In Bedrock Edition, iron farms rely on villagers panicking near a zombie to spawn golems. This guide builds a compact 8-villager farm.
First, gather at least 8 villagers and bring them into a 16x16 platform. You will need beds for each villager plus a couple of extras.
Create a middle chamber that holds a zombie. Villagers need to see the zombie to get scared — use water streams to move them into view.
Build your kill chamber below with a lava blade or campfire so iron golems burn and drop loot into hoppers.
Keep the golem spawn area 10 blocks above the villagers to prevent golems from escaping their chamber.
Route all hoppers to a central chest. A well-tuned Bedrock iron farm produces roughly 80-100 ingots per hour.