SAAS and clouds are essentially leases. Let’s look at the area of applicability here.
Rent is good for temporary use:
- I need something for a week
- you need something once a month
If you rent permanently, it is not economically profitable.
Maybe it’s different in the clouds? Unfortunately, no. Let’s start by considering the cost of computing resources. The ratio is about this:
- 1x for renting an iron server in Hetzner
- 2x for VM in DigitalOcean
- 4x for VM in the cloud
The plus-minus ratio has been maintained for many years.
Does the additional cost in the cloud give you something? In fact, no:
- dynamism? it already exists at the level of regular VMs
- reliability? not at all: from experience, cloud VMs are much less stable than regular VMs, and even more so hardware. So all software should be built in such a way that a particular VM can break at any time.
- any additional services? No, it’s just a VM. Additional specialized tools are worth the extra money of already expensive cloud VMs
If you want to somehow reduce costs, then you need to enter into long-term lease agreements with cloud providers.
Separately, it can be said that during a period of high demand (for example, one of the large data centers has some problems and it does not matter what kind of data center it is) it may turn out that there are simply no free resources. Therefore, it is better not to create critical things dynamically.
The Vendor-lock problem is also quite obvious: the clouds are constantly trying to release some kind of vendor-specific solution. In practice, moving from one cloud to another is quite difficult. Because of this, many companies use Kubernetes as a universal solution deployment mechanism (but even in this case there will be some amount of dependency, because, for example, monitoring is often specific to the cloud).
At the same time, if the infrastructure costs are small (for example, less than salary of one administrator), then the use of clouds is more than effective, since the level of services will still be very high, and the costs are lower than for organizing their own analogues.