CTO & Co-Founder Proptech

Antai Ventures is a Barcelona-based venture studio with presence across Southern Europe and LatAm. We partner-up and invest in the best co-founders to build global companies willing to disrupt multi-billion dollar industries. Since 2012 we have co-founded 30 companies including Glovo Wallapop PlatanoMelon and Piper. Our ventures have raised more than $1.5B in funding have generated more than $3B in shareholders value and currently employ more than 3000 people.

We are building an AI-native platform for the real estate sector in Spain one of the most fragmented relationship-driven and underdigitised industries in Southern Europe.

We have a validated product thesis a clear go-to-market and were now looking for a co-founder & CTO to build it.

• Build launch and scale a disruptive product from scratch.

• Own the technical architecture define the stack set the engineering standards and make the hard trade-offs between speed and scalability from day one.

• Design and implement a multi-agent orchestration layer persistent state management agent-to-agent handoffs tool-calling pipelines and context windows that dont collapse under real usage.

• Build and maintain LLM-powered workflows in production.

• Integrate third-party infrastructure (voice providers CRMs payment and signing APIs document verification) into a coherent maintainable system.

• Ship code daily from prototype to production you are hands-on throughout.

• Drive a culture of excellence through continuous delivery rapid experimentation and customer-obsessed iteration.

• Proven track record as a hands-on engineer tech lead or CTO in an early-stage environment.

• Hands-on builder. You prototype fast and turn ideas into working features in days not weeks.

• Practical AI experience. You have built production systems with LLMs agent orchestration multi-agent workflows conversational AI and know what actually works outside a demo.

• Architectural thinking. You design systems that are simple enough to ship fast today and solid enough to scale tomorrow.

• Ownership mindset. You take responsibility for outcomes and think long-term about product and company value.

• Clear communicator. You can explain technical trade-offs to engineers and non-technical co-founders alike.

• Fluency in Spanish and English.

• Day-1 founding seat. Join an ambitious venture from the ground up with a validated concept and Antais full backing.

• Significant equity. Own a meaningful stake in the venture plus optional carry in other Antai portfolio companies.

• Full-stack operator support. Access Antais expert teams in Product Engineering Design GTM Legal Talent and Fundraising whenever you need them.

• Founder community and investors. Join a tight network of serial entrepreneurs and top-tier backers who have scaled category leaders.

• Based in Barcelona hybrid.

Required Experience:

Founder