Environment Variables
Building Green Software
April 11, 2024
In this episode of Environment Variables, host Chris Adams introduces the co-authors of Building Green Software - Anne, Sara, and Sarah. Through candid discussions, they explore the process of writing about green software development and highlight key insights gained along the way, touching on the interconnectedness between sustainability and existing best practices in software engineering, and emphasizing that embracing sustainability isn't about adding extra tasks but rather integrating it seamlessly into existing protocols such as security, resilience, and monitoring. Join for a thorough conversation on the lessons learnt writing the newest book on green software.
In this episode of Environment Variables, host Chris Adams introduces the co-authors of Building Green Software - Anne, Sara, and Sarah. Through candid discussions, they explore the process of writing about green software development and highlight key insights gained along the way, touching on the interconnectedness between sustainability and existing best practices in software engineering, and emphasizing that embracing sustainability isn't about adding extra tasks but rather integrating it seamlessly into existing protocols such as security, resilience, and monitoring. Join for a thorough conversation on the lessons learnt writing the newest book on green software.

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Anne Currie: A lot of the best practice in sustainability is often also the best practice in other areas. So it's just one more good reason to adopt best practice in security, in resilience, in monitoring, you know, it's not something you're going "oh my goodness, mate, we have a whole extra thing to do." It's just another reason to do all the things that you should be doing anyway.

Chris Adams: Hello, and welcome to Environment Variables, brought to you by the Green Software Foundation. In each episode, we discuss the latest news and events surrounding green software. On our show, you can expect candid conversations with top experts in their field who have a passion for how to reduce the greenhouse gas emissions of software. I'm your host, Chris Adams. Hello, welcome to another episode of Environment Variables, where we bring you the latest news and updates from the world of sustainable software development. I'm your host, Chris Adams. We talk about green software a lot on this podcast, but if you're coming to this from, typically, a background of software engineering, it can be hard to figure out where to go next after you've done some of the kind of free training or seen a few talks online. So, you might ask yourself, "how do you build green software?" Fortunately, today, I'm sharing a podcast with three women who've written a book called precisely Building Green Software. I'm joined by Anne, Sarah, and Sara. So, before we dive into this and talk about how you build a book called Building Green Software, I just want to give a bit of space for my co-host this week to come on. Anne, is it okay if I give you the space to introduce yourself and then hand over to the next of your little gang?

Anne Currie: Absolutely. Yes. So my name is Anne Currie and I am the CEO of a green training company called Strategically Green. And I'm also one of the co chairs of the GSF community working group, and I am the lead on the GSF's new Maturity Matrix project. So yeah, those things, and I'm one of the co-authors of building green software along with, and I will hand over to Sara.

Sara Bergman: Hi, my name is Sara Bergman, or Sara Bergman, Bergman. I never know how to say it in English because it's so different from the Swedish. But yes, I am a senior software engineer at Microsoft, even though I'm currently on maternity leave, hence why brain is not fully switched on, and one of the co-authors of the book Building Green Software.

Sarah, over to you.

Sarah Hsu: I've been waiting for that sentence for so long. Sara and myself have been working together, but we never really shared a stage. So Sara over to you, or Sarah over to you, has been our dream for a long time, and now it's finally happening. But anyway, hello everyone. My name is Sarah Hsu. Similar to Sara, my surname is actually pronounced very differently with an English accent.

So yeah, Sarah Hsu, it's fine. So currently I'm a site reliability engineer working for Goldman Sachs, but I'm also one of the co-authors of the Building Green Software book. And this is why we are here today. I'm also the project chair for the Green Software course that we recently launched with Linux Foundation a few years ago, and we currently have over 70 000 completion, which is amazing.

But yeah, anyway, that's me.

Chris Adams: Cool, thank you, Sarah, sara, and Anne. I'm saying hello from Berlin and Sarah Hsu, you're calling from London.

Sara, whereabouts are you calling from today?

Sara Bergman: I am in Oslo, Norway. So yeah, I am Swedish, but I live in Norway. This does not matter to anyone who lives south of Denmark, but for us Scandinavians, it matters a great deal.

Chris Adams: Cool, thank you. And Anne, where are you calling from today as well?

Anne Currie: I'm calling from London as well. So we're not quite as international as all that.

Chris Adams: Oh, well, it's not bad. Four different cities in three nations isn't, isn't too bad, I suppose. All right. Okay, so if you're new to the Green Software Foundation podcast, my name is Chris Adams. I'm one of the policy working group chairs in the Green Software Foundation myself. I'm also the executive director of the Green Web Foundation, a Dutch non-profit focused on reaching a fossil free internet by 2030. And before we dive into what it's like writing books about green software, here's a quick reminder that everything we talk about will be linked in the show notes on this episode. And because we're a software engineering podcast, the transcript will be available on GitHub in markdown format. So if there's any typos or there's corrections, then we do accept pull requests.

And if there are pull requests that are accepted, we'll then credit you and shout you out in the next episode. All right, then. So, itooks like you're sitting with us comfortably, Sara, Sarah, and Anne. Should we get into it and talk a little bit about writing green software and or writing about writing green software?


Anne Currie: Absolutely.

Chris Adams: All right. Okay. I'm going to hand to you, Sarah, first. If I understand it, this is one of, your first book writing about green software. So maybe you could just talk a little bit about how you found that process, writing about, say, a developing field like this.

Sarah Hsu: Yeah. It's my first time writing a book and it's also my first time appearing on a podcast. So maybe we can make another episode on this experience. I'm joking. So what was it like writing a book on green software? Honestly, I don't want to sound too cheesy, but it has been a really fulfilling experience.

And why is that? It's because finally I can use what I'm good at, which is software engineering, and use what I've been training for the past seven to 10 years to have a positive impact on the environment. And it just, it's great to see that ripple effect from something I'm good at and instead of just individual actions.

So I feel that really, really close to my heart. And of course that Anne and Sara made, they're not, they're more than just the icing on cake. They're absolutely integral to this entire experience. I've always admired them since I first met them three years ago. And working with them has taught me so much.

Yeah, couldn't have asked for better co-authors. And, and thankfully we all share similar humor. So when one of us put a joke or put a pun in a book, it doesn't get like, "this is not funny," cross it out. So I think that's also another icing on the cake. Yeah. But yeah, hopefully that's not too cheesy of an answer... 

answer but 

Chris Adams: No, it's okay. It's okay to be genuine if you've enjoyed working with other people, especially if you're doing something you believe in. Absolutely. All right. So that's the skinny from someone who's basically been writing books like this for a while. Anne, this isn't your first rodeo, you've written a few other books.

And I know that you, and we've spoken a little bit about all kinds of sci-fi books before, so maybe you could, I could just touch on you about maybe some of the differences between writing about wacky sci-fi or writing about things when you're, if you forgive the term, at the coalface of software development trying to figure out what to do next here.

Anne Currie: Yeah, that's a good point. So this is my tenth book, eight of which though were sci-fi, were futuristic sci-fi, but kind of like more speculative fiction than hard sci-fi. So it was all kind of surprisingly similar to writing an actual book about stuff that's happening now. But oddly enough, writing the fiction is much easier because you get to make it all up.

Whereas, although I try not to make it up, I try to keep it quite, quite, quite,

realistic. It's hard sci-fi, Yeah. but the book was much more difficult because the book, I mean, I think this is true for all of us. It was really important that we got everything right and we, and we phrased it right and we made it so that people could read it. Which I also want to do with my books, but they aren't quite so important, if you know what I mean. This feels like an important book, or we need there to be an important book, so hopefully this will be the important book, because if it isn't, then it'll be quite a long time before there is another one.

It's a lot of work, writing a book.

Chris Adams: I can definitely concur with that. Alright, so, one thing I didn't mention was that this was actually published by O'Reilly, who have some form writing about sustainability in this field. There was a book by Tim Frick, in the mid 2000s, called Designing for Sustainability, which was focused on web. But as I understand it, this has more of a focus on parts of cloud, perhaps, or some of the other practices. Sara, you've been working with cloud for a good few years now. Maybe you could talk a little bit about what actually the content covers inside green software, because it's quite a wide term and there are ideas like web for sustainability. Maybe you could just, maybe give a high level on some of the areas you focus on, then we can talk a little bit about how you folks work together remotely.

Sara Bergman: Yeah. Sure, sure. Yeah. So definitely if you run on cloud, we have a lot of content for you, but even for people who have their own data centers or on prem and you're allowed to call like a few servers in a closet, a data center, as far as we're concerned, there are definitely material for those people as well. We all come from a more backend point of view, but there is.

Web and front end content as well. Some of the points are on a much higher level than this applies only to you if you deploy to this specific type of machine. We tried to go broader, so it's really for anyone who writes or works in the software industry. Not just for, for the engineer, but for someone who is in a role that's not so directly linked to, to code.

We focus a lot on ops as well. So if you are on that side, there is a lot of good content for people like that. And that was really important to us. We come from slightly different backgrounds and we don't want to exclude anyone. That was one of the things we talked about really early on in the process.

You should pick this book up and feel like there is something for me here. And that's been really fun, I think, to sort of go broader than maybe you do in your regular, like, nine to five job.

Chris Adams: Okay. All right. Thank you for that, Sara. So, I now. If I may, I'm just going to touch on a couple of things that you spoke about there. You spoke about the idea that you're writing a book for a number of different audiences, so it's not just for people who are like optimizing code. It's not just about green code, there's maybe aspects of ops as well and things like that. And, given that you're not all in the same space, and given that O'Reilly has quite a, like, established kind of setup for writing books, maybe you could talk a little bit about how you wrote this. Like, was it like, you're using a bunch of GitHub together? Was it Google Docs? Or is there some kind of magic platform behind the O'Reilly firewall that you might be using to keep track of this stuff?

Because I've never, I've never understood, and we're a bunch of engineers here, or at least coders here, because I'm curious, I'm interested in it, and like, it seems a bit weird to maybe use like email versions of Word around to write a book about code, for example.

Anne Currie: Yeah, it was all Google Docs. Well, well, one of the interesting things is O'Reilly have a lot of different options for how you're going to do it. So they have a kind of, there are kind of GitHub integrations where you can do all through GitHub. But we decided to do it all on Google Docs because we were so remote. And in fact, we've only met all the three of us in person once before. So it was all, all had to be remote. So we would use Google Docs. And I think it went pretty smoothly. That was quite easy. I don't know what you two thought.

Sara Bergman: Yeah, I agree. And especially because all of us have been traveling at some point, or some of us traveled quite a lot, I've had, been very pregnant and then had a baby. And there are circumstances where you don't want to boot up a laptop and like sign into a Git repo. Like that's second nature to some, but sometimes it's very convenient to be able to do it from your phone at 3am, if that's when you have the time.

Chris Adams: All right. Okay then. So that gives us a bit of idea of like how the sausage was made, so to speak. All right, then. Anne, I'll put this to you first and then see who else wants to bite. Last time we were speaking, Anne, you were, we were talking about, I think, lasers from space as a way to power data centers, about whether that's a good idea or a bad idea. And I learned a bunch of things about there. So are there any particular things you learned about green software along the way when you're writing this book? Because you can't, you know, you can't be the expert automatically then, and it's a very, very fast moving field. So were there any things that kind of leap out at you or that you were surprised by as you were writing this, that you had to kind of change your opinion on or rethink perhaps?

Anne Currie: Well, probably my favorite chapter to write, which was, was the one that I had to do the most work on, the most research on, we only decided to add later on in the course of the book, which was the networking chapter. Because I was quite interested in what, how does networking fit into green software? You know, is it, where is all the electricity being burned?

You know, and I've, the, the most interesting thing I think in that was I interviewed a whole load of people and I did a lot of reading of papers and things like that to find out what was going on. And the interesting thing for me, I think was the last mile, comparing how good or bad, or green or ungreen all the ways means of connectivity are. So, finding out that that fiber is by far the best by a long chalk actually. So fiber is fantastic. So the backbone is pretty good. The Metro, which is what takes your data across cities, that's pretty much all fiber these days, it's pretty good. And The Last Mile, if it's fiber, it's pretty good to your house. That's the best, followed by Copper. Copper is actually pretty okay, if you're still, I'm still on Copper here, and don't, you know, don't feel too badly about Copper. But once you move into wire free stuff, then Wi-Fi isn't too bad, but 3G is absolutely terrible. 2G is terrible. 3G is better than 2G was.

4G is much better than 3G was. And 5G is much better than 4G. But one of the things that interests me about it is that the mobile generations are a classic. Something we talk about a lot in the book is Jevons paradox, which is the idea that as things get more efficient, you use more of them or to a certain extent, you don't use more of them because the, well, 

they, you, 

Chris Adams: The savings can be eroded by the increased amount of use in absolute terms. That's what you're getting at, right?

Anne Currie: Indeed. Yes. Yeah. And 5G, I would say is the classic example of that, which is it's much better than 4G, but you know, people didn't invent it for that reason. They developed the efficient 5G because they wanted us to be doing a lot more stuff on mobile devices, and we will use it. The whole point is for us to do more stuff on mobile devices, more mobile gaming. And so, yeah, 5G is vastly better than 4G, but it will drive massive increase in the use of mobile. And mobile is very energy intensive compared to a landline or Wi-Fi. It's different use case.

Chris Adams: So there's one thing I want to just check on before I kind of hand over to one of the... Can I say one of the Saras, or one of the... Sarahs, Saras, all right, yeah. I'll hand over to you if there's anything that you found surprising. So when you're saying better, you're talking about in terms of energy use per gigabyte transferred here. That's your use, like it's efficiency that you're referring to there, right?

Anne Currie: Bits per watt or watts per bit is the industry term for it. And it's something they really do focus on a lot. And the interesting thing is, yeah, I mean, obviously networking is there because everybody wants to do more networking. There's, there's so much untapped demand, which is a classic Jevons paradox issue, really.

Chris Adams: Well hopefully the fact that we've got a bunch of dark, do we still have significant amounts of dark fiber from previous dot com booms and busts where we've got all this stuff available for us to use? Surely that's one thing that we have been able to pick up on, right? Right,

Anne Currie: Well, yeah, there certainly would have been, but to be honest, the past is of no use to us really. It's all the stuff that's been, we're just still laying cable at an unbelievable rate to handle people's, the desire for streamed content.

Chris Adams: So there's an aspect of embodied carbon that we need to be thinking about as well then. So that's one of the things we've learned. Alright, I'll open the floor to, yeah, Sarah Hsu, in London. Are there any particular things that surprised you when you were writing this or caused you to kind of change your mind or think, "Oh. This is probably something we should be spending a bit more time thinking about," for example.

Sarah Hsu: Yeah, so we have a chapter called Core Benefits. And our initial idea was to basically examine green software from different perspectives in software engineering. We have like security, we have reliability, resilience we've performance, data, all that. But while we were writing that chapter, we realized, "hey, actually, this is all very important, but one thing that we're seeing is, because of what's going on around the world, there's so many other things going on. People really are not taking green software as seriously as maybe say 2021." So we actually wrote a chapter on like how we can help our readers to convince others that green software is not as difficult as it's thought out to be, and we came up with like a three bullet points on like how you can convince others. But most importantly, that we want to say in this chapter is that there are so many other knock on benefits from doing other best practices in software engineering already. Green software is not its own ivory tower, like people shouldn't be worried like, "Hey, like everyone is already so overstretched," you don't need to worry about. "Oh, now I need to have a whole new team just to work on sustainability." People who are already very skilled in security, very skilled in reliability, they all can help our software to be more sustainable. I think that's a really strong information we really want to send out there, especially to like the grassroots people and not fail them to be really helpless in the current climate.

So yeah, that's probably quite interesting realization we had later into the book.

Chris Adams: Okay, that's quite an empowering message, and that sounds like, there's a really lovely quote from Adrian Cockcroft, who's leading the Realtime Carbon Project, so he says like "carbon is another metric," and yes, there are other, obviously more metrics that you need to track, but it's not like people in software engineering have never had to measure something before.

So that's one of the things, like, obviously there's things about transparency that can help, but yeah, to an extent, there are lots of transferable skills that can be applied into this domain as well. That seems to be what I'm getting from you on that one.

Anne Currie: Yeah, I mean, I really liked your chapter that you wrote on that. You put something in, Sarah, about "it's not a new work stream." It's, you know, a lot of the best practices in sustainability is often also the best practice in other areas. So it's just one more good reason to adopt best practice in security, in resilience in monitoring, you know, it's not something you're going "oh my goodness, mate, we have a whole extra thing to do." It's just another reason to do all the things that you should be doing anyway.

Chris Adams: Okay, that's a useful framing actually. Sara, I, are there any things that you've learned, that you found, that you want to share, or that you would think would be salient for the conversation here?

Sara Bergman: Yeah, sure. I think, and that maybe goes back to the process is we interviewed people, a lot of people for this book and got their perspective. We also have amazing tech reviewers, and all those people have been very instrumental to the book as well. And, and that's something where I learned a lot from to reach out to people and how willing people are to help and contribute and share their expertise inside the community.

So the community is great. So that's not maybe a hard skill or a hard thing, but that's something that I really enjoyed about the process. And that's something I learned a lot from specifically around the hardware chapter, because I don't work with hardware every day. So. That was a lot of learnings for me.

And actually, I listened to previous episodes of this podcast, for example, the one about the Junkyard Data Center, which is very interesting to include as well as a way to combat e-waste and how big of a problem that is. And then you also get to sort of step outside your bubble and like, okay, but e-waste is surely something that concerns software people, but also other people.

And then you get to realize, okay, but there is lots of legislation around the world working to combat this. And like things are already moving in other sectors as well, which is really fun to see. And then you get additional knock on effects because industries and countries come together to work towards the same goals.

Chris Adams: Okay, all right. Thank you for that, Sara. So, we've, you've written about this, and the thing, you know, when you write a blog post, and as soon as you've done that blog post, you realize, "oh, there's a things, a few things I wish I'd couldn't have put onto it." I imagine it might be somewhat similar when you're getting a book out the door, because once it's out, it's not like you can push updates to a book the same way you can push updates, you know, hotfixes and things. And now the Building Green Software, the book has gone to print, are there any things that you wish you had a bit more time to kind of write about, or that now that you've seen it, go, you know, "oh yeah, we totally missed this," or "here's a thing we should, if I could do that again, I'd spend a bit more time writing about." Sarah, if I can, if I start with you, then I'll kind of go around and then we can round this up perhaps.

Sarah Hsu: I definitely had that same reaction, like two weeks before we were about to submit everything... And this is not a software product. We don't have a process on how to mitigate an incident. What if we wrote something wrong? How do we go about it? I remember just like panicking as well. But it is very interesting, like looking at publishing book.

And like managing a production system. But anyway, I think the things that really, I wish I probably spent a little bit more time on is like in the observability space, like, especially how not just in green software, but like the traditional monitoring metrics and logging really isn't doing what it's supposed to do in the modern software system management, right?

As our system gets more intricate, there's a lot more microservices. Sometimes like if you want to go from one hop, one request all the way for the request to come back to give you a response that can go through a hundred different systems, how do you know exactly where things have gone wrong? And I think I really wish I've spent a lot more time thinking how carbon and how environmental aspects will marry into this space and how do we actually make sure that we are not reinventing the wheel and once whatever metrics, whatever data we are ready, we can slot right into what the world of DevOps and what of SRE is already very good at doing, which is production system management, especially on how to make our system observable, if that makes sense.

Chris Adams: Yes, it does. So what I think I'm taking away from you is that we've got things like spans, and we've got ways to kind of understand the impact of a particular API request or something like that. But when you've got a distributed system, we don't have something like the equivalent to that right now for

carbon, for example. You can't track distributed carbon across all your systems to kind of sum it up.

Sarah Hsu: To find out exactly which system is the trouble one, like, I have a really good analogy. I was writing this the other day, like, you can think of, like, three different elementary data as like a murder mystery, right? Metrics will tell you when someone has died, right? And logging probably will tell you how someone has died, and traces will tell you where this person has died.

So we need to figure out how all these three things will match with, like, the environmental aspect. And hopefully we can have, like, traces that will tell you that's exactly where the bottleneck is happening within our system that, okay, system C.5 is the one that's emitting the most carbon.

Chris Adams: Okay, we're going down a rabbit hole here, but like, we already have all tools like Grafana and stuff like that that give that. Surely we can work out these numbers. This is like a problem that can be solved by,

Sarah Hsu: Yeah. Yeah. But we just need to make sure we are going in the right step. I mean, and not come up with things that ourselves, if that makes sense.

Chris Adams: yeah, that does, okay, all right,

Anne Currie: It is,

well, I'm going to say it is a bit, we'll just spend it, we'll blow all our time talking about this. We need another, we need another podcast to talk about the similarities and differences between carbon metrics and other metrics, because there is a key difference, which we can't talk about now because we're going to run out of time, but we should, we should have that in another podcast. The key difference between carbon metrics and other metrics.

Chris Adams: Okay, all right, that's definitely a thing to dive into, because it's easy to get focused on carbon, and it turns out, yes, we're in a climate emergency, but there's other things we need to be thinking about as well. All right, okay, so we spoke a little bit about what's on your lap next, I suppose, and Sara, you mentioned that there's a baby on your lap, or that's one of the things that you have and you're coming back to. Are there any, like, what happens next now that this is out the door? Because, as I understand it, the book, Building Green Software, is available digitally for people, so you could get it through Safari. But I understand there was quite an interesting approach taken about making this available to a wider set of people.

Does anyone want to take that at all, to talk about the kind of like open aspect of this book? Because this was something which felt quite exciting when I, when I first heard about it.

Anne Currie: Yeah, I'm happy to talk about that. So at the moment, the book is, it's available on the O'Reilly Safari site. So anybody who's an O'Reilly subscription, or if you're a fast reader, you can, you can trial an O'Reilly subscription and read the whole thing. But I wouldn't necessarily recommend that because the book's very intense.

I think if you just sit there and read it end to end, your head will explode. But so it's available on O'Reilly. It's available to buy from all good, well digitally, it's available on the Kindle at the moment, so you can buy it from the Amazon site. And in two weeks, I think it comes out in physical form, so available from all good bookshops. So you can order it anywhere you like and read it in real life that way. Or if you wait a couple of weeks after that, until we actually have time to go around and set something up, it'll also be available under a creative commons license, so under a, it's a, it's a fairly restrictive one.

It's the O'Reilly creative commons license, which is, so you can't take it off and then write your own book, you know, you can't, it's, but you have to attribute this and it's non commercial and it's, but you can read it for free.

Chris Adams: So, source available. You can read it.

Okay, that's, wow, that's really, really exciting then.

Anne Currie: Yeah. That will be available. I'll have it a copy up on my Strategically Green website first, probably.

And then we will, we'll see where else we put it as well. But yes, we insisted on that because it's just so important, you know, it's saying, "we hope this is an important book and it's really important that people read it."

Chris Adams: Great, wow, that's exciting. It's really useful to have something in the, so it's not quite public domain, but it's definitely available in the same way that you can have source available licenses that you can still benefit from and apply there. All right, then. Okay, so we spoke a little bit about some of the things we're covering inside the book, about how you can find this, and when it may be available, and some of the lessons learnt along the way. I've got a question, I have to ask now, like, what comes next, now that we've done that? Anne, I'll put it to you, and then, if anyone wants to take the question after that. So, Anne, you've written a book, or you, plural, have written this book now. Do you just sit in your laurels? Do you just like wait for the royalties to come in or does something else happen after this now?

Anne Currie: If only, if only we could sit in our laurels and wait for the royalties... I don't think writing a book is something you, you ever, unless you're J. K. Rowling, you never really make a, maybe, maybe a film wouldn't be made from this book, but I suspect that's not the case. So, yeah. So the next thing I'm doing is a whole load of training around this, this stuff.

So I'm, I'm doing that through Strategically Green. So started to do some public training and, and one of the things that I'm doing in the public training is, it's focusing on the thing that I would have liked to have put in the book that I didn't. Which is that it's not all bad, you know, there's just enormous benefits.

And one of the reasons why we don't have a whole chapter of like, "Oh my goodness, mate, this is amazing. Why aren't you just stopping and dropping everything and converting your systems to run on renewables? Because it's, you're crazy not to" it's because I don't think a year ago when we started, 18 months ago, when we kicked this whole thing off, that was the case. It wasn't so obvious that renewable power was, was the win that it is becoming. I mean, if you look now somewhere like Spain and Portugal, I'll pick them rather than Scandinavia because Spain and Portugal were doing it the total new tech way. They're doing it with, it's all wind and solar. They're now even in the winter this year, they've had huge, they've had large numbers of weeks when power has been free for the bulk of the business day. So, you know, it's kind of like, this is the dream of humanity that, you know, through, through the ages that we would have effectively free power. And it's looking like that is a possibility, but we will need to change our systems to run on top of it because it's not all the time it's variable. And that's kind of the key message of the book.

But I wish we'd hammered it home a bit more, the wins.

Chris Adams: Right, I'm going to put the question to Sarah Hsu next, but just before Anne, I just want to check on that. When you're doing some research for this, we know that the power, the cost of power changes depending on how available it is. Are there any cloud providers who are making that visible to people yet? Because have you found this? It feels like it's the obvious thing to have to incentivize the use of green power, but it's almost nowhere so far. And maybe you, you might've come across this as well, or maybe the big providers might do something like this because they clearly are making significant decisions about this as well.

Anne Currie: No, I don't, nobody is, but I have spoken to people at most, apart from Google, who speaks to anybody, nobody speaks to anybody at Google, but I've spoken to, spoken to folk who don't necessarily know and have no ability to affect it, but they are aware that eventually we know that the clouds will provide dynamic tariffs. There's no doubt about that because everybody's going to have to provide dynamic tariffs at some point. So, you know, I don't believe that anybody does it at the moment, but I think there's no doubt that it is coming.

Chris Adams: Okay, so not from the big guys, but it's something available coming from somewhere. The one company I've found that is doing this so far, there's a company called TriBuild AI. They're doing this in, I think they're based in Texas, and they're strategically placing things, but the idea is that you can use the power, but not between 6pm and 9pm, when everyone's using power, and that's how they make it like a fifth of the cost of everyone else.

So we are seeing early signs of this, and like, there's examples everywhere outside of technology that we could learn from as well. Okay, all right then, so Anne, that's what you've got on. You've got the maturity matrix to kind of maintain, and the training that you have going on. Sarah Hsu, if I hand over to you. And now that the book's out the door, what do you think happens next? Or what's, what's on your plate after this?

Sarah Hsu: Well, I'm just speaking for myself, but I'm pretty sure all of us are going to be rock stars and go on a tour, go on a speaking tour and book signing tour. So yeah, I think Sara and Anne are doing QCon in April and myself, I'm not speaking this year, but we will be doing like a small book signing there. So it'd be great to see a few folks there.

Myself, we'll be going to Berlin for a conference and then hopefully we'll do some book signing there as well. And one thing I really want to do is I just want to find some observability for who is also really passionate about sustainability and just see what It's just really, really chat it out about like how we can do all this is within observability.

How do we actually make something observable in terms of carbon or like any environmental aspects if that makes sense.

Chris Adams: Yes, that does. If you are not already speaking to some of the CNCF TAG ENV folks, I'm really excited about some of the work they're doing, and they've recently presented some stuff at KubeCon specifically about the observability thing that it's definitely worth chatting about, actually. Okay, and so,

Sarah Hsu: Yeah, definitely.

Chris Adams: And Sara, I'll hand over to you now. What, now that this is out the door, what's on the plate for you, now that you're coming back into the world of, like, software engineering, as opposed to looking after the little one?

Sara Bergman: Yeah, out of the diaper. Well, I guess there will be still be diapers for plenty of time, but yeah, no, going back to work and then being a rockstar going on a speaker tour, like Sara said, so QCon London, which will be very fun. This is the second time only all of us see each other like in person. So very much looking forward to that.

Speaking at NDC Oslo later this year. Also, the Green Software Foundation has a meetup in Oslo, which is very fun. And next, next one of those, I'll be speaking as well. So that would be really fun to like see folk on my own home turf. And yeah, after that, who knows, you know, this was so much fun. Do we do a version two?

I, you know, we'll see. Right?

Sarah Hsu: I think we should, I forgot to mention, we've actually have the book translated to both complex and simplified Chinese. So that's something very, very exciting. I was telling one of my best friend, my best friend was like, "Oh, now your parents don't have an excuse to not read your book," because now, my poor mother will now have to read this book.

Chris Adams: Wow, I did not, that's, that's, well, it's more than a billion people. There's a, there's a readership to, to reach, and people who speak Chinese as a first language probably need to be thinking about the environmental impact of software as well, given it's the second largest economy in the world now, basically, so we've mentioned there's a growing body of resources out there for people to be looking at this. So we mentioned things like, say, some of the free training that's available from the Linux Foundation that people can pick up. And there's a book which we've spoke about, which is Building Green Software by O'Reilly that is going to be available from a number of different places. So Anne, if people do want to, obviously they know about the book, but beyond the book, where should people go if they're interested in what you were talking about or some of the things you're working on?

Anne Currie: Well, at the moment, LinkedIn is, I find, is the new place where all the green chat is happening. But yeah, yeah, LinkedIn. It was lovely whilst Twitter still existed as a thing, and I'm still there, 

Chris Adams: drove it into a mountain, yeah.

Anne Currie: Indeed. It was, yeah, I'm still there. I still find useful things there, but it's not as active as it once was.

So LinkedIn is now my social media hangout.

Chris Adams: Okay, alright, and then Sarah Hsu, how about you?

Sarah Hsu: Similarly, I was never really on Twitter and I'm really glad I have persuaded Anne to move over from Twitter to LinkedIn. I also just can't I do want to quickly mention, we do have an email address that you can reach out to all of us. It's building.green.software@gmail.com. So if you have any feedback, any suggestions, or just want to say... please, please, yeah, just reach out to one of us.

Or if you want more direct response from one of us, reach out to us on LinkedIn. 

Chris Adams: So if you're a retired engineer and you're going to tell people "you should be solving this all with nuclear," obviously, that's the way to, that's the place to send emails to. Okay, alright, please don't do that, actually.

And, Sara, for you, where should people look if they want to keep up with some of the things you're working on?

You mentioned QCon and a few things like that, but if there's a particular URL or website people should look at, then, now is your chance.

Sara Bergman: Yeah, I'm also, also on LinkedIn, missing Twitter. I still hang around, or X, I guess it's called now, and feel sad about what it once was. But no, LinkedIn is the best place.

Chris Adams: All right, then. Well, folks, thank you very much for sharing your time and sharing some of the insights you've learned along the way of building basically the first book about sustainability and stuff which wasn't written by men, because that's actually like about freaking time. That's very, very good. And yeah, lovely seeing you all again. Hopefully, maybe I'll see some of you in London if I get over there or possibly some of you see some of you in Berlin if you're coming over and maybe wonder if you might sign my copy if I can bring it. All right. Thanks, folks. This was fun. Really, really nice seeing you all again.

Sara Bergman: Thank you, Chris. 

Anne Currie: Thank you.

Bye bye.

Sarah Hsu: Bye guys.

Sara Bergman: Bye.

Chris Adams: Okay, take care of yourselves. Hey, everyone, thanks for listening. Just a reminder to follow Environment Variables on Apple Podcasts, Spotify, Google Podcasts, or wherever you get your podcasts. And please do leave a rating and review if you like what we're doing. It helps other people discover the show. And of course, we'd love to have more listeners. To find out more about the Green Software Foundation, please visit greensoftware.foundationon. That's greensoftware.foundation in any browser. Thanks again and see you in the next episode.