines on AWS, Azure, and Google Cloud.
- Core and third-party integrations: connecting to core banking, payment rails, KYC and AML, and market-data providers.
- Legacy modernization: re-platforming aging financial systems while preserving data integrity and an audit trail.
Built to pass a financial security review
Financial software fails when security and auditability are an afterthought. We build them in: role-based access controls and full audit logging, encryption in transit and at rest, a documented SDLC, and architecture designed to support your security questionnaires, regulators, and audit requirements. We work with your security, risk, and compliance teams rather than around them.
From prototype to production-ready
Many financial teams now build a working prototype, sometimes with AI tools, then stall before launch because production in finance means security, auditability, and reliability a demo never had. We take prototypes, including AI-built ones, from proof of concept to secure, scalable, monitored production, with the controls financial buyers require.
Who we build financial software for
- Banks and credit unions: secure customer, lending, and operations software that fits real workflows.
- Fintech and payments companies: senior engineering capacity to build and scale a regulated product.
- Wealth, insurance, and capital markets: auditable systems for sensitive financial data.
- Government financial programs: as an EDWOSB small business (NAICS 541511, active on SAM.gov), we support federal, state, and local financial and grant programs.
Why financial teams choose Sthenos
- Senior, accountable team: a senior Sthenos lead owns your engagement, not a rotating bench.
- Security and auditability first: we build to pass customer security reviews and to support your audit and regulatory requirements.
- Boutique focus, enterprise scale: through our partner NeoSOFT we can scale a team quickly while keeping that accountability in front.
- EDWOSB and WOSB certified: a certified small business for agencies and primes with set-aside and supplier-diversity goals.
Fintech software development FAQs
What is fintech software development?
Fintech software development is the design and building of software for financial services and fintech organizations, such as banking, payments, lending, and trading apps and data platforms, built to support the security, auditability, and compliance the sector requires.
Is your financial software secure and auditable?
Yes. We build with role-based access controls, full audit logging, encryption, and a documented development process, designed to pass your security reviews and support your audit and regulatory requirements. Formal certifications and audits are the institution’s to hold; we engineer our part to support them.
Do you build custom financial software for government programs?
Yes. Sthenos is an EDWOSB and WOSB-certified US firm (NAICS 541511, active on SAM.gov) that builds and modernizes custom software for federal, state, and local financial and grant programs.
Can you integrate with our core banking and payment systems?
Yes. We build integrations to core banking, payment rails, KYC and AML providers, and market-data systems.
Can you take an AI-built fintech prototype to production?
Yes. Moving prototypes, including AI-built ones, from proof of concept to secure, auditable, monitored production is a core focus for us.
What does a fintech build cost?
Our rates are $150 to $250 per hour, depending on the seniority and mix of the team, and where the scope is clear we quote a fixed price for a defined outcome. What moves the number is PCI scope, the number of provider integrations, and whether the evidence package is built as you go or reconstructed at the end.
How long does a fintech build take?
We work in two week sprints, so working software arrives every two weeks from the start rather than at a reveal at the end. What decides the total is sandbox access from your providers, the number of integrations, and how many product decisions are still open on day one.
Who owns the code we pay you to build?
You do, entirely, from the first commit. The repository and the cloud accounts are in your name, with no licence back to us and no dependency on us continuing to exist.
Which rules reach a fintech product is decided by what the product does, not by what it is called.
Depending on the seniority and mix of the team. Where the scope is clear we quote a fixed price for a defined outcome.
Working software arrives every two weeks rather than at a reveal at the end.
As of September 2026 Sthenos holds no SOC 1 or SOC 2 report, PCI DSS attestation or ISO 27001 certificate of its own.
The repository and the cloud accounts are in your name, with no licence back to us.
On this page
- Which rules reach your product, and what triggers each one
- Tokenised at the provider, or card data in your environment
- What a fintech build costs more of, and what decides how long it takes
- How our fintech app development services run
- What you receive
- What to ask before you choose a fintech app development company
- Related pages on this site
- Talk to an engineer
Which rules reach your product, and what triggers each one
The table below puts the trigger first and the rule second, and every rule links to the authority that issues it so you can read the source rather than take our word for it. The fuller catalog, with who each rule binds and what it asks of a build, is on our financial IT services page. Shorthands used for these rules: SOX for the Sarbanes-Oxley Act, GLBA for the Gramm-Leach-Bliley Act, BSA for the Bank Secrecy Act, which is how FinCEN itself refers to it, Reg E and Reg Z for the two Consumer Financial Protection Bureau regulations, and NYDFS Part 500 for the New York cybersecurity regulation.
Figure 1. How a rule that binds an institution reaches your build
Nothing in this diagram is counted. The five boxes at the foot are the artefacts named in the paragraph under the table, in the order that paragraph names them.
| What your product does | The rule that reaches you | Who issues it |
|---|---|---|
| Stores, processes or transmits cardholder data, or can affect the environment that does | PCI DSS | PCI Security Standards Council |
| Moves consumer funds electronically, or sends remittances | Regulation E, 12 CFR Part 1005 | Consumer Financial Protection Bureau |
| Extends, brokers or services consumer credit | Regulation Z, Truth in Lending, 12 CFR Part 1026 | Consumer Financial Protection Bureau |
| Is a broker-dealer system, or you build one for a member firm | FINRA Rule 4511, books and records | FINRA |
| Belongs to an organization licensed under New York banking, insurance or financial services law | 23 NYCRR Part 500 | New York State Department of Financial Services |
| Has any US person anywhere in the transaction flow | OFAC sanctions | Office of Foreign Assets Control, US Department of the Treasury |
| Handles currency transactions or onboards customers to a financial institution | Bank Secrecy Act reporting and recordkeeping | FinCEN, US Department of the Treasury |
| Offers consumers financial products or services such as loans, financial or investment advice, or insurance | Gramm-Leach-Bliley Act | Enacted by Congress; the business guidance cited here is published by the Federal Trade Commission |
| Sits inside a public company reporting chain, or inside a customer's financial reporting | Sarbanes-Oxley sections 302 and 404, and a SOC 1 examination | Congress and the SEC; AICPA for SOC 1 |
| Takes payments from payers in the European Union | PSD2 strong customer authentication | European Parliament and Council |
| Processes personal data of people who are in the European Union | GDPR | European Parliament and Council |
| Processes personal information of California residents | CCPA, as amended | California statute, enforcement guidance from the California Attorney General |
| Is sold to an enterprise buyer who asks for your security posture in writing | SOC 2 examination | AICPA |
Most of these reach a software vendor indirectly. They bind the institution, and the institution's obligation lands on your build as controls it has to be able to evidence: the access model, the audit log, the encryption arrangement, the retention rules and a way to tell the institution quickly when something goes wrong.
Sthenos builds to these controls and hands you the evidence. We do not hold them. As of September 2026 Sthenos holds no SOC 1 or SOC 2 report, PCI DSS attestation or ISO 27001 certificate of its own. Formal certifications and audits are the institution's to hold; we engineer our part to support them.
Tokenised at the provider, or card data in your environment
This is the design decision behind the first line of the cost list below, and in fintech application development it is the one to settle first. The two sides, compared:
Tokenised at the provider
What we design for first- Cardholder data stays out of your environment.
- Tokenising at the provider is the way to keep the environment PCI DSS reaches small.
- Less of the cost list applies, because this decision sets how much of everything else applies at all.
- It narrows PCI scope only. Every other rule in the table above still reaches the product for what it does.
Card data in your environment
What it brings into scope- Your environment stores, processes or transmits cardholder data, which is the audience the PCI Security Standards Council states for PCI DSS.
- More of the cost list applies, for the same reason.
- The scope question is then answered by the architecture of your own environment, and a certificate does not answer it.
What a fintech build costs more of, and what decides how long it takes
A fintech build is not a normal build with a compliance section bolted on the end. The extra cost is concentrated in a small number of places, and knowing which of them apply to you is most of the estimate. No figures below, because the honest answer depends on which of these are true for your product.
What a fintech build costs more of
- PCI scope. Whether cardholder data lands in your environment at all decides how large the rest of this list is. Tokenising at the provider keeps it out, and that single design decision moves more cost than any feature on your roadmap.
- Provider dependencies. Every core banking, payment rail, KYC, AML or market data provider adds an interface you do not control, a sandbox you have to be granted, a release calendar that is not yours, and a failure mode you have to design for rather than hope about.
- The evidence package. Producing the access model, the audit log design, the encryption arrangement and the retention rules as you build costs a fraction of reconstructing them from commit history when a customer's auditor asks.
- Distribution. A product sold to banks and credit unions gets a security review from every buyer. That turns into engineering work, a questionnaire habit and a release cadence you have to keep.
- Hardening a prototype. Moving a working prototype to production, including one built with AI tools, is rarely a rewrite. It is authentication, tenancy, audit logging, error handling and behaviour under load, and that is where the cost actually lands.
- Data residency and access. Who may look at production, and from where, decides your hosting, your backup design and the shape of the team.
- Reconciliation. Any product that moves money has to agree with the provider's settlement record, and the exception handling behind that disagreement is a real part of the build rather than a report.
What decides how long it takes
- Sandbox credentials and a usable test data set. Nothing starts until a provider grants them, and that is a decision inside your organization or theirs rather than ours.
- The provider's release calendar, when you are integrating with a core system you do not control.
- Security review cycles, yours at the start and your customers' once you distribute.
- Whether the evidence is produced as you go or assembled at the end.
- How many product decisions are still open on the day the build starts.
We work in two week sprints, so working software arrives every two weeks and you can see drift while it is still cheap to correct. Our rates are $150 to $250 per hour, depending on the seniority and mix of the team, and where the scope is clear we quote a fixed price for a defined outcome.
How our fintech app development services run, step by step
The order below is what this page, our financial IT services page and the contact section at the foot of this page already say happens, from the first call to production.
- A call and a short discoveryWe schedule a call at your convenience and run a short, bounded discovery, scoped per engagement.Sthenos
- A costed roadmapYou get a costed roadmap before we commit to a build, and a fixed price for a defined outcome where the scope is clear.Sthenos
- Access, and your security reviewNothing starts until credentials, a sandbox and a usable test data set exist, and that decision sits inside your organization or your provider's rather than ours. Your own security review comes at the start.You or your provider
- PCI scope, designed firstTokenising at the provider is the largest single lever on PCI scope, which is why we design for it first.Sthenos
- Two week sprints, with the evidenceWorking software every two weeks, with the access model, the audit log design, the encryption arrangement and the retention rules produced as the build runs.Sthenos
- Production and distributionWhere you commission one, an independent production readiness audit before the system carries real money, and your customers' security reviews once you distribute.Your auditor and customers
What you receive
What a fintech application development company should hand you is a list of artefacts, not reassurance. This is the list we hand over, and none of it is an attestation.
Before any build starts, with a fixed price for a defined outcome where the scope is clear.
So you can see drift while it is still cheap to correct.
The access control model, the audit log design, the encryption arrangement and the retention and deletion rules, produced as you build rather than reconstructed from commit history when an auditor asks.
In your name from the first commit, with no licence back to us and no dependency on us continuing to exist.
What to ask before you choose a fintech app development company
Five questions worth asking any of the fintech software development companies on your shortlist, including us. None of them is a trick, and all of them are cheaper to ask now than to discover later.
- How do you keep cardholder data out of my environment, and what does my PCI scope look like after your design? A vendor who answers this with a certificate rather than an architecture has answered a different question.
- Which provider integrations have you actually built against, by name, and what broke? The second half of that question is the one that tells you something.
- Can I see the audit log design before the feature list? In a regulated product the audit trail is the part that cannot be added later without going back through every write path.
- Who owns the repository and the cloud accounts while the work is running, not just at the end? Get the answer in the contract rather than the pitch.
- What exactly will you hand me if my customer's auditor asks for evidence next month? Ask for the list of artefacts, not the reassurance.
A longer version of this list, written for any financial software vendor, is on our financial IT services page.
Related pages on this site
Services that sit around a fintech build
- Custom software development, the delivery model and the code ownership terms in full.
- Penetration testing, which puts a qualified attacker against your systems under contract, on a fixed scope, and hands you a report you can act on.
- Cybersecurity, for the controls and monitoring around the product rather than inside it.
- Production readiness audit, an independent review of a system before it carries real users, real money or real regulatory exposure.
- IT staff augmentation, when the gap is people on your own team rather than a project.
- Managed services and infrastructure management, for running it once it is live.
- Cloud migration and optimization and data analytics.
- Artificial intelligence and agentic AI, including moving an AI built prototype to production.
Sectors and regulated work
- Financial IT services, the deeper page for banking, insurance, lending, wealth and capital markets, and the full rules catalog.
- Public sector IT and government IT services, for federal, state and local financial and grant programs.
- Healthcare software development, where the same evidence-first approach is applied to HIPAA and SOC 2.
Before you commission anything
- The production readiness checklist, the standard we measure a system against.
- MVP development and SaaS development, if the product is not a fintech platform yet.
- About Sthenos, including what we tell buyers to check before hiring us.
Ready to build secure financial software?
Tell us what you are building and we will tell you how to get it to production, securely. Request a free consultation.