Argument-0005: Retention at Rank I


Report Date	2025/12/03
Submitted by	Michał Kucharczyk

Member details

Matrix username: @michal:parity.io
Polkadot address: 14T9NGF7LdCY7SK2j6oNXmB9NqfKYyrxBChUvYRjtFdvZBMo
Current rank: 1
Date of initial induction: 2024/06/02
Date of last report: 2025/09/05
Area(s) of Expertise/Interest: Substrate node ,Transaction Pool, ChainSpec/GenesisConfig

Reporting period

Start date: 2025/09/05
End date: 2025/12/03

Argument

My main focus during this reporting period was completing the PoV storage size reclaim fix. This addresses the long-standing issue #6020 where storage root calculation could cause blocks to exceed PoV budgets. I implemented incremental storage root estimation spanning runtime, state machine, and trie layers. The main challenge was performance optimization - the naive approach reduced throughput to 2% of the original. Through iterative profiling and optimization, I brought the overhead down to 2-10%. The PR is now ready for review. I documented the "full stack" profiling methodology in Reliable Flamegraphs for Substrate-Based Binaries.

The fork-aware transaction pool remains in maintenance mode. I continued with small fixes and supporting external teams encountering txpool issues: documented an instant-seal transaction inclusion race, diagnosed delayed ready events for manual-seal, and helped resolve a chain reverting issue for Anvil Node.

Additionally, I made tiny contributions to tooling and observability: wasmtime perfmap profiling support enabling proper flamegraph generation, and a new timing histogram for unfiltered InBlock events on the reliability dashboard.

Voting record

Ranks	Activity thresholds	Agreement thresholds	Member's voting activities
I	90%	N/A	None.
II	80%	N/A
III	70%	100%
IV	60%	90%
V	50%	80%
VI	40%	70%

Misc

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