All the following comments concern BCG client-facing consultants (which is the core business of BCG, though a minority of the employees are in these roles).
BCG is a demanding work environment. There is an expectation that things get done in the next hour or by the end of the day. Sometimes the timelines are "tomorrow" or "end of week". You always feel like you are in an environment where everyone is in it together, working in small teams of 3-8 people typically, so there is mutual accountability for getting work done quickly and to a high standard, however it does require 100% focus on efficiency and, to use a BCG term, "speed to output". Time to reflect, consider options, and plan? Typically you have 15-30 minutes to do all those steps (rarely hours, and never days or longer), then you need to execute, deliver, and iterate. Most people struggle to operate in that environment. Because of BCG's high-touch approach you need to expect to spend many hours every day in meetings, from 8am-6pm, meaning the time to "get work done" often over-flows into the evenings and nights. Most people, most of the time, manage to protect weekends and one Monday to Thursday night each week as "work free", but otherwise the work intensity is usually the main thing people struggle with. There can also be a high degree of travel. "Typical" in the US in 2025 is 3 days a week for 2 weeks of a month traveling to a client site, though many teams may be 4 days a week for 3 weeks of the month, and even in some cases every week. Certainly in some geographies and for some clients much of the work can be done remotely, which means a combination of "from home" and "from your local BCG office".