When I worked there, I was indeed hired as contractor which was not the best situation. I recently learned that the company improved worker relations and benefits by onboarding as employees, all contractors. But personally, being a contractor did not bother me because it was made clear from the start. This job was not about earning a lot of money. It was about making compromises to see a project succeed, taking direct and innovative measures to tackle climate change and making the transition to sustainability easier and more transparent for customers.
It is a small company so you might not be doing exactly what you want right away. You most likely will be wearing many hats and be needing to adapt to how the market evolves. This means you might be working on non-technical tasks as well, such as marketing or scoping other opportunities for the company. (But it gets you exposed first hand to the different challenges small companies face). This industry is not the most stable one and not one that is easy to succeed in, which is why a lot of people come and go. It can feels tough sometimes but it helps to keep the big picture in mind and that there are necessary steps and detours to take before you get there.