Day 3 of my AI challenge was productive. I re-worked the name matching logic of my revsport bookmarklet to be a lot more robust. I also updated the docs, putting installation instructions right up the top, and recorded a nice video of it in action.

The code is at https://github.com/lukesleeman/revsport-crew-entry-bookmarklet

Tools I used

• Claude Code, then Cline
• I switched between a few models, trying out the very pricy Claude Opus 4.1 model
• Apart from the JS used in the bookmarklet, I also generated some python script to modify test data.

What went well

• Matching names is non trivial. I spent some time getting together test data based off previous regattas, then asked the agent to come up with an approach. It developed a robust multi-strategy approach, that I would have taken a long time to come up with.
• We were able to quickly iterate through various UI design ideas for dealing with the name matching process, coming up with a good final design
• We were able to remove personally identifying information from a copy of the revsport webpage, allowing me to use it for a video recording, and to check the page in.

What went badly

• WOW the Opus 4.1 model is expensive to use 💸
• I asked the tool to replace personally identifying information in a saved copy of the revsport webpage, with mock data. It tried to do this using sed, and landed up in all kinds of trouble. Prompting it to create a script to modify the page worked much better.

What I learnt

• For data processing tasks its often better to get it to write a script to do the processing, rather than having the model attempt it directly.
• I’m not sure the Opus 4.1 model actually gives better results. Its smarter - but that sometimes leads it towards choosing solutions that are too smart for their own good! In coding, a simpler approach of breaking things down into basic steps often gives better results.
• This feels a lot like helping guide a junior dev. Being able to provide good reviews of the code, and guide the tool in better directions are critical skills.

Originally posted on Mastodon