Background information of the applicant
My name is Stephen Lawrence, a software engineer with years of experience building and operating complex software systems. I'm deeply passionate about open source, and much of my work involves contributing to both Web2 and Web3 projects. My journey into the Polkadot ecosystem started with the SDK, an interest that was sparked during a workshop previously organized by Polkadot Africa. That experience really opened my eyes to the possibilities within the ecosystem, and I've been contributing consistently ever since.
Motivation(s) for applying to the Polkadot Technical Fellowship
As I've contributed more deeply to the SDK, I've developed a strong sense of ownership over the quality and reliability of the codebase. Over the past months my work has moved from isolated feature additions into the parts of the stack that runtimes actually depend on in production: staking and election payouts on Asset Hub, XCM dry running, offchain state tooling, and the remote proxy path in the Fellowship runtimes. Joining the Fellowship feels like the right way to formalize that commitment, taking on greater responsibility, upholding high technical standards, and contributing to the long term sustainability of the infrastructure we all depend on.
Area(s) of interest in relation to the Polkadot ecosystem
Contribution(s) to Polkadot SDK
[EPMB] Configurable reward source and slash destination for the signed phase (PR 12843, merged). I introduced type RewardSource and type Slash to pallet-election-provider-multi-block::signed::Config so signed submission rewards are paid from a pot account instead of being minted, and slashed deposits are routed to a handler instead of being burned. This keeps TotalIssuance reconcilable with the DAP emission curve on Asset Hub. The change was backported to stable2609.
pallet-accumulate-and-forward: measure the transfer period from the last forward (PR 13153, merged). on_idle required the block number to be an exact multiple of TransferPeriod, which a parachain reading the relay chain block number can miss indefinitely, stalling forwarding. It now records the block of the last forwarding attempt and forwards once the period has elapsed. Backported to stable2606 and stable2609.
pallet-xcm: fix dry run storage side effects leaking into xcm-emulator (PR 12807, merged). dry_run_call and dry_run_xcm mutated caller state, so dry run outbound messages were silently delivered by process_messages() in the emulator. Both are now wrapped in a rolled back storage transaction, so simulation no longer has real effects.
remote-ext: fix silent state corruption from lagging RPC providers (PR 12268, merged). Per item RPC errors were being treated as empty values, producing silently incomplete snapshots for try-runtime and testing. Errors are now treated as batch failures, the computed storage root is verified against the block header before a snapshot is cached, and providers that lack the target block are excluded up front.
[EPMB] Let DAP own and authorise payouts from its buffer (issue 13127, open, in progress). I opened and scoped this off the back of review discussion on PR 12843 with @sigurpol, who reviewed that PR in depth and helped shape the direction. DAP already owns deactivation on inflow, so reactivation on outflow belongs there too. The proposal registers the signed phase pot in DAP as a capped recipient and moves the payout plus the reactivation into DAP, so the pallet requests a payment instead of drawing on the pot itself. I am actively working on this now and the implementation is open for review at PR 13173.
Ensure broker parachain reachability in coretime benchmarks (PR 11080, approved). Uses SendXcm::ensure_successful_delivery() so the required XCM routing infrastructure is initialized before the coretime benchmarks run.
frame-benchmarking: refactor the pallet benchmarking backend (PR 11758, approved). Deduplicates the analysis logic, formalizes BenchmarkBatch::split(), improves API ergonomics, error handling and documentation, and deprecates the v1 macro system in favour of v2.
frame-system: require explicit weight configuration in default configs (PR 10901, approved, second review pending). SystemWeightInfo and ExtensionsWeightInfo are marked #[pallet::no_default] and lose their () defaults, so runtimes can no longer silently inherit the Substrate reference weights and must set their own benchmarked values.
pallet_balances: remove FreezeIdentifier and MaxFreezes in favour of RuntimeFreezeReason (PR 12900, approved). RuntimeFreezeReason becomes the freeze identifier and bounds Freezes with its variant count, retiring two redundant config items and the integrity test that policed them across all runtimes.
pallet-broker: add an extrinsic to register a potential renewal (PR 10824, approved). Gives network administrators, especially in testnet and governance contexts, direct control over coretime renewals, making it easier to manage allocations and schedule renewals with precision.
Deprecating the para_id field from chain specifications (PR 7546, closed). My PR laid the groundwork by introducing the idea of retrieving the parachain ID via a runtime API. That direction was later expanded on and fully realized in PR 8651, which completed the transition to a dynamic, runtime driven approach.
Contribution(s) to the Fellowship runtimes
Fix remote proxy dropping the newest relay root when multiple parachain blocks share a relay parent (PR 1234, merged). pallet-remote-proxy skipped duplicate BlockToRoot entries for the same relay parent and evicted the oldest entry instead of the newest when the bounded vector was full, so remote proxy proofs anchored at recent relay blocks failed with UnknownProofAnchorBlock. This closed issue 1230.
Wire pallet-election-provider-multi-block Slash/RewardSource to DAP on Polkadot Asset Hub (issue 1239, open). Polkadot Asset Hub needs the same wiring that PR 12843 added for Westend Asset Hub, so I filed and scoped the follow up here for the next polkadot-sdk bump, again alongside @sigurpol, who is carrying it with me.
Ongoing contributions
These cover, among others, try_state invariant checks for a set of pallets (proxy, multisig, vesting, identity, preimage, scheduler, whitelist, salary), the Currency to fungible migrations across alliance, society, vesting, democracy, assets, nfts and uniques, the scheduler overweight task handling fix, and the VersionedCall refactor for pallets that store calls.
Link to the GitHub profile of the applicant
https://github.com/Stephenlawrence00
Polkadot address with a verified on-chain identity
16Xj1rSgNBtzHch3Jb9SfW7dK749s9WbCqKcwmZCFkR2pnai