Essential Tools for Ethereum Block Builders

Published: building

The block building game on Ethereum is a relatively new and ever-changing field, continually reshaped by the influx and exit of diverse players with different motives and incentives. Admist this dynamic environment, one constant prevails: the top competitors in this space often leverage certain tools, one of which will be discussed in this blogpost.

Disclaimer: Special thanks to bloXroute for letting us trial their services, their support has been instrumental in our journey


Since our last post, penguinbuild has been building ~1.8% of the blockspace for the last 30 days.

And on good days, we might even break even!


A pivotal tool we found for block building is bloXroute.

In the previous article, we briefly touched on the impact bloXroute had on our operations. Though at the time, we lacked the data to back it up our claims. Now, after ~50 days in operation, we are excited to share our findings.


A brief recap on bloXroute's Blockchain Distribution Network (BDN) - this is a network specifically designed to propagate blockchain related transactions.

Using bloXroute's BDN helped us in two ways:

So, to test out the impact of the BDN, we had two identical block builders with different block graffiti (extradata):

Note that even though these servers are located in different regions, the responsibility for producing each block graffiti gets rotated every few days.

The Graffiti Speaks For Itself

blocks produced by 4801
blocks produced by 1362

Testing in production, the builder connected to the BDN is x3.5 times more likely to have their block bid approved!

Side note: We've built over 5,000 blocks! Here's to the next 5,000 more.


Block building is not just about building the best block, it also about being able to bid for the best block. As a builder, having a reliable connection to the relay is just as important as having the fastest transactions from the mempool.

Among the leading relayers in the space are: ultrasound and bloXroute. These two stand out for good reason.

They're among the select few relays with a websocket connection, a key feature that enables you to stream top bids for the current slot - a crucial aspect for real-time bid analysis and response.

It's important to emphasize: we're talking about websocket connectinos, not HTTP. This distinction is critical for performance.

For instance, to stream the top bids for the current slot from bloXroute, the MEVBlockValue stream API comes into play. You can also customize your websocket subscribtion to receive auxiliary data such as gas_used, or builder_pubkey. The latter is especially useful if you have multiple builders public keys.

Being able to stream incoming bids as they happen instead of polling for them has reduced the latency from 50ms to ~10ms. This x5 fold decrease in response time has helped us significantly in analyzing and refining our block bidding stratgies.

Moreover, not only are ultrasound and bloXroute innovating in this area, but they're also one of the few relays that has the infrastructure to support a sudden spike in traffic without imposing rate limits. (Note that the HTTPS endpoint is still subjected to rate limiting.)


In summary, bloXroute's support has been instrumental in our block building journey, as a thank you for the trial, CrypticWoods would like to award them Essential Block Building Tools (2023) award.