Datomic Ions video


The video from my Datomic Ions talk is now available on ClojureTV, and you can read the example code on Github.

Write some fns, have some fun, deploy to AWS!


Hi Stu,

Just wanted to jump in and say I love the talk! Thanks for it. If I had one comment, and I don’t know if it’s just me, but when I’m planning on kicking the tires (as I’ve been burned in the past on this) one thing I like to know is a sense of cost. I’ve been actively holding back on trying out datomic cloud and ions because I couldn’t work it out in a reasonable timeframe, sticking to on-prem which I’ve been pretty happy with.

I’m really glad that you addressed this in the talk. Especially that solo is a viable way or testing the app, running a realistic small instance with a minimal footprint. Perhaps it’s been covered in way I didn’t really pick up on, but I’m definitely more confident about going to boot up an ions instance in solo now to see how well it meets my needs. Hopefully if it works out and the load picks up, I’ll be happy to move to production.

Thank you.


Hi Folcon,

Glad that the talk helped. The pricing page page has some information and links out to the AWS calculators, and this forum thread has more information about production. Note that with ions you should also model the AWS Lambda and API Gateway costs (if you are using these optional features).

That said, it is easy and inexpensive to start a system (e.g. just for a few hours) and try a representative load for your actual domain. I strongly recommend that anyone building any cloud app do this. We would love to hear about your experience doing this.


FYI the Amazon Store Pricing Calculator is still broken for me. I now get 4 items in the Fulfilment category (2 Solo and 2 Production). And switching between them will produce erroneous results. For example selecting one of the Solo items will add a Large instance option while changing it to Production then removes that option. Is the code under Cognitecs control? i.e. Who’s writing this stuff? Is it Amazon?



Hi Tim,

The pricing calculator is under AWS control. We have reported this issue, please feel free to do so as well!

Also feel free to ask any specific pricing questions here in the forum and we will answer them.