Comment by Uptrenda

The blockchain industry is basically founded on incompetence. If you go back to early Silk Road and Mtgox you can see some shocking things. Like the founders were posting questions on Stackoverflow about database basics. They then ended up building systems with race conditions (withdrawal code for both systems.)

See, if you're an engineer (from a web background) you might think that using a regular backend language with a relational DB would be fine. But this service is typically optimized for concurrency. That might sound amazing. But what you really want is a simple queue. This ensures everything is applied in order and makes it impossible to accidentally have transactions execute on stale state. Plus, a queue can be executed amazingly fast -- we're talking Nasdaq scales. If you use a standard DB you'll end up doing many horrible broken hacks to simulate what would be trivial engineering had you used the right design from the start.

You've got other things to worry about, too. Financial code needs to use integer math for everything. Floating point and 'decimals' lead to unexpected results. The biggest complexity with running large-scale blockchain services is having to protect 'hot wallets.' Whenever an exchange or payment system is hacked the target is always the funds that sit on the server. When the industry began there were still many ways to protect the security of these hot wallets. The trouble is: it required effort to implement and these protocols weren't widely known. So you would get drive-by exchanges that handled millions of dollars with private keys sitting on servers ready to be stolen...

Today there are many improvements for security. New cryptographic constructs like threshold ECDSA, hardware wallets, hardware key management (like enclaves), smart contract systems (decentralized secret sharing... and even multi-sig can go a long way), and designs that are made to be decentralized that remove the need for a centralized deposit system (still needs some level of centralization when trading to a stable coin but its better than nothing.)

I would say the era where people 'build' ledgers though is kind of over. To me it appears that we're organizing around a super-node structure where all the large 'apps' handle their own changes off-chain (or alternatively based on regular trust.) The bottom layer will still support payments but it will be used less often. With more transaction activity happening on layers above. I think its still important to scale the chain and make it as secure as possible. Bitcoin has a unique focus here on security above everything else. Making it ideal for long-term hedges. For every day stuff I can't think of any chains that have more credible R & D than Ethereum. They seem to even have been doing research on the P2P layer now which traditionally no one has cared about.