Senior Engineer

You will write a large share of the code that matters most, and you will join the team who decides how it is built.

This is a hands on engineering seat. We are asking you to be a strong technical mind on the systems you own, executing everything from infrastructure, backend and frontend.

You'll report directly to the CTO.

Shipped product. You will be one of the highest output engineers on the team, working across the stack on the features and services our customers depend on. Half of what we need from you is simply excellent code, delivered fast, in production.

The architecture of what you build. You get to design the systems you own: data models, service boundaries, APIs, failure modes, and the tradeoffs behind them. You write the decisions down so the next engineer understands why, not only what.

Quality as a system, not as a personal habit. Testing strategy, review standards, CI discipline, observability. Our customers are regulated companies so correctness and security are important product features here, not hygiene.

Technical expertise. You raise the level of the engineers around you through design review, code review and pairing.

We care more about how you think than about the boxes on your CV. There are two things we won't compromise on. Everything after them is experience we value.

Where we hold the line

• You learn fast. You can point to a time you went from not knowing a domain, language or spec to shipping in it, and tell us how long it took.
• You think analytically. You break messy problems into parts, reason from first principles, and defend a tradeoff with evidence rather than preference.

Experience we value

• Several years building production software, mostly hands on. Around 8 years is our reference point. If you moved into management, you were still writing significant code recently.
• Proven development, shipping and architecture. You have designed and built at least one complex system end to end. You can walk us through the alternatives you rejected, what you got wrong and what you would change.
• Full stack ownership. You have taken features from data model to user interface in production.
• Go, or a language that carries over. Go is our main backend language. Solid experience in Java, C#, TypeScript, Python or another object-oriented language counts.
• Shipping fast without shipping badly. You can name the practices (tests, review, instrumentation, scoping) that let you move quickly and safely.
• Coding with AI. AI assistants are part of how you work every day, and you know where they speed you up and where their output needs checking.
• Building against formal specs. ETSI, W3C, ISO, IETF, OpenID Foundation or similar. You know how to handle the gap between what the spec says and what real implementations do.
• Strict security environments. You have worked where a bug costs more than a bad user experience.

• Experience in identity, cryptography, authentication, KYC or fraud prevention
• Experience in a regulated environment: banking, fintech, iGaming, health or public sector
• Familiarity with EU regulatory frameworks relevant to digital identity (GDPR, eIDAS 2.0)
• Experience at seed to Series B stage, where you chose what not to build as often as what to build
• Open source contributions or technical writing we can read

• By month 3, you have shipped meaningful features to production on your own, and you understand our systems well enough to disagree with how they are built.
• By month 6, you own at least one critical system end to end, including its architecture, its tests and its behaviour in production.
• By month 9, architecture decisions in your area are documented and made by you
• By month 12, other engineers consult you before they build, because your feedback is valuable to deliver faster and better output.

We do not measure engineers by ticket counts or story points. We measure whether the systems you own are reliable, whether the people around you get better, and whether we ship faster because you are here.

We list this so you know what you are walking into.

• Infrastructure: cloud based, running on Kubernetes, with services containerised in Docker and organised as microservices.
• Backend: Go.
• Frontend: React for web, React Native for mobile.
• Identity standards: OpenID4VCI, OpenID4VP, SD-JWT VC, ISO/IEC 18013-5 mdoc and the EUDI Wallet Architecture and Reference Framework.

We're building this role around the right person. Base and equity will be benchmarked to your experience and the market.

Indicative range: 40.000-55.000€

1. Join a genuinely great, international team that takes the work seriously and itself less so.
2. Work with high impact, cutting-edge technologies.
3. High-growth environment with meaningful career development opportunities.
4. Flexible schedule and remote-work options.

Gataca builds digital identity infrastructure that helps regulated companies onboard customers in one click while meeting the security and compliance standards their industries demand.

Companies that verify user identity have relied on the same online verification model for years. That model is breaking down quickly under generative AI, and the response from most vendors has been to stack on more friction: reCAPTCHAs, OTPs, requests for additional documentation. Every extra step in a sign-up flow costs conversions, which leaves companies with a bad trade: add friction and lose revenue, or accept more risk and absorb the regulatory and financial cost when it catches up with them.

ID Wallets are a new category, the third generation of how people authenticate online. ID Wallets are like Apple Pay or Google Pay, but for identity: alongside a credit card, an ID Wallet holds a national ID, a driver's license, a passport, an employee badge, a university diploma, and other verified credentials. Sharing one of these becomes as simple as paying with your phone: in one tap, without filling up lengthy registration forms and with full control over your private information.

Gataca is the middleware infrastructure that helps companies interact with all these ID Wallets, worldwide, augmented with a trust intelligence layer.

We were founded out of MIT Sloan and operate as a Spanish company under a US parent entity, serving iGaming, Banking, Media, Governments, and Higher Education, among others.

Regulatory enforcement in this space is accelerating across the EU and North America, and the market has not yet consolidated around a clear leader. The technology is proven. The commercial function that turns it into market leadership is still being built, which is exactly why this role exists.

If you want to help build a category leader rather than execute a playbook someone else already wrote, this is that opportunity.