There is a great option that is relevant to the "coder" audience. With the Elixir programming language (based on Erlang), a project called Nerves (https://nerves-project.org/) enables you to create IOT devices with features that include live device upgrades.

A supporting project called Nerves Hub (https://www.nerves-hub.org/) allows you to manage and securely deploy IOT firmware upgrades. It can be self-hosted/managed as well. It is all OpenSource. It is actively used by OpenSource FarmBot (https://farm.bot/) and others.

I'm on the ElixirMix podcast and we interviewed the creators here: https://devchat.tv/elixir-mix/emx-008-nerves-with-frank-hunleth-and-justin-schneck/

Justin spoke about NervesHub at ElixirConf 2018. https://www.youtube.com/watch?v=O9VhFJewv5w

I encourage you guys to invite him on to talk about it.

If people are interested in developing software for IOT devices and want to use OpenSource/free solutions, they should definitely investigate Nerves and Nerves Hub.