Senior Software Engineer, API Products

0x; United States; Remote; USD 150,000 - 230,000; Full time

Benefits offered by this job

Medical/Dental/Vision/Life insurance

401k matching

Monthly mobile bill

Mental health benefits

Remote-friendly environment

Lunch reimbursement

Remote work setup stipend

Parental leave (12 weeks)

SF-area office access

Generous vacation

Job summary

0x is hiring a Senior Software Engineer to lead API product development and scale our backend services for blockchain trading. You will own projects end-to-end, collaborating with product teams and major customers, while delivering reliable APIs across multiple chains.

This hands-on IC role offers ownership with minimal direction and a remote-first and EU-timezone-friendly setup. The role emphasizes building developer-facing APIs, maintaining fast performance, and contributing to architecture

Qualifications

• 6+ years of backend engineering experience, including 2+ years in DeFi at a trading app, wallet, DEX aggregator, or onchain data company.
• Senior or Lead Engineer with ownership of complex projects end to end.
• Built and maintained developer-facing APIs.
• Deep onchain knowledge, especially EVM: transactions, calldata, interfaces, gas, approvals.
• Strong system design experience for production-scale backend services.
• You’re an AI power user who enhances impact without replacing judgment.
• Clear communicator, able to explain tradeoffs to non-engineers.
• Aligned with values: do the right thing, ship, and focus on long-term impact.
• Able to attend annual in-person team offsites globally.

Responsibilities

• Build new APIs and trading products from research to shipping the first version.
• Maintain and extend existing APIs for new chains, bridges, and features.
• Keep APIs fast and reliable as traffic grows and participate in on-call rotation.
• Investigate failed trades and transfers using logs, traces, and onchain data.
• Collaborate with product, legal, and GTM to translate business needs into tech decisions.
• Write design documents and review peers’ designs and pull requests.

Skills

Backend engineering

DeFi experience

Senior/Lead engineer

APIs for developers

On-chain knowledge

System design

AI power user

Communication skills

Core values alignment

Offsite travel

Tools

TypeScript

Rust

Job description

COMPANY

At 0x, our mission is to "Create a Tokenized World Where All Forms of Value Can Flow Freely". We deliver this to web3 builders with a delightfully simple suite of developer APIs that provide faster trading, better prices, and superior user experience.

Founded in 2017, we’ve processed over 211M+ transactions and $180B+ in trading volume from users trading on Matcha, Coinbase Wallet, Robinhood Wallet, Phantom, Rainbow, DefiLlama, MetaMask, Zerion, Zapper, and many more. Our investors include Greylock Partners, Pantera Capital, and Jump Crypto.

When you join 0x, you’ll become part of a veteran team of crypto builders who know the importance of code quality, team cohesion, and a culture of learning.

About the team

Behind every 0x trade is a lot of hard work. We integrate hundreds of liquidity sources, optimize for gas, slippage and latency, split routes and simulate every result to get traders the best possible outcome. The API Products team turns that routing logic into easy-to-integrate APIs that wallets, exchanges, trading apps, bridges and developers around the world rely on.

This team of four built, maintains and continues to evolve our flagship Swap, Gasless and Cross-Chain APIs, which have moved billions in volume. Next, they’re building new products that give developers even more tools for building trading apps.

About the role

We’re hiring a Senior Software Engineer to expand what the API Products team can take on. You’ll lead projects from first idea to production, on new products and on the APIs that are already live, working closely with our product team and some of our biggest customers. This is a hands-on IC role for someone who wants real ownership and works well with little direction. Remote, EU timezones preferred.

What you’ll do

• Build new APIs and trading products, from researching the problem and designing the architecture to shipping the first version.

• Maintain and extend our existing APIs, including support for new chains, bridges and customer-requested features.

• Keep our 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 the root cause.

• Work with product, legal and GTM, turning business and compliance needs into technical decisions.

• Write design documents for your work and review your teammates’ designs and pull requests.

Who you are

• 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.

• Senior or Lead Engineer with a track record of owning complex projects end to end.

• Built and maintained developer-facing APIs.

• Deep onchain knowledge, especially EVM: how transactions work, including calldata, contract interfaces, gas and approvals.

• Strong system design experience for production-scale backend services.

• You’re an AI power user who uses it to multiply your impact as an engineer, yet you don’t let it replace your judgment.

• Clear communicator, comfortable explaining technical tradeoffs to non-engineers.

• Aligned with our core values: do the right thing, consistently ship, and focus on long-term impact.

• Able to attend annual in-person team offsites around the globe.

Nice to have

• Experience with cross-chain/bridging, or DEX aggregation.

• Experience with other ecosystems outside of EVM such as Solana.

• Experience with TypeScript and/or Rust, our main languages.

BENEFITS

• The base salary range for this position is USD $150,000 - $230,000 + equity + ZRX tokens + benefits. Within the range, individual pay is determined by job-related skills, experience, location, business needs, and candidate preferences between the different compensation elements.

• Comprehensive insurance (medical/dental/vision/life/disability) for U.S.-based employees - 100% of base plan covered for you and dependents

• 401k and FSA for U.S.-based employees

• Monthly mobile phone bill, wellness, and pre-tax transportation expense

• Covered mental health benefits (included professional therapy sessions)

• A supportive remote environment

• Lunch reimbursement for all employees across the globe!

• Stipend for your ideal remote / WFH set-up: headphones, and any other work gear you may need

• 12-week paid parental leave

• Great office conveniently located in the SF Financial District for those in the region!

• Flexible vacation: Take time when you need it (and we really mean it!)

0x and its associated entities are dedicated to fostering diversity, inclusion, and belonging in its teams and workforce, and are proud to be equal opportunity employers. 0x does not make employment or hiring decisions on the basis of race, color, creed, religion, sex (including those who are pregnant or have given birth), sexual orientation, gender, gender expression or identity, age, disability, medical condition, genetic information, military or veteran status, marital status, pregnancy, citizenship, national origin, immigration or citizenship status, political affiliation, or any other basis that is protected by applicable local, state, or federal laws. This includes not making such decisions based on the status itself, as well as any associations, perceptions, and assumptions made regarding these statuses. 0x will also consider qualified applicants with arrest and conviction records in a way that is consistent with San Francisco’s Fair Chance Ordinance and similar local laws. Our commitment to equal employment opportunity extends to ensuring that all applicants and employees can perform to their fullest potential, including through obtaining reasonable accommodations when necessary.