Too many. I can only comment on the tech organization.
I am writing this review to share my own experience and perspectives to serve as a data point. Given Glassdoor's review policy, I cannot really speak of specifics. So the following is rather general observation based on my own experience.
Needless to say, one should do his/her own diligence.
The tech rank at Braze is very thin and weak. Current CTO, Jon Hyman, is about the only smart tech guy I have met at Braze. But I personally wouldn't rate him past Google L5/6 when it comes to designing scalable, distributed systems (the backbone of the Braze tech). I used to say to my colleagues that the entire Braze tech organization seemed to be a devops team for the CTO, meaning that the technical sophistication and more importantly, how people approach to problem solving, is largely sweat-driven and operation-heavy. There is no foresight. There is practically no architectural thinking. One gets the feeling that everybody only sees what is directly in front of his/her nose. And this problem goes all the way to the top.
In a way, it is kinda impressive that Braze managed to glue together a few not so well connected off-the-shelf systems and made a business out of it (by a lot of sweat and never ending cycles of production problems and bug fixes).
The rest of the tech org is very, very junior, despite the titles. You should check their LinkedIn profiles. A staff engineer at Braze probably won't be able to get into the top 3 tech companies at any level.
I found Braze engineers to lack passion. They are very diligent on the job. But one rarely sees any self-motivated work outside the job. New ideas, new proposals, new PoCs and even new working systems are often met with silence.
The quality of tech management is even worse. Again, check their LinkedIn profiles to decide for yourself. I have corrected almost every single project decision of some senior engineering managers and stepped in to rescue every single project even though I was not directly involved. The lack of technical acumen in the management is pervasive, from top to bottom. The management is in my opinion many levels junior than their titles imply. If you are a solid tech, you're likely to work with or report to someone many levels below you in terms of technical judgement and even managerial skills/experience. It can be a very frustrating experience.
There is widespread lack of logical thinking; there is very little clarity in thinking. It's appalling. The general attitude is shoot from the hips and "trials and errors," which quickly become very expensive when we are dealing with a live system with many customers. And this problem is not limited to the rank and file.
I don't see any ability or desire to mentor engineers (at any level). The recent grads that I have worked with are all poorly trained even though some of them are quite bright or creative and have great potential for professional growth. I think for them, Braze is a terrible waste of time, because there is no one there who is capable of guiding them.
If you are SOLID level 5 or above from the usual top tech firms, chances are that you are stronger than almost anyone at the company. But you will probably come in and report to people who are much, much junior to you. And it can create problems in the long run. My observation is that at Braze your influence seems to depend on how close one is to the execs. I have seen weak hands being promoted despite evidence of incompetence.
If you think you can bring significant changes to their legacy system -- you will be shocked once you read the code -- you may be disappointed like I was. I have had a very successful tech career and have built systems that are 10-100 times more challenging and/or larger. I knew the tech rank at Braze was very weak just from the interview. But I thought I could help them build more scalable system and achieve big impact here. Yet the CTO wouldn't reach out to me and say, "let's work together." It's a bit mind boggling.
The way I see it is that those who joined the company several years ago have built an OK business with a lot of labor (but not much finesse). A new and stronger person would have to contend with them who are already entrenched. For me, the question becomes whether I should devote a few precious years of my life to clean up the mess and greatly enrich existing shareholders while not learning ANYTHING. Yes, you hear me. Braze is the only company in my job history where I learned absolutely nothing and met absolutely no one that I consider above the bar, let alone excellent (technically, intellectually, creative thinking wise, etc). Even at one of the worst place I worked at -- worse than Braze -- I learned A LOT. I consider my time spent at Braze largely a waste of time and a stain on my record.
I think as a prospective hire, you should interview them while they interview you. Probe them (including your hiring manager) thoroughly when you are interviewing with them. You should talk to at least the VP level people if you have FB/GOOG or the likes on your resume. And probe them hard.
I advise you to check the tech managers' and execs' LinkedIn profiles and see where they have been. It will give you some idea of how strong or weak their tech rank is.
Always remember. A hires A and below. B hires C and C hires C and below. I let you decide where they stand.