Crossmint is a one-stop-shop developer platform for companies building onchain. We completely remove the complexity of building and using blockchain applications. Our platform provides all of the infrastructure companies need to build apps that scale to millions, without needing to orchestrate multiple vendors. It lets them create experiences that mirror the traditional web with familiar features like FaceID and email sign-ups, while eliminating gas fees and other friction points.

Our suite includes wallets, payments, onboarding, on/off ramps, tokenization, AI agent infrastructure, and other essential onchain building blocks, across 40+ blockchains.

We’re building a world where companies can get their entire blockchain backend, through a few lines of code, to build the next generation of the internet. Join us!

Location

United States: Miami; New York

Argentina: Buenos Aires

Type of employment

United States: Full-time

Argentina: Full-time employee (Contract through Deel)

Seniority

Senior (4-7 years), Principal (7+ years)

Responsibilities

As a Blockchain Engineer at Crossmint, you will be developing smart contracts, protocols, and backend integrations around them at the forefront of smart wallets, digital assets and verifiable credentials.

Your responsibilities will include:

Write high quality smart contract code: correct, gas optimized, maintainable.

Write secure code: follow security best practices, work with auditors to find bugs.

Write integration code: for the deployment, observability and maintenance of smart contracts, and/or interactions with the contracts from our backend and frontend.

Write architectural and design docs: individually and with the team.

Run your projects end to end: from conceptualization, to shipping and beyond.

Perform On-Call duties: participate in paid on-call shifts (once or twice a quarter).

Mentor new team members.

About you

To thrive in this role, you should possess the following qualifications:

Provable experience shipping high quality smart contract code.

Excellent reading and writing comprehension skills in English.

Experience working on a team and references to back it.

Educational Background: Hold a Bachelor’s degree in Computer Science or a related field, or equivalent knowledge and skills with industry experience.

Professional Experience:

2+ years of experience working on smart contract development. Reusing an existing OpenZeppelin contract for an NFT drop doesn’t count, we look for novel smart contract development experience.

2+ years working on security critical projects. We will ask you about how you ensure your code has the lowest chances of including bugs in production.

2+ years designing protocols in one of more of the following fields: blockchain applications, decentralized finance, digital credentials and identity, authentication, authorization or distributed systems.

Programming Expertise: Demonstrate expertise in multiple modern programming languages, including a focus on smart contract languages such as Solidity (p0), Rust (p1), or Move (p2).

Preferred Experience

We highly value candidates with any of the following experiences:

Security / Cryptography background: Alternatively a background in mathematics, programming or security competitions (auditing, CTF, etc).

Blockchain / smart contract knowledge on non EVM chains: Solana (rust), Sui (move), Aptos (move), or Cardano.

Onchain: Have used crypto products (collected or created digital assets, participated in Defi, or created a Farcaster profile, etc), and formed opinions about how to move the industry forward.

Published EIPs, patents, open source code or standards, or research papers in relevant areas

If you are passionate about revolutionizing payments in the NFT space and possess the skills and experience outlined above, we invite you to join us in our mission at Crossmint.

Benefits

Highly competitive location-based compensation and benefits.

Stock options program.

Unlimited, flexible PTO.

Flexible work schedule.

Company laptop and allowance for any necessary home equipment.

Daily stipend for commuting to the office.

Company-paid trips for annual off-sites and onsites.

Our Principles

Results and delivery: we value shipping: high quality and impactful code. We don’t care how you get it done.

Build for the long term: we value building systems that stand the passage of time: scalable, secure, and reliable solutions.

Extreme Ownership: we look for individuals with high agency, self motivated and driven who can own their projects end to end and help push the company forward.

Be a team player: we look for kind individuals who can work in a team effectively, and also upskill the team they work on. In this role we specifically value mentorship ability.