Looks like they went back to a simpler solution they could deliver but with some obvious warts. good to see something get launched but the sausage making her was brutal.

The reality is that if you read https://www.allthingsdistributed.com/2026/04/s3-files-and-th..., it sounds like the great minds at S3 figured out that a caching layer was the way to go. We (EFS) fucking proposed that years ago. But we had to deal with Seattle and the S3 braintrust who didn't want to do that. I know we wrote a PRFAQ that was close to this concept probably four years ago. The political story is that EFS was taking over by S3 and the EFS folks didn't have the agency or political backing to build a more workable solution. So we wasted a shit ton of time tackling something that was never going to work and many of the tenured EFS engineers left.

formal methods. Some of this started a long time ago so not sure if it was TLA, TLA+, or something else. (I am a useless manager type)

fake clients / servers to make testing possible

strict invariants

A simulator to fuzz/fault the entire system. We didn't get this until later in the life of the service but flushed out race condition bugs that would have taken years to do.

We never got to replaying customer traffic patterns which was a pet idea of mine but probably the juice wasn't worth the squeeze.

Comments URL: https://news.ycombinator.com/item?id=45312043

Points: 5

# Comments: 6

I think many people have said this, but "file systems" get a lot easier if you don't have to worry about overwrites, appends, truncates, etc. Anyway, always interesting to see what people come up with for their use cases.

Early mobile is littered with dead operating systems. not really that surprising. PalmOS, Symbian, SaveJE, windows mobile, etc. not worth crying over.

But more importantly- mobile phones already have good security mechanisms. It's like all these shitty apps copied web based auth mechanisms with timeouts when they could do something better (and probably are built on web technologies with cookies instead of using the trusted store on the phone).

There are precious few apps out there that tell you ahead of time that reauth is happening (Zoom does this - kudos). But even so - I don't think it's necessary most of the time.

The reason the company existed is the rich founder was upset that a shop wanted to charge him a fortune to get his BMW M5 repaired. He wanted better quotes. So we built a marketplace to get better quotes. But that's not what real customers want (because most people have Toyotas not M5s). And also we didn't do the customer development / research to understand how repair shops work. You want to know how my repair shop manages their repair schedule? They have a paper calendar and write down your phone number and the job. sure there are better ways to manage the work - but this paper mechanism has worked for them for years and why change it? And you know what - I go back to the shop all the time because I trust them. Ultimately people tend to have a fairly personal relationship with their local mechanic. You can build a leadgen product but the ultimate relationship is between the customer and the repair provider.

TLDR - everyone should understand the lean startup. /working backwards model and relentlessly focus on the customer.