Blockchain QA Engineer at Largeton Group

Summary

Blockchain QA Engineer

Ensure correctness, security, and reliability of a verifiable financial data platform anchored to blockchain.
Validate data-heavy pipelines and ensure ISO 20022 semantic consistency.
Test blockchain attestation logic, including cryptographic proofs and smart contracts.
Validate end-to-end chain of custody for financial records: canonicalization, cryptographic integrity, blockchain attestations, selective disclosure, and reconciliation.
Design, implement, and maintain automated test suites for backend APIs (Golang), smart contracts (Solidity/EVM), and data pipelines (ETL/normalization).
Conduct rigorous manual testing for complex financial transaction edge cases.
Perform functional and security testing of smart contracts; validate on-chain state transitions and event emissions.
Test scenarios involving chain reorganizations, gas spikes, network latency, and failed attestations using tools like Hardhat, Foundry, or Truffle.
Validate ISO 20022 semantic mapping and perform differential testing to ensure data fidelity.
Test Merkle tree construction and proof inclusion logic.
Conduct load and fuzz testing on data ingestion, proof-generation services, smart contracts, and API endpoints.
Collaborate with Cybersecurity to validate identity and provenance layers.
Integrate blockchain testing into CI/CD pipelines (ArgoCD/GitHub Actions).
Develop custom scripts (Python, Go, JS) for test data and event stream simulation.
Track and document bugs, providing clear reproduction steps.

4+ years of QA/SDET experience
2+ years in blockchain/Web3 QA
Proficiency in at least one programming language (Golang, Python, JS/TS)
Experience with blockchain testing frameworks (Foundry, Hardhat)
Experience with API testing tools and cryptographic primitives
Bachelor's degree in Computer Science, Engineering, or related field; advanced degrees or MBAs are a plus

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