Ok, as promised, my full review of the Pepper-Sync grant.
Due to the amount requested ($461,000.00) a higher bar of diligence is required.
The grant summary states:
In December of 2024, slow sync was a critical usability issue blocking Zcash adoption.
As described below, and posted on the Zcash Forums Zingo Labs produced a novel sync implementation that’s competitive with the fastest alternatives in raw performance, and was the fastest spend-before-sync implementation in production when it was completed.
In addition to the direct benefit to the community provided by a new sync implementation, there has been a salutary effect on other sync providers.
A few problems here:
- All Zcash wallets are still slow to sync. The problem remains unsolved for the ecosystem.
- Zingo has produced a somewhat faster syncing method, which has not fully solved the problem as syncing is still slow
- Zingo claims competition increased due to the presence of pepper-sync. However syncing is still slow the the problem has been largely sidestepped via optimistic UI.
- Syncing has not blocked this round of adoption. Syncing and scale in general remains a problem for Zcash, and there are other proposals in the works to solve this altogether.
So, I find it hard to accept the claim that Pepper-Sync gets to claim much, if any, credit towards solving an unsolved problem or increasing user adoption.
Justification: 2 full-time developers for 15 months at $96/hour.
I find it hard to believe that 2 full time senior engineers spent 15 months on a syncing library alone. If that is the case, I would consider it a cost overrun. I think its far more likely that much of that “full time” effort was spent on other projects at Zingo Labs.
Proof of traction
The algorithm is already deployed in four Zingo Labs applications:
zingo-cli,zingo-pc,zexcavator, andzingo-mobile.
Important to note that the grant is not for the above libraries, but that pepper-sync is used in those libraries. Let me check that.
| Product | Notes | Result |
|---|---|---|
| zexcavator | On MacOS Installs and runs on system with Rust already installed. (not user friendly for normal users that don’t have rust libraries). Both 12 and 24 word mnemonics run in to “Sync Error” and go into a restart cycle. Syncing progress is incredibly slow, probably 100x slower than most Zcash apps. Not sure that pepper-sync is solving anything here. | Fail |
| zingo-cli | Wallet loaded but UI was not clear if it was syncing or not. Could not find a way to display sync status. Transaction history empty which means sync was either unsuccessful or incomplete. | Fail |
| zingo-pc | On MacOS, the app itself is very sluggish and difficult to use. If pepper-sync is faster I wouldnt notice because I spend most of my time waiting for basic UI items to load on the screen. | Pass (slower than benchmark) |
| zingo-mobile | UI worked quickly vs. desktop. Syncing took several minutues. | Pass (slower than benchmark) |
| Zkool | As a test, I loaded the same wallet I used on the zingo products into Zkool with the same birthday height of 2905000. Zkool synced history within 30s. All the Zingo products took several minutes or did not complete during my review session. | Benchmark |
Non-Zingo Users
- ZecHub notes they used Zingo libraries for their bounties product. While pepper-sync is embedded in those libraries, they did not mention that pepper-sync in particular was a benefit to them. Application for Retroactive Funding for Pepper-Sync (second attempt) - #9 by dismad
- Shielded Labs mentioned they use Zingo libraries for their CrossLink proof of concept. While Shielded Labs notes explicitly that pepper-sync is a part of those libraries, they did not mention that pepper-sync was a requirement. Additionally, Shielded Labs has a myriad of conflicting interests with Zingo Labs due to familial and economic relationships that would warrant additional disclosures and scrutiny when applying to for grants. Application for Retroactive Funding for Pepper-Sync (second attempt) - #11 by aquietinvestor
Summary: Some to the zingo products did not work. The ones that were functional were slower at both syncing and general usage than other Zcash wallets. Based on this, am not sure that pepper-sync has added any additional utility to Zingo users or Zcash. 3rd party users did not mention pepper-sync as a useful feature.
Conflict of Interest Disclosure
Proposer left this empty.
As I have recently discovered, there is a web of familial and economic interests surrounding the applicant which I believe should be fully disclosed in this application. A non-exclusive list includes: previous dev reward recipient, shareholdings or debts related to previous dev reward or grant recipients, familial ties to previous dev reward recipients.
Additionally the Zingo Lab suite of products seems to be receiving multiple grants from multiple sources for multiple products, which makes it difficult to track any “double reimbursements”.
Given the above, I am of the opinion that Zingo Labs should disclose extensive documentation around the various grants received and for what. As well all other conflicts of interest, while not disqualifying, should be disclosed. For me, lack of disclosure is on it’s own, disqualifying.
Overall Summary
The proposal is $461,000.00 for the pepper-sync code, and nothing else. I find the library itself has not demonstrated a large value add to the ecosystem. I find the claimed cost (2x senior engineers for 15 months) to be an exaggeration or wasteful. As a voter, I do not think this proposal is a net benefit to the Zcash ecosystem, so I would vote AGAINST funding.