I'm not that surprised, though 3-4 months does feel like a long time.
When I was at early Twilio (2011? 2012? ish), we would completely tear down our dev and staging environments every month (quarter? can't remember), and build them back up from scratch. That was everything, including databases (which would get restored from backup during the re-bring-up) and even the deployment infrastructure itself.
At that point we were still pretty small and didn't have a ton of services. Just bringing my product (Twilio Client) back up, plus some of the underlying voice services, took about 24 hours (spread across a few days). And the bits I handled were a) a small part of the whole, and b) some of the easier parts to bring up.
We stopped doing those teardowns sometime later in 2012, or perhaps 2013, because they started taking way too much time away from doing Actual Work. People can't get things done when the staging environment is down for more than a week. Over the following 10 years or so, Twilio's backend exploded in complexity, number of services, and the dependencies between those services.
I left Twilio in early 2022, and I wouldn't have been surprised if it would have taken several months to bring up Twilio (prod) from scratch at that point, though in their case it would be a situation where some products and features would be available earlier than others, so it's not really the same as an e-commerce site. And that was when I left; I'm sure complexity has increased further in the past 3 years.
Also consider that institutional knowledge matters too. I would guess that for all the services running at Twilio, the people who first brought up many (most?) of them are long gone. So I wouldn't be surprised if the people at M&S right now just have no idea how to bring up an e-commerce site like theirs from scratch, and have to learn as they go.
When I was at early Twilio (2011? 2012? ish), we would completely tear down our dev and staging environments every month (quarter? can't remember), and build them back up from scratch. That was everything, including databases (which would get restored from backup during the re-bring-up) and even the deployment infrastructure itself.
At that point we were still pretty small and didn't have a ton of services. Just bringing my product (Twilio Client) back up, plus some of the underlying voice services, took about 24 hours (spread across a few days). And the bits I handled were a) a small part of the whole, and b) some of the easier parts to bring up.
We stopped doing those teardowns sometime later in 2012, or perhaps 2013, because they started taking way too much time away from doing Actual Work. People can't get things done when the staging environment is down for more than a week. Over the following 10 years or so, Twilio's backend exploded in complexity, number of services, and the dependencies between those services.
I left Twilio in early 2022, and I wouldn't have been surprised if it would have taken several months to bring up Twilio (prod) from scratch at that point, though in their case it would be a situation where some products and features would be available earlier than others, so it's not really the same as an e-commerce site. And that was when I left; I'm sure complexity has increased further in the past 3 years.
Also consider that institutional knowledge matters too. I would guess that for all the services running at Twilio, the people who first brought up many (most?) of them are long gone. So I wouldn't be surprised if the people at M&S right now just have no idea how to bring up an e-commerce site like theirs from scratch, and have to learn as they go.