A CRO firm typically offers a mix of strategy, testing, design, and analytics. They’ll audit your site or funnel, identify drop-off points, and run A/B or multivariate tests to improve performance. Many firms also handle UX design, copywriting, and dev implementation for any changes they recommend. Some go further with behavioral research, customer surveys, or analytics setup. A good firm will partner with you over time, constantly testing, learning, and iterating to get better results.