@Jan: real-time transaction management system means a financial system, where transactions must be relayed between financial entities and payment providers. Basically all financial action you or your company is involved when dealing with money. Loans, reconciliations, transfers, asset management, etc. Fragmented in space and time of course restricted by hundreds of business rules and standards involving multiple transfer formats... Java has no chance to outperform Node in I/O operations. About computational power, JS is not designed to calculate heavy math-related complex structures, but you invoke some C++ library for it for performance beyond the reach of native Java. NodeJS is not for everything, but definitely not a toy anymore. It is a real EE key player not smaller than Java even if the focus is deviating.