Abstract: Methods and systems provide for a notebook interactive programming environment, having out-of-order code-cell execution, which communicates potential cell execution outcomes. If an event handler receives an event (e.g., open notebook, code change, code execution, etc.) for a cell, without a request for a specific type of analysis (e.g., data-leakage, stale-state), intra-cell analysis is executed based-on the cell's abstract semantics, and an abstract state and pre-summaries are output that indicate the cell's propagation dependency (unbounded variables). If an analysis is associated with the event, starting with the stored abstract state, inter-cell analysis is recursively executed on successor cells having propagation dependencies, until a terminating criteria is reached. Outcomes (e.g., affected cell, line number, bug type, metrics, etc.) are sent via the notebook user-interface to warn users, ahead of concrete code execution, of hypothetical unsafe or safe actions in executing the notebook's code cells.