How do you bring transparency, efficiency, and absolute trust to a €33 billion market that has been deeply underserved and analogue for decades? You look to the visionaries who have already revolutionized how we live and travel.
In this edition, we sit down with Jeroen Merchiers (former EMEA leader who helped scale Airbnb to its 2020 IPO) and Guillermo Ceballos (a seasoned entrepreneur who successfully sold his previous venture to French benefits giant Sodexo). Together, they founded Zazume—a Barcelona-born proptech powerhouse built to do for long-term residential rentals what Airbnb did for short-term stays. By combining proprietary AI-driven technology with embedded financial services, Zazume democratizes the market, guaranteeing over €50 million in rental income to small landlords while managing a staggering €735 million in residential assets.
Dive into our exclusive Q&A to discover how they achieved profitability, secured a fresh €2.5M funding round, and why they are the natural partner for financial institutions looking to unlock the massive Southern European real estate ecosystem.
1. Tell us about yourself / your co-founder(s).
I’m Jeroen Merchiers, CEO and co-founder of Zazume. Before founding Zazume, I worked at Airbnb, where I led the EMEA business all the way up to IPO in 2020. My cofounder is Guillermo Ceballos (Willy), who sold his last company to Sodexo, a french benefits powerhouse. Together we founded Zazume in Barcelona to do for residential rental management what Airbnb did for short-term stays: bring transparency, efficiency, and trust to a market that has been deeply underserved for decades.
2. Who are your target customers, and what problem / opportunity do you address for them?
We democratize the rental market by providing technology and financial solutions to small landlords that previously only were available to bid real estate funds. Our primary customers are individual landlords, who represent 94% of Spain’s rental property ownership (typically holding fewer than 3 properties). For landlords, the core problem is risk and opacity: will the tenant pay? What happens if they don’t? We address this head-on by guaranteeing rent payments to landlords — aligning our incentives completely with rigorous tenant selection.
We have 2 channels to reach our customers: directly via digital ads and inorganic as we recently started to acquire rental portfolios from real estate agencies. Spain has close to 60,000 small agencies, 96% of which have fewer than 5 employees. These agencies are focused on sales transactions where margins are higher, which means rental management is treated as a residual business: analogue, unprofitable, and under-resourced. We offer them a way to monetize their rental portfolios and add a recurring revenue stream they currently leave on the table.
3. What is your product / solution? Who do you compete with, and what is your USP?
Zazume is the only platform in Spain that digitizes the full rental lifecycle — from tenant acquisition and qualification through contract management, rent collection, maintenance coordination, and landlord reporting. Our platform combines proprietary AI-driven technology with embedded financial services, including our rent guarantee product and instant liquidity by advancing up to 3 years of your rent.
We compete with traditional property managers and a handful of proptech players. Our USP is the alignment of incentives: because we guarantee rent to landlords ourselves, we have skin in the game on tenant quality. Competitors that don’t carry that guarantee don’t have the same incentive to be rigorous. We also have the only end-to-end platform in the market, which is reflected in our Trustpilot rating of 4.5 stars across more than 1,000 reviews.
4. How do you help scale financial services, and how can financial institutions partner with you?
Zazume sits at the intersection of real estate and financial services in a meaningful way. We’ve already guaranteed over €50 million in rental income to landlords — essentially underwriting rental risk at scale across a market that moves approximately €33bn in annual rental payments in Spain.
The partnership opportunity for financial institutions is real and immediate. Insurance companies can distribute rental guarantee and non-payment insurance products through our platform and even incentivize cross-selling of their products. Banks active in mortgages for buy-to-let landlords can use our data layer — tenant quality scores, payment history, property performance — to improve underwriting. We’re also a natural distribution channel for landlord-focused financial products (insurance, financing for renovations, etc.) given our direct relationships with thousands of small landlords who are currently underserved by mainstream financial institutions.
5. What relevant industry trends or market shifts should we be watching?
Three things worth watching closely in Southern European residential rental:
- First, consolidation of the agency market is coming. The fragmentation is extreme: tens of thousands of micro-agencies with no succession plan, no digital infrastructure, and declining margins from their rental books. The conditions for roll-up are ripe, and we’re already executing on this (our first acquisition was in Zaragoza, with four more expected before year-end).
- Second, AI is finally making tenant underwriting scalable. The combination of open banking data, employment verification APIs, and ML-based effort rate modelling means that what used to take days can now happen in minutes. This changes the economics of the rental guarantee product significantly.
- Third, regulatory pressure in Spain is increasing landlord anxiety — rent caps, extended eviction timelines, political uncertainty. This actually accelerates demand for professional management and guarantees, as landlords seek to de-risk their assets. For financial institutions, this creates both insurance product opportunities and a growing pool of landlords open to new financing structures.
6. What is your current stage and traction, and how can our network help?
We’ve reached break-even and just closed a €2.5M round led by Nordstar (London) and GTV Capital, with Sabadell Venture Capital also in our cap table. The round is funding our inorganic growth strategy: acquiring rental portfolios from small agencies across Spain’s provincial capitals before looking abroad. Current traction: 3,500 properties under management, targeting 5,000+ by end of 2025 and 10,000+ by 2027. We’ve guaranteed over €50M in rents to landlords, have more than 400,000 verified tenants in our database and manage around 735M€ in residential assets.
How your network can help: introductions to financial institutions interested in insurance or financial product distribution through our platform, and to investors or family offices interested in backing the consolidation opportunity in Southern European residential rental.
7. What’s on your bookshelf or podcast app? Your favourite place for a coffee or a drink?
I start most days with a flat white on the go: it sets the pace. I mix fiction and non-fiction in my reading, and podcasts are my companion on longer bike rides. The book I’ve most recently pressed into people’s hands is The Advantage by Patrick Lencioni. I gifted it to my entire leadership team for Sant Jordi, a ancient Catalan tradition. It distils some of the most important management principles I’ve drawn on in my own career, and it’s one of those rare books that’s both practical and genuinely clarifying.
Zazume’s journey from a bold vision in Barcelona to managing thousands of properties and breaking even is a masterclass in aligning market incentives with cutting-edge fintech.
By putting “skin in the game” through their rent guarantee product, Jeroen and Guillermo aren’t just managing properties—they are fundamentally de-risking real estate assets for the everyday investor. As they embark on a rapid inorganic growth strategy to consolidate the fragmented agency market across Spain and beyond, Zazume is undeniably a company to watch.