D3 Off-Label

Auto-writing Software

Good software writes itself. We all know the patterns and following them makes things easy. Not because we have memorized any monumental volume on design patterns, but because years of experience taught us what should be done on an almost intuitive level.

Also in a negative sense. We avoid duplication, globals, encapsulation violations. We know that planting a global variable somewhere to “facilitate” object interaction as innocent as it appears at the moment, throws a huge wrench into extensibility and new feature development. (This is known by a majestic name: legacy). Even if in a moment of weakness we allowed ourselves to relax unnecessarily the software itself would soon make us realize the error of our ways by resisting any attempt to extend it. And then with a sigh we go back regretting a momentary weakness and do things right.

In this case, however, software design dictated the user experience.

The Context

Last year, I did a brief stint on the DNA Storage Project at Microsoft Research. My task was to create an app that would streamline the process of encoding, synthesizing then decoding and analyzing the data on DNA molecules.

The UX Failure

Our intrepid UX designers sketched a pretty simple UX. The workflow appeared uncomplicated enough with just a few interacting entities. It was natural to split it into the “synthesis” and “analysis” parts, and then a few hierarchical grids or grids with links should have done the job. The MEAN stack fit the need and Azure was to host all the storage and backend processing.

Everything worked great until it came to the UX. No matter how much I huffed and puffed it would not yield. Whatever I did, I could not build the MVVM workflow. The model on the “synthesis” and the “analysis” side consisted of pretty much the same entities (files, pools, runs), however, their semantics while similar in some aspects were drastically different in others. While it seemed natural to have a model with a few abstract base classes wrapping the commonalities, the View-Model became an insurmountable obstacle: different View interactions demanded a lot of “similar but different” code in the VM; duplication was everywhere. The code was coming out entwined, and unmaintainable.


The inspiration came from the House episode Failure to Communicate. House is in Baltimore justifying some of his cases to a Medicare review officer. One of the cases involved prescribing Viagra to a woman with heart problems because she did not tolerate Nitroglycerin. Medicare was refusing to cover the off-label use.

Using D3 for UX development is an off-label use of D3. Perhaps I could have picked a different framework, but this was the one I was familiar with. The idea was to throw away MVVM and turn the entire experience in a data-driven “video-game” as one of the UX designers on the project called it. Then all the conceptual difficulties simply dissolved. With D3, I could easily streamline the peculiarities of the workflow, and, while new challenges emerged (entities interactions, drag & drop, etc), the software resumed its course “writing itself”.

Here is what this proof-of-concept prototype looked like.

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