I'm David Llewellyn-Jones and this is my homepage. I'm a software engineer at Jolla, who's also interested in programming, security, privacy and graphics. I occasionally crave adventure and a good thunderstorm. You might be interested in my software, my research or my random musings.

Want to know more about me? Here's a personality sketch written by a psychologist when I was in school.

“David is of high intelligence, although lacking in true creativity. He has a need for order and clarity, and for neat and tidy systems in which every detail finds its appropriate place. His writing is rather dull and mechanical, occasionally enlivened by somewhat corny puns and by flashes of imagination of the sci-fi type. He has a strong drive for competence. He seems to have little feel and little sympathy for other people and does not enjoy interacting with others. Self-centered, he nonetheless has a deep moral sense.”

Wow. Harsh. But disturbingly accurate.

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21 Nov 2020 : Waste data dump #
Another of my fortnightly waste data dumps just went up. The daily average for this fortnight was 176.3g, which looks okay to me, but is actually slightly higher than my 2020 average so far of 171.0g. Close enough, I think. Proportionally it seems my returnables (that's plastic bottles and aluminium cans) were higher than usual. That's a product of boredom during lockdown, which I've been trying to stave off with unusual drinks. I'm not sure it's working, if I'm honest.
8 Nov 2020 : Waste data dump #
It's time for my fortnightly waste data dump again. The average for this period is 168.1g per day, very slightly more than last time, but still a good result. In fact it was pretty similar to the previous results even in the breakdown. Slightly more plastic and general, slightly less paper.
1 Nov 2020 : Site backend update #
There was a small update to the backend code for the site today. I found a couple of bugs over the course of the last week. First the wildcard rss feed that's supposed to include every addition to any list on the site was showing only the news items. Second the botstop check (a simple CAPTCHA used to prevent bots from accessing certain pages) was failing on pages that combined a URL rewrite with a redirect. Both of these should now be fixed.
24 Oct 2020 : Waste data dump #
My fortnightly(-ish) waste data dump has just gone up. The daily average is 161g/day, which is pretty good for me. What's more, the largest category is compost, which I suspect is the least environmentally damaging out of them all. In related news I've taken the luxury of getting a couple more bins (paper and plastic) to help with this process. So I'm pretty happy with things this weekend.
10 Oct 2020 : Waste data dump #
It's been a good fortnight on the waste front, probably due to the fact I'm now spending my daytimes in the office rather than at home (although, looking at the trends, I may have to change back to home-working in the not-too-distant future). My daily average over the last 13 days has been 120g/day, which is less than half my 300g daily target. I can't say I'm not pleased. Having said that, looking at the details more closely reveals a more regressive trend. The big shift has been a decrease in compostable waste, while my general waste actually increased slightly on my previous readings. General waste being the most damaging, that's not such a good shift. The numbers that make the difference aren't huge, so it's probably just a fluctuation, but maybe I should be thinking more about category-specific targets in future, rather than combined targets.