AI cuts onboarding time in half for new hires in the enterprise

This post was originally published in Engineering Enablement, DX’s newsletter dedicated to sharing research and perspectives on developer productivity. Subscribe to be notified when we publish new issues.

Onboarding is an expensive and time-sensitive phase of the developer journey, both for new hires and developers switching projects. For large enterprises, it can take months before new hires are fully productive, creating both financial costs and delivery risks. With AI tools now widely available, we were interested in understanding their impact on this critical phase.

To investigate, I analyzed data from six multinational enterprises and measured how quickly new hires reached their 10th pull request (PR)—an established metric for tracking ramp-up time.

The results were striking: engineers using AI daily hit their 10th PR in just 49 days—nearly half the 91 days it took their peers without AI. Even those using AI less frequently (weekly or monthly as opposed to daily) ramped faster, hitting their 10th PR in 73.5 and 84 days, respectively.

Half of new hires who don’t use AI tools still haven’t reached 10 PRs after 3 months of work. This same measure is less than 20% for new hires with daily AI usage. The trends suggest that AI tools are not just nice-to-have features but genuine accelerators of productivity, both during onboarding and beyond.

These productivity gains continue past the initial onboarding phase. Daily AI users continue to ship changes twice as fast as non-AI users: 1.3 times per week compared to just 0.65. This reflects what Microsoft has observed: the speed at which developers ramp up sets the trajectory for long-term success. As Microsoft researcher Brian Houck put it, “By a developer’s 10th PR, I have a greater than 50% chance of predicting what their code output patterns will look like 2 years in the future.”

These trends are consistent with other research we’ve done around AI and onboarding. In a separate study of more than 20,000 developers, we observed that while tenured engineers generally merge code more frequently than new hires, AI use shifts this dynamic. New hires who used AI daily outpaced their more experienced counterparts with less frequent AI usage by as much as 55%.

For engineering leaders, the takeaway is simple: AI helps new hires understand codebases, internal processes, and best practices faster than traditional onboarding alone.

It’s not just about writing code. AI helps new hires learn to work effectively in their environment from day one.