Living with Clearing software

The UK university clearing process brings together all the features you don't want in a software project.

The software isn't used for 8 months of the year, then, on two specific days, thousands of people need it. And it has to work. Any bugs, performance problems, or downtime, and you may as well not bother. You can't try again next week.

Clearing is a way to match up university applicants to courses. Universities make offers based on predicted grades. A-Level students get their actual results at the same time, and that's when the scramble starts. From 8am on an August morning the university phone lines and websites open. Students who missed their offer grades apply, and universities compete for the best students. I'm simplifying.

The software for clearing has to collect applications, support the admissions workflow and help them make fast and accurate decisions, integrate with telephony, ingest from UCAS, predict bums-on-seats, and a ton of other things.

Given the stakes, it might be tempting to lock things down: after testing, no software changes, no deploys.

That doesn't work. Requirements come in at the last minute, and during the heat of clearing, weird never-before-seen situations come in. If you can find a way to improve the workflow, you judge the risk, then do it. You have a few hours to be useful.

What has worked:

External functional and load testing keeps you honest
For the last few years, I've worked with Zoonou. There's a good fit to their "Black Friday" test experience, and their ability to retain knowledge about the app year on year.

Having the confidence to make changes
A good set of automated unit and functional tests, deep knowledge of how the software hangs together and what it's supposed to do (harder than it sounds), fast feedback from users, peer and/or LLM coding and review.

Reliable deployments and visibility
Automatic fast deployments and scaling must be the norm now. Northflank have not let us down, and having their support team and founders in our Slack has been great for our well-being.

Still, with all that, as you watch user numbers ramp up, a monitor or two full of graphs, you think: "what have we missed? What is going to bite us?".

As the minutes pass, you start to relax. If you've survived by 11am, you're going to be OK.

I had a boring clearing. That's the goal.

* * *

That should also be my last clearing, assuming the software hand-over goes well.