The invisible backroom of the mobile

When you open the mobile app to order a taxi, when you pay by card, or when you watch a series on Netflix, these applications do not work in isolation. Behind them is an invisible network of digital infrastructures: APIs (Application Programming Interfaces). They are the digital backroom that makes the mobile ecosystem work, and without them, 80% of current applications would stop working.

Building applications like playing with Lego bricks

For years, applications, especially mobile ones, have not been built from scratch. Once promoters have formulated the business idea, programmers establish the operating logic – what the application should do – and then resort to external services for many operations: identifying the user, translating content, displaying maps, determining location, processing payments, or inserting ads. It's like building with Lego bricks: instead of manufacturing each piece, you take pre-made ones and combine them to create something new.

APIs are digital bridges that allow different applications to communicate with each other without user intervention. It's software talking to other software, with no visible interface. Rafael Granados, an API specialist and co-host of the podcast "APIcurios", explains it like this: "An API is like the waiter in a restaurant. You don't need to know the recipes for the dishes, just how to order them."

This way of working has been accelerated thanks to generative artificial intelligence tools like Claude Code, which, from a natural language description – called vibe coding– automatically write the code with the necessary API calls. What previously took days or weeks can now be done in hours.

This popularization will lead to exponential growth in API consumption. The global API management market, valued at 7 billion euros in 2024, will grow at a rate of 34.7% annually to reach 76 billion by 2032, according to Market Data Forecast.

The invisible giants that support applications

The API market is very diverse: the API Landscape website lists almost 2,700 providers. But the most visible categories for consumers are dominated by a few players. In maps, Google Maps controls 60% with over 5 million applications. Uber paid Google 55 million euros in three years just for this service. When you request a car, the application consults the Google Maps API to show you the route.

In personalized advertising, Google AdMob dominates with 86% integration. Facebook Audience Network has 23.5% of the market, Unity Ads is dedicated to video games, and AppLovin to optimization. These APIs allow a free application to generate revenue with a few lines of code: the in-app advertising market generated 325 billion euros in 2024.

Mobile payments depend on a few players: PayPal leads with a 45% global share and 435 million accounts, while Stripe controls 17% but is popular with developers for the clarity of its API. The company is valued at over 95 billion euros. In Spain, Bizum has become a ubiquitous system with over 30 million users. All these platforms charge commissions of 2.5-3%, plus a fixed amount per transaction.

Delegating collections via API saves the programmer from having to deal with hundreds of banking entities, payment method issuers, and currency exchange systems. Using a map API saves consolidating and maintaining billions of cartographic data points.

For identity verification, companies like Onfido cover 195 countries and 2,500 types of documents and verify identities in six seconds with 95% automation. For movie information, TMDb is the most popular API, free for non-commercial uses, while IMDb provides data to companies that can pay licenses of up to 140,000 euros annually.

APIs also play a growing role in public services. Recently, they have become topical with access incidents to open administration data on subsidies and contracts. In public transport, applications that report the position of trains or buses work thanks to free APIs from the operators.

Four business models

The API business combines various strategies. Freemium offers a free tier – generally between 1,000 and 10,000 monthly queries – and charges when these limits are exceeded. "Pay-per-query" charges for each request: Google Maps costs 6.50 euros per 1,000 map loads, Twilio 0.008 euros per SMS. Subscriptions range from 10-20 euros per month for personal projects to 500 euros or more for businesses. And transaction-based models, like Stripe and PayPal, take a percentage of each operation.

Save time and money

Although APIs do not eliminate obstacles such as the need for capital or critical mass of users, they reduce technical barriers and represent a radical saving. Developing a payment system from scratch can cost months and tens of thousands of euros; integrating Stripe is done in a couple of days. A proprietary mapping system would require 6-12 months; Google Maps is integrated in a week. 70% of developers plan to increase API usage and 90% of new business applications incorporate them.

Open Gateway: 'telcos' want their slice of the pie

Telephony operators also want to capture part of the API business. In 2023, they launched the GSMA Open Gateway initiative at MWC Barcelona, which brings together 73 operator groups with 285 networks covering 80% of the global mobile market to monetize the information generated by their networks.

Until now, if an application wants to know where the user is, it asks Google. With Open Gateway, it can consult it directly with the telephony operator, which knows it thanks to the antennas that provide coverage to the device. The 17 standardized APIs also allow verifying phone numbers without SMS, detecting SIM changes to prevent fraud, or guaranteeing quality of service for video games or streaming. McKinsey estimates it can provide telcos with 285 billion euros by 2030.

telcos 285 billion euros by 2030.

The API market continues to grow at a rate of 25-35% annually, driven by digital transformation and the proliferation of mobile devices. APIs are the invisible infrastructure that makes the digital economy possible: without them, we would have to build each service from scratch, and the application ecosystem as we know it simply wouldn't exist.