If you're creating video testimonial content. Timing is key to creating a quality video.
When you create your video, make sure that you keep it relatively short. Anywhere between 60-90 seconds.
If you think your video is the perfect length you still may need to make it shorter. So how take however long it is and make it shorter. People have shorter attention spans these days, it's hard to get people to watch something for a long period of time.
Be aware of where it's going like if it's going on a social media feed, it may be best if you cut it into several shorter clips that you spread out over several days to keep people engaged with quickly digestible content.