Blockchain Engineer

Salary

salary72,000€ - 90,000

Skills

Location

We offer relocation pack

Languages

Fluent English

Job Description

As a Blockchain Engineer (Smart Contracts) at Openfort, you’ll take large areas of ownership across our onchain product surface: smart contracts, wallet/vault architecture, and the developer experience around them. Because we build developer tooling, engineering and product are tightly connected. We value simple primitives, intuitive APIs, and rapid iteration. This isn’t just about shipping contracts — it’s about turning complex wallet infrastructure into something developers love.

What you’ll do

  1. Design, build, and ship Solidity smart contracts that power wallets, vaults, and account systems (upgradeability, access control, permissions, sessions, spend limits, etc.).
  2. Own end-to-end product features from spec → contract architecture → implementation → testing → deployment → monitoring, driven by real user needs.
  3. Build wallet/vault primitives with a strong security mindset: key management patterns, recovery flows, signing/authorization, modular permissions, and safe upgrade paths.
  4. Collaborate closely with product and platform teams to shape clean developer-facing interfaces (SDK/API integration points, contract ABIs, standards alignment).
  5. Enforce smart contract best practices: code quality, audits readiness, property-based testing, threat modeling, and gas/performance tradeoffs.
  6. Iterate quickly: prototype, validate with users, and refine designs without over-engineering.

Your profile

  1. 4+ years of engineering experience, with strong Solidity smart contract development experience in production.
  2. Product-oriented: you care about UX/DX, tradeoffs, and shipping improvements that users actually feel.
  3. Proven track record building secure onchain systems (wallets, vaults, DeFi primitives, auth/permissioning, or similar).
  4. Comfortable with modern smart contract workflows: Foundry/Hardhat, unit + invariant tests, CI, deployments, monitoring.
  5. Strong understanding of Ethereum architecture, EVM behavior, common attack vectors, and audit-style thinking.
  6. You’re an engineer, not a manager.

Nice to haves

  1. Experience with wallet or vault design (account abstraction patterns, session keys, recovery, spend policies, multisigs, permissions frameworks).
  2. Familiarity with Rust (optional) and/or Solana programs (optional).
  3. Contributions to open-source developer tooling (contracts, SDKs, libraries, standards).
  4. Recognition in competitive realms (CTFs, hackathons, coding contests).

Hiring Process

  1. Culture fit
  2. Technical challenge (4h)
  3. Technical interview
  4. Reference calls
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Openfort

At Openfort, we’re building the infrastructure developers need to interact with internet money. We help our clients build with authentication, wallets and payments so they can focus on building systems and experiences that improve the speed and ownership of money around the globe.

We’re committed to reshape the internet by making ownership and sovereign economies a reality.

So what are we doing differently?

We've crafted a better way for developers to interact with the blockchains. By enabling developers with creative tools and drastically simplifying the go-to-market for projects, we make the blockchain space reachable for newcomers.

  1. We are developers first. Developers craft delightful experiences that don’t get in the way without compromising custody.
  2. We serve the app layer. We are focused on an industries that already moves hundreds millions of dollars worth of digital assets and stablecoins.
  3. Participate in public goods. We leverage technology standards that scale what developers can do with digital assets.

Who are we?

Fuelled by a $3M investment from top-tier VCs, we're expanding our team, led by our founders Joan (CEO) and Jaume (CTO).

Why you should join us

Ownership matters

Money has not evolved in the last 100 years. Everything you could do with it, exchanging, buying, sending, etc. still uses archaic technology systems build under custody of a few. The evolution of internet and programmable money means our relationship with money is also evolving.

The modern world has been built on the idea that ordinary people don’t want to own their financials. We can change the way we access financials products, more opportunities and upside. And that matters.

And because it matters, we ship every single week to tilt the world in favor of owners.

You’ll solve some of the most interesting technical problems of our time.

We’re at a magic moment

This is the most incredible time in the company’s trajectory, and we will build a role custom to you as a foundational member. Working at Openfort isn’t for everyone. And that’s okay. This is a place for people who want to be the best at what they do and who want to dedicate their career to our mission of tilting the world in favor of people who want to own their financial freedom.

The team you build is the company you build.

Every week, three goals guide us: work hard, advance the mission, and have fun—because fun is good for business. We work from our office in Barcelona.

You’ll learn how to create a company.

Our Core Values

  1. Dream Big We are on a path to change the world for the better. We create and communicate a bold direction that inspires a life-changing vision. We don’t sacrifice long-term value for short-term results.
  2. Olympian’s Work Ethic Changing the world never comes easy. We work harder, longer, and smarter, not just two out of three. We put everything we have on the field.
  3. Growth Mindset We confront the toughest challenges head-on and persevere. Sometimes we fail, but we brush ourselves off, adapt, learn, and push forward with resilience.
  4. Customer Obsession We go the extra mile for our Developers and Business partners. We remain focused on delivering high-quality infrastructure and services that will revolutionize tech.

Photos

About the team

6

employees

26

avg. age

4

nationalities

Benefits and perks

  • stocks

    Stocks options

  • food

    Food & drinks

Location

Av. Roma, 159, Barcelona, Spain