CartPole with a Deep Q-Network

In my last post I developed a solution to OpenAI Gym's CartPole environment, based on a classical Q-Learning algorithm. The best score I achieved with it 120, although the score I uploaded to the leaderboard was 188. While this is certainly not a bad result, I wondered if I could do better using more advanced techniques. Besides that I also wanted to practice the concepts I had recently learned in the Machine Learning 2 course at university. By the way, to all the students among you: I found that one of the best way to learn about new algorithms etc. is to actually try to implement them in code!