Composite services are here

26 August 2021

I’ve written before, back in the before-times of 2015, about the idea of ‘composite services’. It was slightly clunky thinking then, premised on the idea of signing-in to multiple services getting easier through things like oAuth and physical security tokens like Yubikeys.

Covid has made composite services in the UK public sector a reality. Here, for example, are some steps from when I went to get a Covid test earlier this year:

  • Book at test on my local authority’s website
  • Visit a test site operated by the local authority and present a QR code / reference number
  • Scan the barcode on an NHS branded test card
  • Enter some details on GOV.UK
  • Sign in using NHS single sign-on
  • Use a physical test branded at HM Government, scanning a QR code to register the test
  • Get notified of the test result via GOV.UK Notify

Lambeth Council sign at entrance to test site, an NHS test card with barcode and QR code, and a GOV.UK page with a blue NHS sign-in button

The full journey includes interactions with the NHS, central government and local government. It’s a journey through multiple products and services, physical and digital. In a world where you can interact with multiple parts of government in a single transaction, and there are multiple paths through a web of services, there is no single ‘end-to-end’ user journey. Each of those components were are glued together in lots of different ways in other contexts e.g. my local test-centre was a walk-in one, if I’d done the test at home, some, but not all, of the steps would have been the same.

I wonder how public sector design might change if interoperable or permeable services became the north star, rather than end-to-end service design? Similarly, digital identity is often premised on the idea of linking primary keys in back-end systems. Composite services move that linking closer to the end user, in the form of barcodes and permissions.

Composite services also provide a challenge to minimalist ‘just make it work’ design approaches - they ask users to do a bit more work, but with that comes flexibility and (maybe) control.