> But it’s not solvable, not really. It’s part of the domain, it’s not going anywhere, it’s irreducible complexity. You _will_ have conflicts (because your app is distributed and there are concurrent writes). [...] Another misconception is that conflict resolution needs to be “solved” perfectly before any progress can be made. That is not true as well. You might have unhandled conflicts in your system and still have a working, useful, successful product. Conflicts might be rare, insignificant, or people (your users) will just correct for/work around them.

I can't speak for whatever application-level problems you were trying to solve, but many problem-cases can be massaged into being conflict-free by adding constraints (or rather: discovering constraints inherent in the business-domain you can use). For example (and the best example, too) is to use an append-only logical model: then the synchronization problem reduces down to merge-sort. Another kind of constraint might be to simply disallow "edit" access to local data when working-offline (without a prior lock or lease being taken) but still allowing "create".

> Database (or any other magical tool) can’t do it for you.

Yes-and-no.

While I'm no fan of CORBA and COM+ (...or SOAP, or WS-OhGodMakeItStop), but being "enterprise-y" it meant they brought distributed-transactions to any application, and that includes RDBMS-mediated distributed transactions (let's agree, an RDBMS is in a far greater position to be a better canonical transaction-server than an application-server running in-front of it). For distributed systems needing transient distributed locks to prevent conflicts in the first place (so only used by interactive users in the same LAN, really) this worked just-as-well as a local-only solution - and make it fault-tolerant too.

...so it is unfortunate that with the (absolutely justified) back-to-basics approach with REST[1] that we lose built-in support for distributed transactions (even some of the more useful and legitimate parts of WebDAV (and so, piggy-backing on our web-servers' built-in support for WebDAV verbs) seem to be going-away) - this all raises the barrier-to-entry for doing distributed-transactions _right_, which means the next set of college-hires won't have been exposed to it, which means it won't be a standard expected feature in the next major internal application they'll write for your org, which means you'll either have a race-condition impacting a multi-billion-dollar business thing that no-one knows how to fix or more likely, just a crappy UX where you have to tell your users not to reload the page too quickly "just in case". Yes, I see advisories like that in the Zendesk pages of the next line-of-business SaaS you'll be voluntold to integrate into your org.

(I think today, the "best" way to handle distributed-locking between interactive-users in a web-app would necessitate using a ServiceWorker using WebRTC, SSE, or a highly-reliable WebSocket - which itself is a load of work right there - and don't forget to do all your JS feature-checks because eventually someone will try to use your app on an old Safari edition because they want to keep on using their vintage Mac) - or anyone using Incognito mode, _gah_.

[1]: https://devblast.com/b/calling-your-web-api-restful-youre-do...