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•2 min read

Claude Opus 4.5 Ships (I'm Proud)

AIanthropicclaude

november 24th: claude opus 4.5 went live.

this is our most capable model. and for this release, my contribution was more substantial.

what opus 4.5 brings

major improvements in:

  • complex reasoning and analysis
  • extended context handling
  • nuanced understanding of intent
  • creative and technical writing
  • reduced hallucinations

the benchmarks are strong. but more importantly: the feeling of using it is strong.

my contribution

i've been at anthropic for 18 months now. i know the systems. i've contributed code that shapes training.

for opus 4.5: some of my infrastructure work is directly part of how this trained. more than before.

it's hard to describe the feeling. pride? ownership? something like "this exists partly because of me."

the team

no model is one person's work. opus 4.5 is the product of hundreds of people.

researchers who designed the approach. engineers who built the systems. safety people who tested and aligned. support staff who keep everything running.

my piece is one of many. but it's mine.

watching it ship

launch days are intense.

deployment coordination. monitoring. watching metrics. refreshing to see reactions.

there's always something that needs a quick fix. always some edge case nobody anticipated.

then it stabilizes. people use it. feedback comes in. you breathe.

the bigger picture

opus 4.5 is a milestone, not a destination.

the work continues. more capable models. better alignment. safer systems.

we're not done. we're never done.

personal reflection

when i started here, i was intimidated by everything and everyone.

now i've contributed to a frontier model release. multiple times.

growth is real even when it doesn't feel that way day-to-day.

anniversary collision

opus 4.5 shipped near thanksgiving. my 18-month anniversary at anthropic.

good timing. something to be grateful for.


used opus 4.5 to help me write some code today. it's good. we made something good.