This is part 3 of a 4-part series of articles based on discussions at the LondonCD meetup group on 12 June 2017. The other posts are linked at the end of this article.

Applying the principles and practices of Continuous Delivery for new software is fairly straightforward (at least, until you deal with data and databases). However, existing “legacy” systems that were built without many automated tests and without much concern for repeatable deployments of discrete functionality pose a challenge for moving to Continuous Delivery.

Here is what we discussed:

1. Manual testing gates can be addictive “like crack”
2. Testing for legacy systems should be risk-based, not using blanket end-to-end tests.
   1. Risk-based testing prompts a conversation with stakeholders – useful in itself.
3. A proof-of-concept system turns into “instant legacy” if it is put live with no time for improving operational readiness.
   1. In Working Effectively with Legacy Code by Michael Feathers, the definition of “legacy code” is effectively just “code without tests”.
4. As ace tester Dan Ashby writes in his excellent article Continuous Testing in DevOps , the role of the tester can be re-focused away from manual testing and towards more valuable things like:
   1. Assessing the supportability, operability, and security of the software
   2. Testing User Stories – are the tasks/stories even viable or sensible?

Other posts in this LondonCD series

On 12 June 2017 we had a London Continuous Delivery meetup at Endava in London. We used a modified form of the Open Spaces format for the meetup with less initial open discussion and more guidance/suggestions on discussion topics (based on past experience with events like PIPELINE Conference, this “accelerated” approach is easier for people new to Open Spaces).

Some good discussions came out of the evening:

1. Continuous Security in Continuous Delivery
2. Difficulties and Solutions for Continuous Delivery of Databases
3. Continuous Delivery for Legacy/Heritage Systems
4. Things I Don’t Like About Continuous Delivery

Thanks to everyone who attended, and for Endava for hosting!