Challenges

✔ Multi-domain vs multi-lingual 
Like Drupal 7, Drupal 8 & 9 have a multi-domain suite for providing content for multiple domains. The only problem was that the combination of multi-domain and multi-lingual together did not work well. Also, the maintenance on the modules to Drupal 9 compatibility was minimal. So we made Synetic maintainer of the https://www.drupal.org/project/domain_language_negotiation module. This way we ensure that we can provide a good solution for multi-domain projects with multi-lingualism. 

✔ Flexible color palette  
Bejo Zaden B.V. is active in about 40 different countries under the name 'Bejo', but also under other names such as 'Seedcom' in Denmark or 'Premier Seeds' in New Zealand. Some countries differ in terms of branding and corporate identity colors. It also happens that companies are acquired by Bejo under their own name, which then must be incorporated into the multi-domain platform. In the old situation, applying different colors and deviations required a lot of work and adjustments to the theme.   With the Color Swatch module we developed (https://www.drupal.org/project/color_swatch), it is easier to define different color palettes within the same theme. Unlike the Color module in core (which will be taken out of core in Drupal 10) this works with CSS:root property https://developer.mozilla.org/en-US/docs/Web/CSS/:root . 

✔ Generate PDF 
One of Bejo's wishes was to be able to generate a PDF of the available product information of a specific variety. Drupal's Entity Print module provides a good basis, but the DOMpdf integration was not sufficient given the HTML/CSS complexity that DOMpdf cannot handle. The WKHTMLtoPDF integration does work, but it doesn't run on the desired Alpine Docker images that we want to run on our Kubernetes environment, and the ongoing development on this was minimal. We found an option that met this better via Gotenberg,an opensource PDF generation platform via API’s, see : https://gotenberg.dev
This REST API based solution can be run as a standalone service, and is available as a docker image. It uses Chromium to do conversions, keeping us very close to what HTML and CSS can do in a browser. We have developed an integration for this with the Entity Print module to allow guttersberg to also be used as a service to generate a PDF document. We will also be making this available on Drupal.org soon.
See the placeholder at : https://www.drupal.org/project/entity_print_gotenberg

✔ Perfion integration 
With the old platform, we ran into limitations of how we stored data from Perfion in fields. Because we were using normal fields from Drupal itself we had to transform the data from Perfion so it could be stored correctly. Because of this we had to throw away the old field and create a whole new one in the content model if we wanted to do something different with the data, with a new piece of logic to transform the data.
Our solution meant that every field in Perfion had to have its own field in Drupal to be able to show a field label. Then the field label had to be imported from Perfion as a translation also to make sure this was also synchronized. 

With the new platform we have changed this completely: we don't transform the data. We store it as pure JSON in Drupal so the original data of the entire field from Perfion always exists in the website. As a result, we only need to create different 'formatters' for this field that ensure the field is visually transformed into that which is desired. The link therefore always remains intact and if we want to do something else with it, it is purely a frontend adjustment in Drupal. Furthermore, we can now put fields that are formatted the same in the same multi-valued field, also because Perfion adds a 'weight' to the data. This allows us to sort the data without having a huge set of fields. This has simplified the content model enormously and we are much more flexible when it comes to making adjustments to the presentation for these pages. 

As icing on the cake, we have now also taken into account the source language set-up and the possibility of translated data. As a result, Perfion can now provide translated content in alternative languages for a single domain. But also the management of the mapping between a field in the content model and a field in Perfion is fully managed by Bejo itself. As a result they have fewer maintenance costs when their content model changes in Perfion.