In general, a shul whos purpose is mainly to churn out many minyanim with several room.
The type of place where you just KNOW there will be a minyan, versus your local shul that probably has 1 7:00 shacris. Or maybe has even 3 shacrisim and only 1 room.
Not all are equal to be clear.
The classic original infamous ‘shomer shabbos’ in Boro Park has Shacris Mincha Maariv all overlapping with each other thoughout the day.
Then you have Landau’s where you wont have overlapping, but odds are if you show up at a normal time for that Tefillah, you’ll have a minyan starting within the next few minutes.
Then you might have the ‘Minyan Factory Juniors’ that churn out Shacrisim, but only have a few Mincha Maarivs.