As organizations grow, it's not unusual for things to slow down. They don't need to, and in the best organizations, they can accelerate. But if you are seeing a slowdown, these are the first things to look for.
Technical debt. Often, the architecture does not facilitate or enable the rapid evolution of the product. This is not something that can be fixed overnight, but it needs to be attacked in an ongoing and concerted effort.
Lack of strong product managers. The lack of a strong and capable product manager is typically a major reason for slow product. The impact of a weak product manager shows up in many ways, but it shows up very visibly as a team of mercenaries rather than missionaries. The product manager has not inspired or evangelized to the team, or the team has lost confidence in their product manager.
The lack of a strong and capable product manager is typically a major reason for slow product.
Lack of delivery management. The most important function of the delivery manager is to remove impediments, and the list of impediments grows non‐linearly as the technology organization grows. Most impediments won't go away quickly without someone actively chasing them down.
Infrequent release cycles. Most teams with slow velocity have release vehicles that are too infrequent. Your team should release no less frequently than every two weeks (very good teams release multiple times per day). Correcting this typically means getting serious about test automation and release automation so the team can move quickly and release with confidence.
Lack of product vision and strategy. It's essential that the team have a clear vision of the big picture and how their immediate work contributes to the whole.
Lack of co‐located, durable product teams. If teams are split across locations—or worse, if engineers are outsourced—besides the dramatic decrease in innovation, the velocity of the organization will suffer significantly. Even simple communication becomes difficult. It gets so bad that many outsourcing firms will add another layer of people to coordinate and communicate, which usually makes things worse.
Not including engineers early enough during product discovery. The engineers need to participate in product discovery from the start of ideation. They will often contribute alternative approaches that can be significantly faster to implement if you include them early enough in the process for the product manager and designer to adjust. If not, their critical input will come too late in the process.
Not utilizing product design in discovery and instead having them try to do their work at the same time the engineers are trying to build. Not doing this will both slow things down and lead to poor designs.
Changing priorities. Realize that rapidly shifting priorities cause significant churn and substantially reduces the total throughput and morale.
A consensus culture. Many organizations strive for consensus. While this typically comes from good intentions, what this means in practice is decisions are very hard to make and everything slows to a crawl.
There are, of course, any number of other causes of slow product, but in my experience, these are among the most common culprits.