To TOX or not to TOX

How technical and operational excellence is achieved

Elli Engineering
Elli Engineering
4 min readApr 13, 2023


(illustration made by Lukas Hanke)

In our very first blog post, we introduced you to Elli’s guiding principles for achieving engineering excellence. In this article, we delve deeper into one of the practices our engineering teams use on a per-sprint basis to maintain a high level of code quality and to upskill technically. It’s a practice we call “TOX”, and it stands for “Technical and Operational Excellence”.

What are TOX stories?

TOX are driven from engineering teams, and can be seen as a parallel stream to feature development. Each team dedicates some proportion of the time to work on such tasks. The amount of the time spent for TOX depends on the team and their priorities for the current sprint.

The time spent on TOX stories depends on the team itself. (illustration by Lukas Hanke)

Such topics usually come to the team from the Tech Lead role, however all engineers are encouraged to initiate a TOX. The key is to understand what is included in such a task.


TOX is not about repaying technical debt that has been introduced as a consequence of feature pressure or to fulfil the “Definition of Done” for business requirements tasks.

There are guidelines about Do’s and Don’ts when creating TOX stories. (illustration by Lukas Hanke)

Examples of TOX topics

  • Minimising the risk of technical debt
  • Improving developer’s experience
  • Knowledge sharing within Elli
  • Improvements in the CI/CD pipelines
  • Testing improvements (introducing black box testing for example)
  • Upgrading software package dependencies
  • Automating the repetitive

Examples of non TOX topics

  • Product improvements
  • Fixing bugs
  • Tech debt that has been deliberately accepted by feature pressure or tight deadlines
  • Operational tasks that are vital to the product
  • Supporting existing / implementing new internal business processes
  • Supporting customer care
  • Preparing presentations / demos for sprint reviews
  • ISO related topics

The gist of it

“Leave your code better than you found it” — The Boy Scout Rule.

(illustration by Lukas Hanke)

The main point of following this principle is to maintain the quality and sustainability of the codebase. Additionally, we initiate TOX stories for several other reasons:

Improving CI/CD experience

We want to continuously work on CI/CD automation and improve our pipelines. This helps us in identifying and fixing bugs early in the development process. It also supports us in speeding up the delivery of software updates and new features to our users. By automating such repetitive tasks, it results in cost savings for organisations and ensures that the software being delivered to users is of high quality.

Improving developer experience

As engineers, we also want to boost our productivity. Improving our experience enables us to work more efficiently and produce higher quality code in less time. Delivering faster and better reduces the likelihood of costly errors and downtime. Additionally, a positive developer experience enables us to collaborate better with other team members.

Codebase housekeeping

In order to improve the quality of code, we focus on refactoring to make it more readable, maintainable and scalable. In this way, we reduce technical debt and increase efficiency of future development.

Knowledge sharing

Last but not least, we highly embrace the power of knowledge sharing. TOX stories are also used to initiate lightning talks so that we learn more from each other about a new tool, technology or anything else that promotes clean architecture and code.

To Sum Up

The practice of “TOX” or “Technical and Operational Excellence” is used by engineering teams to maintain high code quality and to upskill technically. TOX stories are tasks that are not directly related to feature development, but rather focus on improving developer experience, automating tasks, minimising technical debt, improving CI/CD pipelines, and sharing knowledge. The article emphasises the importance of maintaining code quality and sustainability through practices like TOX and refactoring, and encourages engineers to continuously improve their skills and productivity.

Learn More

At Elli, we are always in search of improving the way we work together as a team. If you are interested in finding out more about how we work, please subscribe to the Elli Medium blog and visit our company’s website at! See you next time!