Pros
The main plus is that the company is building something meaningful to help society rather than some BS consumer product or service, so this tends to unite colleagues from all functions and fosters a culture of positivity. Coupled with this, colleagues are extremely high-performing, experienced and knowledgeable. They share a common characteristic of being highly responsible so that problems get completely owned and are not left for others to deal with. There is excellent creative freedom, with management essentially pointing in the desired direction and leaving the specific technical solutions up to individual designers. One never feels hindered by beauracratic processes or long decision chains and can quickly get designs ordered, and as of recently there are even dedicated project purchasers available to help with this. There is good integration with the production department too, with both being in the same building, so that feedback flows quickly in both directions allowing designs to be quickly improved. Being able to work remotely is a plus during phases of work requiring focus
Cons
The tempo is high, with tight deadlines imposed by the pressure of scaling up, so if you like to have 2x 30 minute "fika" pauses every day you would feel more comfortable at a more established industrial company. The company is still growing so some aspects such as labs, workshops, etc. are not fully developed and have traditionally been left to the engineers themselves to build and equip.