There was a problem that players didn't really want to be distracted by upgrading and writing code in the middle of a battle. Initially, I solved it by showing the upgrade window on level-up, forcing players to leave the flow state at random moments of the game and think about writing code. I find a lot more elegant solution: dividing the game into rounds, after each of which you can upgrade and edit the code.

This way, for 1.5 minutes nothing will distract you from the action (except for errors in your own code).

Upgrades

I haven't implemented all kinds of upgrades yet, but now I've clearly defined the development vector: no more division into hardware and software - all upgrades are now essentially hardware. Writing code is not bound to upgrades in any way.

You can create/update/delete any code as much as you want (but not during rounds, though I will think about it and look at the test results). The only limitation will be your hardware. For code storage we need a hard memory (improved by SSD upgrades), for code execution and storage of variables we need RAM (RAM upgrades), for running daemons we need additional cores.

Thus there is much more space for builds, as well as the need to balance between combat improvements and automation.