Reflections on "Performance and Sustainability" at QCon London 2025

I had the privilege of hosting the "Performance and Sustainability" track at QCon London this year. It was my first time hosting a track, and I was incredibly fortunate to have the following talented speakers be a part of it:

• Ludi Akue
• Jade Abbott
• Alex Good
• Sarah Hsu
• Holly Cummins

Now that the conference is wrapped up and I've had some time to process the conversations I've had with attendees and the various talks I've seen at the conference, both within and outside of my track, I had some thoughts I wanted to write down (and share since I'm "learning in public"! 😉).

The perception of sustainability as a 'niche' concern persists in the tech industry

One attendee summarized some of the challenges that folks face in getting their teams and wider organizations to prioritize sustainability efforts well - that it's still seen as a "niche" interest and topic.

This was reflected in the fact that a significant number of questions were asked about how to get buy-in from other engineers and, in particular, the leadership of a company to start measuring emissions or incorporating environmentally sustainable practices into software development.

Sustainability efforts are likely to be grassroots-driven by highly motivated individuals in the short to medium term

Barring the introduction of regulations forcing a company to take action on sustainability, efforts to incorporate sustainability into software development is likely to be driven from the bottom up, rather than top down.

That being said, I'm very optimistic about the future of the "green software" movement.

Despite what I just wrote about sustainability efforts likely being grassroots-driven, organizational leaders like Ludi are starting to encourage and incorporate sustainability practices company-wide, and are taking the time to educate their workforces on sustainable practices in order to ensure the whole company is on the same page.

Folks interested and invested in sustainability practices are also highly motivated and engaged. During the Q&A portions of the talks in my track, there was never a shortage of questions. Every speaker also had several folks come up afterwards to ask follow-up questions.

There were also some people who came to one talk in the track who had never heard of the green software movement before. As a result of what they learned in that first talk, they ended up going to additional sessions in the track because they became interested in the topic.

I think what this will mean is that in the longer term, incorporating sustainability into the software development lifecycle/process will, to paraphrase Ludi from her talk in the track, "just be the way we do our jobs."

The inability to get precise data is hindering sustainability efforts

Due to how difficult it can be to get precise carbon emissions data on the software we run (as noted by Ludi and Sarah in their respective talks), it leads to struggles in sustainability efforts on two dimensions:

1. Software engineers don't think it's worth the effort to take essentially inaccurate measurements on the carbon emissions of the software; and
2. Business leaders want concrete numbers, which are currently impossible to get for a variety of reasons (cloud providers being opaque about this being one major example).

One of Ludi's takeaways was for us to collectively push our hosting providers to be more transparent here so that hopefully, in the longer term, we'll be able to be more accurate.

In the meantime, we'll need to be ok with approximate numbers and using proxy measurements (as Sarah proposed in her talk), and not let the lack of precision get in our way towards beginning to measure the carbon emissions of our software.

There's a gap in understanding about the various meanings of sustainability and why they're important

Jade's talk highlighted that the meaning of sustainability can apply to other things outside of an environmental context. Specifically, it can also be applied in a cultural and economic sense.

Economic sustainability is straightforward to explain and get buy-in on (i.e. the old adage of "don't put all of your eggs in one basket" is an example of this). But cultural sustainability?

For folks living (or have lived) in a non-Western world context, I imagine the value of this (that is, cultural and linguistic diversity) is obvious to you.

In contrast, for those who have only experienced the Western (and more specifically, the North American/Western European context), it may not appear obvious as to why cultural and linguistic diversity and sustainability are important.

When the Western world's culture drives the development of powerful new tools to solve the problems that it deems worth solving in the way that it views as the best way to solve those problems, this means that large segments of the global population are left out (what Jade called the "global majority" in her talk).

This translates to those folks becoming technologically underserved and, at times, exploited by the companies developing and promoting these new tools.

Alternative ways of thinking and relating to the world are captured in different cultures and languages. Jade brought that point home in a slide that said "every 2 weeks, a language dies and, with it, a way of thinking".

In spite of recent trends spurred on by a certain political climate, the tech industry seems to still generally accept that diversity is an important ingredient to success, as the best solutions to problems come from a wide array of perspectives.

Despite that, I overheard some attendees after Jade's talk express confusion to each other over the value of cultural and linguistic sustainability.

It seems that there needs to be more awareness raised on this topic so that software engineers understand that sustaining various cultures, languages, and their ways of thinking and relating to the world is part of the same diversity of thought, experiences, and viewpoints that mean drastically improving the odds of finding the best solutions to the problems we're trying to tackle in the world.

Those are all the thoughts I have right now. I hope to share recordings of the talks I'm referencing soon but I think it'll still be another few months for them to become publically available.

In the meantime, you can check out the abstracts of the talks here, and from the speaker profiles, you can find the various social media pages and websites of the speakers themselves to learn more about the topics they've spoken about at QCon London.