This is a brief readout of the BuilderNet Engineering Sync on 2025-06-26. That meeting is a place for operators to discuss all kinds of technical topics, from current development, ideas, issues, designs and architecture to longer term roadmap and architecture.
- Forced Azure Gen6 migration
- Azure rushes a deprecation of Gen5 TDX instances and requires a migration to Gen6 by Sept. 12, 2025 (after which Gen5 instances will not boot/reboot anymor).
- We tested the latest cvm-proxy with TCB level override, works fine . Will merge soon, tag and deploy.
- This update may be needed because Azure often provides instances with an outdated seamloader. Currently the ratio is about 1:5 outdated:up-to-date.
- Two upgrade options: (a) deploy v1.5 release with patches, (b) finalize new v1.5.1 release.
- We will see if finalizing and testing a new image is viable, in which case we will go with option b - new release. Otherwise we still fall back to option a.
- Operators need to check/request Gen6 Azure quota in relevant locations (ECEV5 vs ECEV6 quota)
- Top bid stream
- Upgrading top-bid collector, which receives bids from the relays and informs the bidding.
- Tests look good and ready for production promotion.
- Code is in the rbuilder codebase.
- Seeing an unusual 4ms delay from scraping → update. Unclear where it’s coming from, will take a look at it.
- Mempool tx optimizations
- Is currently being tested, looks all good with 50 blocks history (instead of 5). Will roll out to production on next update cycle.
- Refunds to non-EOA addresses
- Double-checking actual gas limit of payout to refund address.
- Once confirmed it’s 21k then we’ll remove the contract limitation.
- Orderflow sharing observability
- Right now there is a lack of visibility into timings of transaction propagation across BuilderNet.
- Working on a design doc for bundle recepts, so each node could record just when they saw which bundles.
- We do have several metrics for orderflow proxy latency when sending to other builders, but that’s not enough.
- Measuring relay latency
- Working on better visibility into relay latency. We don’t yet have clean metric for it, currently it also includes simulation time.
- Per-bundle refund API
- There already is an API per bundle: flashbots_getFeeRefundsByBundle
- Checking whether this is enough or if more data is needed