Original post
The Smart Contratcs solution is comming soom in IOTA, like the post on REDDIT. “A smart contract is a computer protocol intended to facilitate, verify, or enforce the negotiation or performance of a contract. Smart contracts were first proposed by Nick Szabo in 1996. Proponents of smart contracts claim that many kinds of contractual clauses may be made partially or fully self-executing, self-enforcing, or both. The aim with smart contracts is to provide security that is superior to traditional contract law and to reduce other transaction costs associated with contracting. Smart contracts have been used primarily in association with cryptocurrencies. The most prominent smart contract implementation is the Ethereum blockchain platform,[2] where they are known as a decentralized application (dapp, stylized ĐApp). (Wikipedia)
According to user Bingx, in the same post on REDDIT

“The tangle architecture of IOTA brings some unique advantages but also disadvantages. One disadvantage is that the order of transactions is not always easily determined.

In traditional blockchain, all transactions in say block #78 clearly happened before the transactions in block #79. In the tangle, two transactions can happen almost at the same time but it won’t be immediately clear which one happened first. Only if there is a directed path in the tangle between the two it can be determined. Watching this site a bit makes it more clear: https://tangle.blox.pm/
There are different types of smart contracts. Some don’t care whether transaction A called contract C before transaction B (say a voting contract) but lots of other contracts do care about it.
To solve this problem the IOTA foundation is working on implementing oracles which can provide timestamps of transactions. See roadmap here: https://blog.iota.org/iota-development-roadmap-74741f37ed01 If the timestamp of a transaction can be determined then an ordering can be determined and therefore a smart contract platform similar to the Ethereum virtual machine can be implemented.”