tl;dr - author cites a study from early 2025 which measured developer speed of “experienced open source developers” to be ~20% slower when supported by AI, while they’ve estimated to be ~20% faster.
Note: the study used sonnet-3.5 and sonnet-3.7; there weren’t any agents, deep research or similar tools available. I’d like to see this study done again with:
1. juniors ans mid-level engineers
2. opus-4.6 high and codex-5.2 xhigh
3. Tasks that require upfront research
4. Tasks that require stakeholder communication, which can be facilitated by AI
I’d be thrilled if that AI could finally make one of our most annoying stakeholders test the changes they were so eager to fast track, but hey, I might be surprised.
It can facilitate that, certainly. Idk about the background of that stakeholder, but AI can help drafting communication with the right tone to show the necessity. It can help to write a guide on how to properly test the specific feature. It can write e2e tests that the stakeholder could execute from their environment.
Of course, all of that can be done by humans, too. But this discussion is about average speed of a developer, and there’s a reason many companies employ product owners for the stakeholder communication.
Note: the study used sonnet-3.5 and sonnet-3.7; there weren’t any agents, deep research or similar tools available. I’d like to see this study done again with:
1. juniors ans mid-level engineers
2. opus-4.6 high and codex-5.2 xhigh
3. Tasks that require upfront research
4. Tasks that require stakeholder communication, which can be facilitated by AI