Artificial intelligence is no longer just a support tool for developers; it’s becoming a central part of how code gets written and shipped. A new survey from Fastly highlights just how much senior developers are leaning on AI, with surprising results that show trust in AI tools is growing among the most experienced professionals.
Senior Developers Lead in AI Adoption
Fastly’s July 2025 survey of 791 professional developers found that 32% of senior developers, those with more than 10 years of experience, ship code where over half is AI-generated. By contrast, only 13% of junior developers reported the same.
This suggests that senior engineers not only use AI tools like GitHub Copilot, Gemini, or Claude more aggressively but also trust AI-generated code in production environments. Interestingly, this trend emerges despite ongoing concerns about “vibe coding,” where AI may introduce unseen vulnerabilities.
Balancing Speed with Quality
The survey also revealed that developers frequently edit AI-generated code. Nearly one in three respondents (28%) said they fix or refine AI output often enough to offset much of the time saved. However, only 14% reported rarely needing to make changes.
Yet, even with these extra steps, most developers agree that AI makes them faster. More than half said AI tools improved their workflow, with one senior developer noting:
AI can efficiently identify and fix errors in code, outperforming human workers in this task.
On the other hand, some junior developers pointed out the downsides, saying AI sometimes makes incorrect assumptions that require rework.
Senior vs. Junior Developer Experiences
Senior developers appear more confident in correcting AI’s mistakes, which may explain why they benefit more from speed gains. About 59% of senior developers said AI helped them ship code faster overall, compared to 49% of junior developers.
Interestingly, while more than half of juniors reported “moderate” improvements in speed, senior developers were twice as likely to see significant gains. The ability to spot and correct AI errors quickly seems to give them an edge.
Beyond Productivity: Enjoyment at Work
The benefits of AI go beyond just efficiency. Nearly 80% of all surveyed developers said AI tools made coding more enjoyable. Whether by skipping repetitive tasks or experiencing the satisfaction of instant code generation, developers across all levels are finding value in AI.
This shift could play a role in long-term developer satisfaction and retention, especially as AI tools become more integrated into daily workflows.
Key Takeaways from the Survey
- 32% of senior developers ship more than half their code from AI tools.
- AI improves productivity for both senior and junior developers, but seniors gain more speed overall.
- Editing is common: 28% fix AI code often, while only 14% rarely need changes.
- Enjoyment matters: Nearly 80% say AI makes coding more fun.
Final Thoughts
The Fastly survey underscores an important shift in the software development world: AI is no longer just an assistant but a trusted partner in writing and shipping code. Senior developers, with their experience and ability to manage AI’s limitations, are leading this transformation.
As AI coding tools continue to evolve, their role in shaping productivity, job satisfaction, and the future of software development will only grow stronger.
