Pros
Cognex is good employer, at least for software engineers. You are expected to be smart and competent. You are not micromanaged. Code reviews are strict but fair. It varies by manager but most are extremely accommodating of family issues or in general needing to leave the office without much notice or explanation. You are trusted to get your work done and as long as you do, no one is looking at your hours or giving you a hard time. People stay at Cognex for a very long time and for good reason. Pay is good and the company is extremely stable internally.
Cons
Demands are high and sometimes unpaid overtime is necessary to keep things moving. I think technically you could demand to be paid for this time, but more likely than not, your manager would just tell you to go home and push the deadline. You are for all intents and purposes a salary employee. It would be nice if the company acknowledged that. Regardless, pay is fair for a 40 hour week, and you're not punching a clock, so it doesn't matter too much. The development environment and tools are ancient and build processes are arcane to the point of being a running joke. Fellow employees are supportive. No time is given for experimental ideas. The company is vaguely understaffed and all time goes towards concrete product development.