Sustainability in software development means including ecological responsibility as an independent quality characteristic in development decisions. The Pink Index evaluates products in seven dimensions: Manufacturing quality, necessity, frequency of use, longevity, energy consumption, recycling and engagement enhancement. Applied to software, this specifically includes caching, image compression, economical cloud dimensioning and conscious feature design.
Key Takeaways
- The Pink Index evaluates products not only according to CO2 equivalents, but also in seven dimensions: Manufacturing, Origin, Necessity, Frequency of Use, Longevity, Energy Consumption in Operation and Engagement Strengthening.
- Training AI models yourself consumes considerably more power than running them later, which is why companies should critically examine whether their own GPU cluster is really necessary.
- Computers consume substantial amounts of energy even when idle, so conservative dimensioning of the execution environment is better from a sustainability perspective than generously provided, underutilized nodes.
- Many software features are hardly or never used, but consume computing power, memory and transmission capacity permanently, which makes them an avoidable sustainability problem.
- A target image that seems unattainable prevents the first step from being taken at all: Small improvements by many stakeholders have a greater overall impact than perfect solutions by a few.
Green IT and Green by IT are two different levers
Anyone discussing sustainability in software development usually ends up talking about green IT: building software in such a way that it consumes less memory and less power so that data centers draw less energy and less data travels over the line. This makes sense, but only covers one side.
Green by IT means something else. This is about the question of what software can do for sustainability as a whole. Dominik Rost and Marcus Trapp see the greatest potential here.
A simple example is fleet planning. If software helps to save a car, then this has an effect on the environment and on the wallet. You don’t have to discuss such win-win cases for long, you just do them.
What the Pink Index measures
The Pink Index evaluates a product over its entire life cycle instead of just calculating a single key figure to the eighth decimal place. Pink stands for “pragmatically precise information on sustainable consumption” and is part of the Full Flamingo company.
The usual approach in Germany drills deep into CO2 equivalents: Manufacturing, packaging, delivery, component supply and raw materials. This is thorough, but leaves many other dimensions under the table.
The Pink Index reverses the logic. Instead of becoming more and more precise in one dimension, it looks at all dimensions with pragmatic precision. This includes issues beyond CO2:
- Do you really need the product, or is it a convenience or luxury item?
- How often do you use it, what is the frequency of use?
- How durable is it, is it a disposable product or does it last a long time?
- How much energy does it need not in production, but in ongoing operation?
- What happens at the end, is it recycled, dismantled or passed on?
Dominik and Marcus call a separate, almost esoteric dimension “strengthening commitment”. It describes how a product helps you to behave more sustainably yourself. A water-saving shower head is an example of this: even if the manufacturing process is not ideal, you save water every time you use it.
How the index comes into purchasing
Full Flamingo does not operate its own store or a public computer, but is integrated into existing stores. The sustainability rating of the specific purchase appears in the shopping cart area, where insurance for electrical appliances is offered, for example.
The rating shows the seven dimensions of the Pink Index with a traffic light system. This gives you an immediate impression of how sustainable your purchase is.
An amount is linked to this rating, roughly between 4 and 6 percent depending on the purchase. You can donate this amount to a regional campaign organization that promotes sustainability locally. The whole thing is opt-in, without subscription and without obligation.
The regional connection is the goal, not the starting point. There are thousands of repair cafés, urban gardening and food sharing initiatives in Germany, often without visibility and without a common organization. What they all need is money. Dominik and Marcus see the biggest lever for this in daily consumption.
Putting your own development process to the test
A sustainability company must also apply its own standards to itself. This is precisely why Dominik and Marcus apply the logic of the Pink Index to their own software development. They see themselves as a tech company for sustainability, so looking inwards is part of this.
Applied to software, production becomes everything that happens at development time. A lot of it has nothing to do with code to begin with: Does the company use real green electricity? In Germany, there are only around ten providers that really supply genuine green electricity. Are there lights on everywhere in empty offices at night?
Closer to the technology, there is the question of the test systems. Does every single commit have to go through the entire test infrastructure, even if only the readme has been changed? This may make sense from a testing perspective, but not automatically from a sustainability perspective.
Training AI models yourself is a question of power
Training your own models costs an enormous amount of electricity. AI already requires a lot of energy in its application, but training the models requires far more.
Before everyone sets up their own GPU cluster, it is worth asking whether this is really necessary. The reflex to set something up yourself because everyone is doing it is expensive from a sustainability perspective.
Why conservative dimensioning is often better
Computers consume substantial amounts of energy, even when they are doing nothing. It is therefore cheaper to utilize machines to capacity than to let several nodes in the cluster run idle with a low base load.
Cloud providers make it easy to book the next largest CPU or more memory. Developers like the buffer because then everything runs smoothly. From a sustainability perspective, the opposite approach is better: first dimension conservatively, then add more if performance problems actually occur.
The same applies to unused hardware. A residual budget at the end of the year quickly leads to computers that nobody knows whether they will be needed.
Every feature costs energy over its entire service life
Many features that are built into software are hardly or never used. Studies indicate this. Once built, a feature usually stays in, even though it takes up CPU, memory and data transfer.
This also applies to technologies and data. Do you really need an additional Redis next to it, or is something that is already in use sufficient? Do you need to collect as much data as possible in data lake style because you might find an interesting correlation for the dashboard later? Every amount of data collected, transported and stored costs energy.
Save a lot with little effort: Data over the wire
Between server and client is not a dumb line, but a chain of DNS servers, routers and firewalls. Each of these devices must be operated and process any amount of data. The less that goes over the line, the better.
At this point, small measures quickly have an effect:
- HTTP caching is implemented with manageable effort.
- Image compression and responsive images significantly reduce the amount of data transferred.
- Static HTML pages often replace a fully-fledged content management system.
The static page is a good example of superfluous complexity. Many business websites do not need a CMS with a database. In one case at Fraunhofer, the only reason for a CMS in the end was that each branch had different opening hours.
Web standards today are powerful enough to deliver a good user experience with HTML and CSS. A static page is fast, secure and doesn’t need a lot of JavaScript.
What happens at the end of the hardware lifetime
The last dimension asks where a product goes when it is dismantled. In IT, this can be seen in the piles of old notebooks that accumulate because new devices have been purchased, even though the old ones would still meet the requirements of normal day-to-day business.
Simply disposing of these devices is the worst option. At the very least, they should be recycled properly. A second use is better: donate them to schools or associations or give them to the Global South via companies such as Laptop.org, which transport, repair and refurbish the devices in a CO2-neutral way.
The same idea is behind the sharing economy and the circular economy. A garden scarifier is used once or twice a year, but can be found in many basements. Such products are suitable for borrowing. Second-hand platforms give things a second or third use as soon as the offer and size are right.
Sustainability is a quality characteristic with trade-offs
In software development, sustainability belongs alongside the other quality characteristics of a system and should be explicitly weighed up. It’s not about doing everything immediately, but about considering this aspect in the first place.
Not every measure clearly makes sense. Relocating workloads to a region of the world with green electricity sounds good, but it costs a lot of effort and means transporting data and logic once around the world. Whether this is worth it in the end depends on the context. There is no cookie cutter that suits everyone.
The first step is more important than a perfect target image. If you set up an unattainable ideal, you make sure that no one goes anywhere.
Each and everyone, if there is a small contribution somewhere, then we will all be helped in the end.
Marcus Trapp
Full Flamingo’s own homepage shows that the principle also works on a small scale: 92 images, which are not small but generously displayed, come to a total of 2.72 megabytes. Thought through early on, easier to maintain later.
