Amazing!... or as Rocky would say, "Amaze! Amaze! Amaze!"
I was a huge fan of The Martian. I especially liked how Andy Weir "did the math" in that story to describe technical problems and their solutions. Even though I'm terrible at math and it was my worst subject in school, the author makes it so approachable and interesting. So when I learned that Andy Weir had written an interstellar, alien first-contact novel, I was concerned that he would focus on the dramatic and get less into the guts of individual problems and the details of their solutions. I am pleased to say that my concerns were unfounded.
The story is compelling from start to finish and, although it includes the techie stuff that I like, character development was superb, the drama was intense, and the emotional aspects of the story were compelling.
Overall, Project Hail Mary is the best book that I have read this year, and possibly ever!