Blockchain Engineer
Remote (U.S.) — Full Time
The Cari Network is building a blockchain-based payment system powering real-time, 24/7 movement of digital money across the traditional finance and digital asset ecosystems. A pre-launch startup, we're creating an entirely new category of financial infrastructure that brings cash on chain through tokenization while powering the full spectrum of payments for our network—banks, digital asset exchanges, and, most importantly, the customers they serve.
About the Role
You'll work within the systems that take a payment instruction and turn it into an immutable, on-chain record—implementing features and extensions within an established transaction pipeline architecture, alongside senior engineers who own its design. That means building out pieces of the integration layer between our backend services and our institutional custody platform, and contributing to transaction integrity from calldata construction through on-chain finality on our private ZKsync-based L2.
You'll also work directly in our smart contract suite, extending existing contracts under established upgrade-safety and role-governance patterns, and building the audit trail and compliance evidence that regulated bank partners require.
What You'll Do
Implement components of the transaction lifecycle: calldata construction, custody platform signing requests, nonce handling, L2 submission, and finality confirmation, working within the pipeline architecture senior engineers on the team have designed
Build features within the signing pipeline—new submission paths, throughput handling against custody platform rate limits, async transaction submission logic—under existing architectural patterns
Implement payment integrity controls: commitment hash verification at pipeline handoff points and co-signer policy evaluation logic
Extend our Solidity smart contracts, following established upgrade-safety, storage-layout, and role-governance conventions
Contribute to the custody platform authorization policy integration and co-signer agent for custodian-owned transaction authorization
Build structured audit trail logging from transaction origination through on-chain execution, satisfying evidentiary requirements for bank partners under regulatory oversight
Contribute to the async transaction queue supporting tiered SLAs and per-bank throughput quotas
Write high-coverage tests across backend services and smart contracts, maintaining our coverage threshold
Participate in on-call, working through known issue patterns independently and escalating novel failure modes to senior engineers
Qualifications
3–5 years of backend software engineering experience, with 1–2 years working directly on EVM-compatible blockchain systems
Solid proficiency in TypeScript; familiarity with Effect (effect.ts) or a comparable functional effect system is a plus
Working familiarity with EVM transaction mechanics: ABI encoding, nonce management, gas estimation, revert handling, and event decoding
Some production experience with Solidity smart contract development, including exposure to upgradeable proxy patterns (UUPS) and OpenZeppelin contract libraries
Exposure to institutional custody or key management APIs is a strong plus, though not required
Understanding of idempotency, at-least-once delivery, and crash recovery concepts in async systems
Comfortable asking for help extending existing patterns while building toward independent ownership of larger features
Nice to Haves
Experience with ZKsync or ZK Stack-based chains—particularly developer-facing constraints like calldata handling, system contract interactions, and AA transaction formats
Familiarity with Kafka or message-queue-backed async pipelines
Prior work in fintech, payments, or any regulated financial infrastructure environment
Foundry proficiency (forge test, forge fmt)
What We Offer
Competitive compensation
Remote-first work environment
Opportunity to shape a market-defining protocol with an experienced founding team
Meaningful influence over product design at the earliest stage
Interested in this role? Send us your resume.