Stack frames and failure signatures

Each method invocation pushes a frame (locals + operand stack + return address). Two consequences you can test:

Depth is finite. Unbounded recursion throws StackOverflowError — and it is just an Error you can catch (though you almost never should):

static int forever(int n) { return forever(n + 1); }
try { forever(0); }
catch (StackOverflowError e) { /* depth limit reached */ }

Frames unwind exactly. When an exception crosses frames, each frame's finally/catch runs inside-to-outside. Combined with the stack-only operand model, this is why the JVM can produce a precise stack trace at any moment.

Deep recursion in production code is a design smell — prefer iteration or explicit stacks — but a professional must recognize the signature of each failure: SOE = depth, OOM = live set, Metaspace OOM = class churn.