I design transaction execution infrastructure, SDKs, and reliability systems for production products

I build execution pipelines with simulation, retries, fallback handling, sponsorship flows, typed SDKs, and structured operational errors across EVM and Solana.

Transaction execution systems SDK and developer platforms Smart accounts and signing Cross-chain EVM/Solana reliability

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Live activity

joepegler:

Status

Cork, Ireland. GMT. Open to full-time, long-term contract, or selective fractional work across protocol infrastructure, transaction execution, SDKs, reliability, and developer tooling.

Track record

Execution infrastructure ownership with measurable production outcomes.

In-house account abstraction bundler

Address #1 of 15 on Etherscan

Scale: 5k to 7k swaps per day
Performance: ~30% / ~20% faster execution than Zerodev / Pimlico respectively
Reliability: ~103% success rate compared to ZD/Pimlico
Cost: Roughly 20 to 40% of execution costs (no middlemen)

Work

Built retry and fallback execution model
Debugged simulation vs execution mismatches
Identified nonce race conditions and wallet contention
Investigated RPC inconsistencies (e.g. Base chain lag)
Handles slippage, RPC lag, retries, simulation mismatches in production

Bulletproof ERC-2612 permit system

Full write-up

Reliability: Zero user-facing permit failures on supported tokens
Coverage: USDC, GHO, Morpho, OpenZeppelin, Solmate and others across 5+ chains
False positives caught: stETH, bsdETH, Morpho vaults and other tokens that pass heuristic checks but revert on permit()

Work

Two-pass detection: heuristic multicall probing, then ephemeral-key on-chain simulation
Stub-and-swap runtime pattern so users browse quotes without wallet popups
Consistent version() fallback logic across detection, simulation, and SDK signing
Self-healing batch pipeline with chunk-level error isolation

Statecraft deterministic test SDK

Project site

Problem: Ethereum integration tests often hide setup order and drift into flaky helper stacks
Approach: Typed scenario fixtures with explicit setup order and pinned chain state
Outcome: Clearer integration tests with deterministic, reproducible setup as suites grow

Work

Designed scenario pipeline primitives for TypeScript and viem-based tests
Implemented chain runtime fixtures for local and forked workflows
Documented adoption path from hook-heavy tests to explicit fixture composition
Shipped as open source with docs and runnable examples

Impact

Staff-level ownership of transaction execution, SDK architecture, and production reliability. Cork, Ireland (GMT).

Designed an internal ERC-4337 transaction orchestration architecture with parallelized fee lookup, nonce handling, sponsorship, simulation, and execution paths to reduce latency versus provider-managed flows.
Hardened sponsored and gasless transaction execution with retries, simulation, fallback handling, ABI/Sourcify-backed error decoding, and structured operational errors.
Unified multi-provider quote and execution routing across LiFi, Jupiter, 1inch, Odos, Mayan, LayerZero, and Relay behind one typed execution surface.
Led SDK architecture for smart-account, quote, and transaction execution workflows used across frontend and backend teams.
Architected Biconomy's flagship TypeScript SDK for smart accounts, modular clients, batching, signing, and multi-chain execution.
Built and open-sourced Statecraft, a TypeScript-first Ethereum integration testing framework for deterministic scenario-based tests with typed fixtures, forked state, and isolated runtimes.
Implemented EIP-712, EIP-1271, ERC-6492-style compatibility flows, and P-256/passkey-related signing support for smart-account UX.

What I build

Infrastructure and execution engineering with direct ownership from architecture through production operations.

Transaction execution infrastructure

Execution systems that coordinate fee lookup, nonce handling, sponsorship, simulation, and submit paths.

Reliability-heavy backend systems

Retry policies, fallback logic, structured operational errors, and production debugging for unstable chain conditions.

SDK and developer platforms

Typed execution surfaces, modular clients, and consistent error models that accelerate frontend and backend teams.

Smart accounts and cross-chain execution

Account abstraction, signing compatibility flows, and execution infrastructure across EVM and Solana.

Systems Built

Production execution systems and SDK platforms owned end to end.

defi.app

Web3 Infrastructure Engineer · May 2025 – Apr 2026

Owned architecture Shipped prod infra Led SDK

Problem: Users needed fast, reliable multi-chain swap and bridge flows with sponsorship, without a brittle UX.

System: Owned transaction infrastructure, sponsorship flows, execution reliability, and developer tooling for a unified cross-chain DeFi product. Built internal ERC-4337 orchestration with retries, fallback handling, EntryPoint v7 simulation, and ABI/Sourcify-backed error decoding. Unified routes across LiFi, Jupiter, 1inch, Odos, Mayan, LayerZero, and Relay with typed execution surfaces. Built EVM and Solana simulation and sponsorship infrastructure, including Jito-aware validation for sponsored transaction safety.

Result: 5k to 7k swaps/day and ~95% success rate, with 20 to 40% faster execution than Zerodev and a meaningful share of execution traffic. Slippage, state overrides, and Jito handled in production.

Bundler on Etherscan View full resume

biconomy

Lead SDK Engineer · Dec 2023 – May 2025

Led SDK direction Shipped prod infra

Problem: Teams needed one reliable way to ship smart-account product flows across chains with modern signing and strong DX.

System: Architected Biconomy's flagship TypeScript SDK from zero for account abstraction execution flows. Standardized viem modular clients with Safe support, and implemented EIP-712, EIP-1271, ERC-6492-style compatibility, and P-256/passkey-related signing flows. Hardened production readiness with typed errors, composable batching, Vitest, Bun, GitHub Actions, and Codecov.

Result: Production SDK powering gasless and account-abstracted user journeys with clear DX and maintainable test coverage.

View full resume

statecraft

Open-source side project · 2026 – Present

Owned architecture Shipped SDK Wrote docs

Problem: Full-stack teams lost velocity when integration tests depended on hidden hooks and ad hoc helpers.

System: A TypeScript-first SDK that composes explicit scenario fixtures (chain, fork, funded wallet, token balance) into one deterministic test pipeline for viem-based projects.

Result: A clearer path to deterministic integration tests, faster onboarding, and parallel-friendly suite design without replacing existing test runners.

Project site GitHub

enso

Lead Frontend Engineer · Jul 2021 – Nov 2023

Frontend architecture Primary dApp surface

Problem: Build and scale a client-facing Ethereum dApp while aligning the client with protocol/backend behavior and execution UX expectations.

System: Lead Frontend Engineer at Enso Finance. Worked on client architecture, execution-related user flows, and integration surfaces. Contributed to Graph-based product data paths and intent/routing-adjacent surfaces, collaborating with backend and protocol engineers on contracts and execution UX.

Result: Production dApp for DeFi execution workflows, with client systems integrated to backend intent/routing and execution services.

View full resume

coinflex

Head of UI/UX Engineering · Aug 2019 – Jul 2021

Directed product Shipped prod infra

Problem: Deliver a reliable, scalable trading product with a repeatable release process for a critical surface.

System: Led trading interface architecture and core feature rollout, and automated CI/CD for the interface stack to reduce release risk and improve deployment consistency.

Result: Production-grade trading UI with an automated lifecycle and higher confidence in feature delivery.

View full resume

Recommendations

Selected feedback from people I worked with directly on core infrastructure, SDK ownership, and production delivery.

"Joe owned our SDK, the core infrastructure layer powering $100M+ in daily trading volume across swaps, on-ramps, and perpetuals. He mapped external specs to our codebase faster than anyone and caught edge cases that would have broken production."

Dan Greer

Founder & CEO, Defi App · Managed Joe directly

"Joe owned the bundler and transaction pipeline end to end and led our SDK and cross-chain execution systems from early ideas to solid production releases. He brings structure to ambiguous problems and ships reliably."

Ajdin Kahrovic

Blockchain Engineer, Defi.app · Managed Joe directly

View all recommendations on LinkedIn

Contact

Transaction execution infrastructure, SDK architecture, and reliability-heavy backend systems across EVM and Solana. Open to full-time, long-term contract, or selective fractional work across protocol infrastructure, transaction execution, SDKs, reliability, and developer tooling. Cork, Ireland (GMT). Reply within 24 to 48 hours.

Get in touch View technical resume

pegler.web.services@gmail.com GitHub LinkedIn Twitter