When does @Transactional roll back — and what's your checklist for the classic ways it silently fails?

@Service
public class TransferService {

    @Transactional
    public void transfer(...) throws SettlementException {
        debit(...);
        try {
            credit(...);
        } catch (DataAccessException e) {     // ① caught -> interceptor never sees it
            log.warn("credit failed", e);     //    method returns normally -> COMMIT (debit only!)
        }
        settle(...);                          // ② throws CHECKED SettlementException
    }                                         //    -> default rule: still COMMITS

    @Transactional                            // ③ called via this.recalc() elsewhere
    void recalc() { … }                       //    in class -> proxy bypassed
                                              // ④ non-public -> not advised at all
}

// Fixes: rethrow or mark rollbackOnly; @Transactional(rollbackFor = SettlementException.class);
// move recalc() to its own bean; make advised methods public.