The big cons fall into two categories: engineering and company.
Engineering specific:
1. The internal tools, compared to open source projects and other companies, suffer from immense proliferation and domain overlap. There are too many ways to deploy code, too many ways to look at a metric graph, too many ways to build a Java library, too many ways to spin up an RPC server, and the list goes on. This ultimately means that none of the products are very satisfactory. There's too much license to "innovate" on the fundamental building blocks, and the engineering culture as a whole needs to enforce more standards.
2. It's an extremely common practice for engineers (i.e. with a title of software engineer) to have direct reports. The result is a bunch of very technical leaders who don't care as much about people operations. This is great when you need backing for a proposal, but sub-par when you need to talk about career development or other non-technical topics.
3. Technical Googlers are promoted predominately for "impact" - think launching a new service, or saving the company $Xm. There does not seem to be heavy motivation to promote engineers who work hard to maintain stable and important systems. It's a running joke that in order to get promoted, it's better to deprecate something reliable and create something new. In other words, Google is an excellent place to gain experience, but to get "promoted", you're probably better off seeking out new opportunities.
4. While mostly good people (especially at a company of 80k), Googlers can sometimes come across as entitled. Yes, finances in the Bay Area is hard even on a salary of $120k+, but the perspective on how much of a privilege it is to work here is sometimes lost.
5. Google is struggling with some of the same issues that the US is politically. The company has the best intentions, but does fall into a hysteria over "diversity". Less than 50% hiring of females in engineering is seen as a systemic problem. Google is slowly starting to realize that this is mostly a pipeline problem, especially considering that the industry (and company) makes enormous efforts to hire existing qualified women. However, leadership does not seem very interested in respectful but contrary opinions on this topic, as the firing of James Damore demonstrated. If you care about racial and gender equality, but have doubts about a leftist political agenda, you may occasionally feel afraid to speak up at Google.
