A mid-sized bank in the Philippines needs to launch a digital savings account within six months. Building the required infrastructure internally would take three years and cost tens of millions of dollars: a new core banking engine, a digital onboarding flow with KYC verification, a card issuance integration, and a mobile app connecting all of it. Instead, the bank contracts with a fintech platform that provides each of these functions through APIs. The digital savings product launches in five months. The bank’s engineering team wrote integration code. The fintech platform supplied the infrastructure.
That transaction, where a bank buys technology capabilities from a fintech provider rather than building them, has become the dominant pattern in banking modernisation. The banking-as-a-service market reached $18.6 billion globally in 2024 and is projected to grow to $73.7 billion by 2034 at a compound annual growth rate of 15.1%, according to Global Market Insights.
Why Banks Buy Instead of Build
Most banks operate on core systems built decades ago. Mainframe-based ledgers, batch-processing settlement engines, and monolithic account management platforms were designed for an era when banking happened in branches during business hours. These systems still process the majority of the world’s banking transactions, but they cannot support the real-time, API-driven experiences that digital customers expect.
Replacing a core banking system is among the most expensive and risky technology projects a bank can undertake. Multi-year timelines and nine-figure budgets are common. The risk of disrupting existing operations during migration keeps many banks locked into legacy infrastructure long past its useful life.
Fintech platforms offer an alternative: banks can layer modern capabilities on top of existing systems through API integrations. A bank that cannot rebuild its core ledger in less than three years can add a real-time payments capability in three months by integrating with a fintech platform’s API. The growth of API-driven banking platforms reflects this pragmatic approach to modernisation: incremental capability addition rather than wholesale system replacement.
The Scale of API Adoption in Banking
API adoption in banking has moved from experimental to standard. According to Coinlaw’s 2025 analysis of API statistics in financial services, 81% of banks worldwide have now adopted open banking APIs. The financial services sector processes over two billion API calls daily, and open banking APIs facilitated $676 billion in global transaction value in 2025.
The cost argument accelerates adoption. API-driven platforms achieved a 33% operational cost reduction for financial institutions in 2025, according to the same analysis. For a bank spending hundreds of millions annually on technology operations, a one-third cost reduction through platform adoption represents a compelling business case that internal development timelines cannot match.
The BaaS market structure reflects this demand. The platform segment accounted for 69% of the BaaS market in 2024, with cloud-based solutions holding 67% market share. In the United States alone, the BaaS market was worth $5.9 billion in 2024. The top seven providers, including Fiserv, Green Dot, and Finastra, controlled approximately 33% of the market, leaving substantial room for specialised providers in specific banking functions.
What Fintech Platforms Actually Provide
The term “fintech platform” covers a range of specific infrastructure capabilities that banks purchase rather than build.
Payments infrastructure is the most mature category. Fintech platforms process cross-border payments, real-time domestic transfers, and card transactions through APIs that banks integrate into their existing systems. A bank that lacks real-time payment rails can add the capability by connecting to a platform that already has the licences, banking relationships, and technical infrastructure in place.
Lending infrastructure allows banks to offer digital lending products without building underwriting engines, credit scoring models, or loan management systems from scratch. The platform handles origination, decisioning, and servicing. The bank provides the balance sheet and the customer relationship.
Compliance infrastructure addresses one of the most resource-intensive functions in banking. KYC verification, transaction monitoring, sanctions screening, and regulatory reporting all require specialised technology that fintech platforms can provide as a service. Fintech as a strategic priority for financial institutions is driven partly by the recognition that compliance technology built by specialists outperforms compliance systems built as afterthoughts within broader banking platforms.
How Platform Adoption Changes Bank Operations
Banks that adopt fintech platforms do not simply swap one vendor for another. The shift changes how the bank’s technology organisation operates.
In a legacy model, the bank’s IT team builds and maintains every system. Feature development timelines are measured in quarters. A new product launch requires months of internal development, testing, and regulatory approval for the underlying technology. In a platform model, the bank’s technology team focuses on integration and orchestration rather than infrastructure development. New capabilities can be added by connecting to additional platform APIs, reducing launch timelines from months to weeks.
This operational shift explains why 81% of banks have adopted open banking APIs. The banks that moved first discovered that platform integration allowed them to respond to competitive threats faster than internal development cycles permitted. Neobanks driving banking competition forced traditional banks to match digital product offerings on compressed timelines, and fintech platforms provided the only viable path to doing so.
The Risks and Limitations of Platform Dependence
Platform adoption is not without risk. Banks that rely on fintech platforms for core functions introduce concentration risk: if a platform experiences downtime or a security breach, the bank’s services are affected. Regulatory scrutiny of these arrangements has increased as regulators recognise that a single platform failure could affect multiple banks simultaneously.
Data governance presents another challenge. When a bank’s customer data flows through a third-party platform, the bank must ensure that the platform’s security standards, data residency practices, and access controls meet both regulatory requirements and customer expectations. The Global Market Insights data shows that cloud-based BaaS solutions dominate the market at 67% share, which means the majority of bank-fintech platform relationships involve customer data residing in cloud infrastructure managed by a third party.
Vendor lock-in is a practical concern. A bank that builds its digital lending product on a specific platform’s APIs may find switching to an alternative platform prohibitively expensive once the integration is embedded in its operations. The banks managing this risk most effectively use platform-agnostic integration layers that allow them to swap underlying providers without rebuilding their customer-facing products.
Despite these risks, the trajectory is clear. Fintech leading financial industry innovation is not a prediction but a description of how banking infrastructure investment is already flowing. The $18.6 billion BaaS market growing at 15.1% annually reflects a structural shift in how banks acquire technology capabilities, and that shift is accelerating as more banks discover that platform integration delivers results faster than internal development.
