The problem WeBill.io solves

New GameFi users and new NFT buyers do not know how to use DEX and bridges to exchange tokens for in-game tokens or to buy NFTs for example with Matic.
With our infrastructure users can buy NFT and top up an in-game balance with any token they have on all networks, without visiting DEX, bridges, or exchanges. Also, users can pay for a subscription to in-game functions from the MetaMask wallet with any token and network of their choice.

Challenges we ran into

It is difficult to analyze all blockchains very quickly in order to find balances and tell users with which token they can pay. We needed to have all the blockchains locally and use fast databases to complete the calculation in no longer than 3 seconds for all blockchains.
In addition, it is incredibly difficult to implement the calculation of prices fixed in-game tokens for other networks. We analyze token prices on all DEXs and calculate offer prices on the backend side.