The Joint Expert Speciation System (JESS) is presently the world’s largest single source of thermodynamic information about aqueous electrolyte solutions. Comprehensive and up-to-date thermodynamic models undoubtedly require such large databases but size alone, without well-designed data structures and good data assessment procedures, is insufficient. Computer databases are not like tables in a book; they should be constantly evolving, easy to search and specifically designed for processing by large-scale, automated facilities, including tests for careless errors and internal consistency. The maxim ‘garbage in, garbage out’ is today even more relevant than ever: without expert analysis and critical judgement, limitless storage capacity and computational power are likely just to add confusion rather than achieve meaningful insights into chemical problems. Several examples are provided to demonstrate the application of new methodologies to problems of differing size and complexity including harmonization of aqueous reaction equilibrium constants for more than 50,000 chemical species, systematic critical assessment of the thermophysical properties of aqueous glycine and its solid–liquid equilibria over wide ranges of temperature and pressure, and development of standalone programs for users lacking training in chemical speciation problems. Extension of these methods to new applications is discussed.