It was a mixture of factors.
Data was to be dumped into a S3 bucket (minio), this created an event and anouther team had built an orchestrator which would do a couple of things but eventually supply an endpoint a reference to a plain/txt file for analysis.
For the Java devs they had to [modify the example camel docs.](https://camel.apache.org/manual/rest-dsl.html)
and use the built in jackson library to convert the incoming object to a class. This used the default AWS S3 api to create a stream handle which fed into the OpenNLP docs. .
The Python project first hit a wall in setting up Flask. They followed the instructions and it didn't work from setup tools. The Java team had just created a new maven project from the Intelij but the same approach didn't work for the Python team using pycharm. It lost them a couple days, I helped them overcome it.
Then they hit a wall with Boto3, the team expected to stream data but Boto3 only supports downloading, there was also a complexity issue the AWS SDK in Java waa about 20 lines to setup and a single line to call, it was about 50 lines in Python. On the positive side I got to explain what all the config meant in S3.
This caused the team anouther few days of delay because the team knew I used a 350MiB Samsung TV guide to test the robustness and had to go learn about Docker volume mounting and they thought they needed a stateful kubernetes service and I had to explain why that was wrong.
Basically Python threw up a lot of additional complexity and the docs weren't as helpful as they could have been.
QT is a cross platform UI development framework, its goal is to look native to the platform it operates on. This video by a linux maintainer from 2014 explains its benefits over GTK, its a fun video and I don't think the issues have really changed.
Most GTK advocates will argue QT is developed by Trolltech and isn't GPL licensed so could go closed source! This argument seems to ignore open source projects use the Open Source releases of QT and if Trolltech did close source then the last open source would be maintained (much like GTK).
Personally I would avoid Flutter on the grounds its a Google owned library and Google have the attention span of a toddler.
Not helping that assessment is Google let go of the Fuschia team (which Flutter was being developed for) and seems to have let go a lot of Flutter developers.
Personally I hate web frontends as local applications. They integrate poorly on the desktop and often the JS engine has weird memory leaks