Senior Software Engineer, API Products

0x•San Francisco, CA

22h•$150,000 - $230,000•Remote

About The Position

0x is hiring a Senior Software Engineer for its API Products team, which builds and maintains developer APIs for wallets, exchanges, trading apps, bridges, and developers. The team’s flagship products include Swap, Gasless, and Cross-Chain APIs, and it is developing additional tools for building trading apps. This is a hands-on individual-contributor role with ownership of projects from initial concept through production. The engineer will work on new products and existing APIs, collaborating closely with product and major customers. The position is remote, with EU time zones preferred.

Requirements

At least 6 years of backend engineering experience, including at least 2 years in DeFi at a trading app, wallet, DEX aggregator, onchain data company, or similar organization.
Senior or Lead Engineer experience with a track record of owning complex projects end to end.
Experience building and maintaining developer-facing APIs.
Deep onchain knowledge, especially EVM, including transactions, calldata, contract interfaces, gas, and approvals.
Strong system design experience for production-scale backend services.
Clear communication skills and comfort explaining technical tradeoffs to non-engineers.
Alignment with the company’s core values: do the right thing, consistently ship, and focus on long-term impact.
Ability to attend annual in-person team offsites around the globe.

Nice To Haves

Experience with cross-chain/bridging or DEX aggregation.
Experience with ecosystems outside EVM, such as Solana.
Experience with TypeScript and/or Rust.

Responsibilities

Build new APIs and trading products, from researching problems and designing architecture to shipping the first version.
Maintain and extend existing APIs, including support for new chains, bridges, and customer-requested features.
Keep APIs fast and reliable as traffic grows, and participate in the on-call rotation.
Investigate failed trades and stuck transfers using logs, traces, and onchain data, and resolve root causes.
Work with product, legal, and go-to-market teams to translate business and compliance needs into technical decisions.
Write design documents and review teammates’ designs and pull requests.

Benefits

Base salary of USD $150,000–$230,000, plus equity, ZRX tokens, and benefits.
Comprehensive medical, dental, vision, life, and disability insurance for U.S.-based employees; the company covers 100% of the base plan for employees and dependents.
401(k) and flexible spending account for U.S.-based employees.
Monthly mobile phone bill, wellness, and pre-tax transportation expenses.
Covered mental health benefits, including professional therapy sessions.
Supportive remote work environment.
Lunch reimbursement for employees globally.
Stipend for remote-work setup and gear.
12 weeks of paid parental leave.
Office in San Francisco’s Financial District for employees in the region.
Flexible vacation.