

Ask HN: How can I estimate hosting costs for an app? - JakeWesorick

I have a Ruby on Rails app hosted on Heroku. The project is fairly far along, to the point where we are in talks with investors. We have all our numbers down except when it comes to hosting costs. How can I estimate what my hosting costs will be as my user base grows?
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dschwartz88
This is an awful oversimplification, but in my experience, there are two
different kinds of applications:

\- User-centeric (think: an e-commerce site): your costs are going to grow
somewhat linearly with your userbase/traffic. Do a load test to figure out how
many concurrent users each dyno supports and then model your costs with that
in mind.

\- Data-centric (think: an analytics platform): your costs are to going to
grow linearly with the amount of data points each customer is going to be
using. Figure out how many data points a single worker dyno (running 24x7) can
process and then model your costs with that in mind.

~~~
fataliss
You can also have a combination of both. But basically I second this post, you
have to figure out what is going to increase as your product gain momentum. If
you will be handling millions of requests because each client is going to do
plenty of them, are they going to store data... Like if you were Netflix, you
would have to consider the number of users growing, but also the size of your
catalogue. Try to define what direction your business is going as it grows and
then you will be able to narrow down the costs more accurately.

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shawnreilly
You need to determine the cost per User. Different Users might represent
different Usage Patterns, so I'd be looking for averages. If the Product is
already in production and you have an existing user-base, this is how I'd do
it; Correlate your user-base statistics (number of Users) in relation to your
hosting costs at different milestones and/or points in time. This metric will
give you some insight into how much it costs per User at different stages of
growth. This could include the growth of the user-base as well as the growth
of your Product (in terms of features and/or infrastructure changes). You
would want to identify any trends and/or variations with the resulting
averages over time. This will give you some data to work with in terms of
making projections.

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JakeWesorick
Possible side question: What does hosting your app cost right now?

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webnrrd2k
Just a thought: Would it be worth it to run a test site and simulate some
traffic? I think that would give you the best numbers for your app.

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rizz0
It also depends on how much you'll able to cache.

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deedubaya
I'm going on a road trip. I'll be driving on the interstate, and have already
gone half way.

How much gas will I use?

~~~
JakeWesorick
The same amount that it took to get you where you are right now? I also am
sensing you are trying to make a joke. While I may be very ignorant in this
area I'm not looking to made fun of, just for someone to educate me on what is
wrong with the question.

