The unexpected recipe to astound: take half a dozen APIs, an IBM Cloud, one Dallas mainframe, plus one iPad and gently fold in against a backdrop of a US-themed burger joint set in the heart of London on a bustling May evening. The result: a live demo of a Tweet-initiated, IBM Bluemix-enhanced, mainframe-powered business transaction cascade; that texted me on successful completion.

Oh, and my two astounded colleagues who just saw a whole new dimension to the way that mainframes deliver business services.

The digital generation of application developers – who have been weaned on Web2.0 and mobile apps – now expect to build the new IT world on Google- and Facebook-like APIs. If you look at these APIs, they provide elegantly simple, self-describing ways to build innovative new offerings from a unique combination of these foundation services. There is no waiting for a committee meeting to agree data structure or get permission to access a system. It’s all self service: someone with the hottest new idea can pull up a browser, check out the API schematics, enter a credit card number and GO! If the APIs don’t give you what you need, or you want to extend and encompass new ideas, simply look for other APIs and iteration two is born.

Let’s come back to my two stunned colleagues in London, who’d now cast aside the dessert menu to understand what they’d just seen…

It’s quite simple: opening Safari on my iPad, I had pointed it at a z Systems mainframe running in Dallas. With a quick login, we had a list of the business services available to us – everything from an address book look-up to information about sports celebrities (yes, IBM uses mainframes for all kinds of things!). No green screen; no VPN tunnel, no special client to download. Just a browser. On an iPad. We could see every last scrap of information we needed to start using these APIs: where to reach them, what information they need, what comes back – even how popular they are. If you were wondering about the deciphering a Cobol Copybook structure to allow your app to call the service, fear not, JSON is the name of the game for APIs and so it is here.

(I’m always astonished when I work with mobile app developers who increasingly dismiss XML as old-hat, never mind tried-and-trusted copybook structures!)

Now that we have a completely standardised web API interface, it’s simply a matter of composing and configuring a set of Bluemix services to listen out for a Twitter hashtag, call this set of APIs – running both CICS and IMS business services – and then text me. The remarkable thing is that Bluemix is completely unaware that it has just interacted with a dyed-in-the-wool z/OS application; it could just as easily have been posting a Facebook update or using the Google Maps API to populate a contextually-aware map.

Overcoming the surprise of seeing a digitally-ready mainframe in action we discussed at some length, helped by the timely arrival of dessert, the implications of this new world.

Suddenly we have a technology that allows us to discover – based on our subscription – any business service within, across and beyond our organisation. It allows us to blend together new ideas at the furious pace of change demanded by consumers. Just take one example: there is a new legislative directive (PSD2) that mandates the need for European Banks – and their trading partners – to provide regulatory information through an API. Yes, this is needed for compliance, but just imagine how organisations can flourish by allowing the next crop of innovative-thinkers to quickly and simply access business APIs to build the next Facebook.

Think this is unlikely? Check out the Citi Mobile API Challenge: this is exactly their mindset. In fact, in the Banking sector alone, this is API Economy has been valued at $300 billion in 2015.

Want to know more about this mainframe-API-enabling technology? Or you have brilliant experiences of the API Economy? I’d love to hear from you: tell me your ideas in the comments, below, or tweet me at @RichGx.

Author’s note: with true mobile inspiration at its heart, this article was written on an iPad at 38,000 ft somewhere over the North Atlantic.

Richard Gamblin is the Digital Transformation & Mobile Technical Leader for z Systems in Europe. Over the last eight years in IBM, Richard has worked closely with clients across multiple industries, who use WebSphere and Mobile technologies to change the way their businesses operate and perform.

Editors Note: Richard is a Brit (so his credibility is beyond reproach) and he also does an excellent impression of Apple’s Jony Ive after a few beers…