Founding Backend Engineer

Founding Backend Engineer

New York City Engineering / Full-time / Hybrid

Apply for this job 3Jane is building the first scalable, capital-efficient credit-based money market on Ethereum. We extend realtime USDC credit lines—backed by on-chain proofs of credit scores (via CreditKarma/zkTLS), DeFi/CEX holdings and bank (via Plaid) assets—to yield farmers, traders, businesses and AI agents. By bringing credit creation onchain (no collateral, no banks), we unlock the second pillar of modern finance for crypto and set the stage for a multi-trillion-dollar credit economy native to Ethereum. This unlocks a three-dimensional collateral space within crypto financial markets by introducing future-backed loans alongside existing asset-backed loans.
We have just raised a $5.2 million seed round led by Paradigm and are assembling an AI-native engineering team where every developer owns an entire vertical and 10×es their output through structured AI workflows. You will be the backend engineer helping to architect the core protocol end-to-end and shaping how cryptonative credit is born.

What you'll own

• 1. Core System Architecture
• Design and maintain the Convex data schema for users, balances, credit limits, and drawdowns
• Build performant systems for data ingestion, aggregation, and querying
• Implement workpool infrastructure for real-time parallel processing
• Optimize for scale, fault tolerance, and uptime
• Build internal observability: monitoring, alerting, logging
• Enforce data security and privacy around sensitive financial information
• 2. API Infrastructure & Integrations
• Build and maintain REST + GraphQL APIs powering our lending app and external partners
• Create webhook systems for streaming real-time updates
• Design APIs for credit scoring, underwriting, rewards, and loan book state
• Integrate with external data providers (Plaid, DeBank, Credit Karma, Coinbase, Reclaim, etc.)
• 3. Blockchain & Smart Contract Interfacing
• Integrate backend services with Ethereum and EVM-compatible chains
• Work with smart contracts to manage credit lines, repayments, and state sync
• Build systems for on-chain verification of off-chain data
• Support multi-chain portfolio aggregation and analytics

Must-have qualifications

• Languages & Frameworks: TypeScript/JavaScript (Node.js)
• Databases: Convex, PostgreSQL, or similar
• APIs: REST, GraphQL, webhook systems
• Cloud: AWS (KMS, Secrets Manager, Lambda)
• Security: Best practices for encryption, authentication, and data privacy
• Testing: Strong unit and integration test coverage, TDD mindset
• Bias to build: You ship fast, test in prod, document clearly, and iterate quickly

$150,000 - $250,000 a year Up to 0.5-0.75% in $JANE token supply What Success Looks Like After 12 Months 1. You’ve shipped a production-grade backend that powers real-time USDC credit lines to borrowers across DeFi, CeFi, and bank-linked rails—handling sensitive user data, credit scores, and live loan states with speed and reliability. 2. The system scales smoothly with growing borrower volume and lender TVL, showing low latency, high uptime, and well-instrumented observability.
3Jane aims to bring the engine of credit creation fully on-chain, opening a multi-trillion-dollar market and reshaping DeFi’s future. We operate as an AI-native team where every member owns an entire vertical, makes the key calls, and sees their work directly on mainnet. Backed by Paradigm and offering meaningful token equity, the role comes with outsized impact and upside from day one.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us. Apply for this job When applying, mention the word CANDYSHOP to show you read the job post completely.