Pros
As a workplace experience, it can be a lot of fun, and offers a ton of raw material for personal growth. It's certainly tough, but for mid-level individuals looking to cut their teeth, broaden their horizons, and to some extent "choose their own adventure", it's actually pretty great. There is a good deal of autonomy and the potential to directly make a difference on many levels without excessive red-tape. If you're looking to develop as a leader you're surrounded by opportunities to step up - there is plenty of demand for ownership, and nothing to stop you diving right in. And typically you won't be rigidly boxed in whatever you do - you can explore your interests, learn new skills on the side, and even make lateral career moves relatively easily. Ad-tech by nature presents a variety of pretty singular technical challenges, as do 10+ yr old companies, so there’s plenty to get your teeth into. So if you’re game to forge your own path - let’s go, there's a lot to explore.
Cons
There can be a slightly chaotic energy to things, and the same aspects that can be exciting can also be exhausting. Continually self-driving doesn't lend itself well to work/life balance, and you’re on your own to draw those lines - leadership do make nice gestures, but there’s not much enablement day-to-day. Realistically there isn't the headcount (or time) for cross-training - most people are wearing a few hats to plug coverage gaps anyway - so the better you become at your job, the more certain you are to be a bottleneck. It can be a little demoralizing at times. For entry level hires, things can be hit-and-miss - you might happen to end up with a fantastically gifted mentor, or on a flagship project with strong team support… or you might just as easily be left to fend for yourself in a swamp of tech debt. Someone smart and willing is rarely far away... but you're going to have to find them. So being self directing is a must, in learning as well as managing your own work - be willing to seek people out and drive the conversation. There is very little hand holding, and not much by the way of formal support structures in place at that level.