A firm as large as GS a lot of the culture type of questions come down to the team you’re in. Teams in goldman are usually pretty small so things like WLB vary team to team quite a lot.
Software Engineering roles in GS are spread across divisions - there are roles which involve working on software and infra which is used by the entire firm - the engineering standards here, especially in the smaller teams are pretty high, a lot can go wrong when your software operates at a user scale of the order of tens of thousands. Larger teams here have good WLB as support, on call etc is distributed fairly, projects are scoped and managed properly by MDs or PMs in some cases. Smaller groups for some critical infra are on the hook for support calls during awkward hours but then they make sure you’re compensated for it monetarily come year end bonuses.
There are roles within business units where the scope is limited to progress the technology and automation needs for your group only - think portfolio management tools, electronic trading, etc. Here the pace of work is usually quicker and the first aim is to get to market faster - a lot is driven by client demands and iteration is better than perfection in this space. The work is usually of two sorts - one is maintenance of systems (aka run the bank) and the other is build new systems to address a gap or improve on something existing (aka build the bank) - think latency improvements, reducing infra costs, improving client execution, better scaling etc etc. You’d want to be on the latter as a software engineer and usually a product takes around a year or two to go from initiation to be first production instance and another year or two to be rolled out fully. Sometimes there are supporting teams to drive the second part of things.
In this part of the business WLB comes down to the state of the project you’re on and what the deadlines / demands are.