KrakenD is a stateless, distributed, high-performance API Gateway that helps you effortlessly adopt microservices
KrakenD is a high-performance API Gateway optimized for resource efficiency, capable of managing 70,000 requests per second on a single instance. The stateless architecture allows for straightforward, linear scalability, eliminating the need for complex coordination or database maintenance.
WebLOQ IO is a Java NIO framework which allows for tens of thousands of concurrent TCP/IP connections through a very small threadpool (assuming proper OS and network settings). There is built in support for SSL and non-SSL connections.