Most blockchains still have a single-tiered network where the wallet and server are one in the same at the core level. The original NEM architecture was one of the first to efficiently design and utilize a two-tiered network. Project Catapult is the first ever announced network using Three. The lead developer working on Catapult told that; older blockchains scale linearly, one server serves only a certain amount of clients.
The new Catapult system scales exponentially as one server can feed into many API servers and the those in turn feed into many clients. This is what the blockchain should have been in the first place. Satoshi was a visionary legalist, philosopher, and economist, not so much a great network designer or coder and Bitcoin and other 1.0 chains have been dealing with problems ever since.
Expect Catapult to have the most advanced and easiest to use APIs of any blockchain. This will make XEM an attractive option for 3rd parties to build on. Catapult has been internally tested to scale to 3,000 transactions per second. It will be released as an open source solution. NEM has been under a free fall when compared to Bitcoin’s growth. The catapult project can ‘catapult’ NEM’s growth significantly.