As for any product, measuring how much value your platform brings to the organization is important. Products are only worth investing in them when they provide value to their users.
Sometimes, it might be a bit difficult to measure the impact of an internal platform. It doesn’t bring any money (in most cases), at least not directly. You need to get a bit creative in what to measure instead.
2 metrics
Platforms reduce cognitive load of product focused teams and free up time to focus on the product specific tasks. Platforms save time that can be used in building more revenue bringing features. So one metric to track could be how much time the platform saves for the developers, time they use on building features.
But I would not stop there. I would also track the general satisfaction scores of the platform users for the services it provides. You can save time and provide a crappy service. That is still good, but it also shows space for improvement. Platforms that save a lot of time and do it with an excellent service are the ones leaders have no choice but to invest in and grow.
The data required for these is something I see as important to gather anyway before launching the platform widely.
Choose the metrics you are being measured on
These are just 2 basic examples of metrics to track, but the metrics could be close connected to the mission and vision of the platform and its team. These metrics are also important for the company leaders when deciding on budgets for the platform teams. Since they don’t bring any money, then a proxy metric should be used. I assume the platform team knows better than any executive what are the best proxy metrics for their team and platform and I believe it is in their best interest to define and track those.
Not bringing direct income makes sometimes the platform teams not be seen so important or valued. But no serious scale-up can grow without heavily investing in the right platforms and their teams.