As a product designer or application developer, the most important thing to focus on should be delighting your users. After all, the only part of the product that your user will interact with is the top layer, an interface.

In order to get to that final, delightful experience as fast as possible, developers can go about it two ways. Either you build every underlying bit yourself or use pre-existing building blocks, provided by companies that focus on specific verticals and combine them with a great product experience.

In the early days of the automobile industry, car companies used to produce every single piece of a car in-house, including tires. They owned rubber plants and built entire cities around them. As a result, tire design was progressing slowly and production was often inefficient, due to a lack of deep specialization. So what happened? Independent tire companies came up with synthetic rubber, producing better-designed tires more efficiently than the companies focused on building an entire car ever could. Focus is important.

We’ve seen the same process in software. It has accelerated dramatically in the last few years with the advent of Internet APIs and SDKs, bringing efficiency and quality of building blocks up, while shortening the development cycle for products drastically.

Today, no one in their right mind would build an entire maps stack from scratch to show a listing or car on a map. Very few people would build an entire payments stack from scratch just to collect a payment. These are just a few examples of problems that are either hard to solve, regulated and full of secrets or technologically very challenging. Similarly it makes no sense to build an entire communications stack from scratch.

These building blocks are enabling many of the new product experiences we are seeing today. Imagine AirBnb without listings on a map. Imagine Foursquare without a map. Imagine having to hand out cash for every Uber or Lyft ride you take instead of just getting out of the car. Imagine not being able to pay a seller directly on Kickstarter or Etsy.

We can’t wait to see how developers take advantage of all the new building blocks and the experiences they will create.