istSOS is a complete and easy to use sensor data management system for acquiring, storing and dispatching time-series observations. istSOS is compliant with the Sensor Observation Service standard (SOS) version 1.0 and 2.0 from the Open Geospatial Consortium (OGC) and offers unique extended capabilities to support scientific data analyses (integrated quality assurance, RESTful API, on the fly processing with virtual procedures, remote data aggregation, time-space re-projection etc.). istSOS core libraries are written in Python while it easy to use interface is Web based. This presentation will illustrates the projects and its latest enhancements, including: The OGC SOS 2.0 standard implementation Authentication and Authorization System Alert and Notification system Finally the presentation will discuss the challenges that istSOS need to face for entering in Big Data showing results of scalability tests and ongoing new IoT driven development features. The robustness of the implemented solution has been validated in a real-case application: the Verbano Lake Early Warning System. In this application, near real-time data have to be exchanged by inter-regional partners and used in a hydrological model for lake level forecasting and flooding hazard assessment. This system is linked with a dedicated geoportal used by the civil protection for the management, alert and protection of the population and the assets of the Locarno area.