SXSW London has retained Assembly, a Stagwell (NASDAQ: STGW) agency, as its agency of record, extending the partnership following a competitive review at the end of 2025.  

The decision keeps Assembly in place to lead full funnel, performance driven media for the 2026 festival, as SXSW London moves from launch into scale. The agency was originally appointed ahead of the 2025 debut, tasked with building engagement awareness and driving ticket sales across UK and international EU audiences through integrated digital activation.  

For 2026, the remit remains focused on paid search, paid social, and display, with the addition of affiliates, but the brief has evolved. The emphasis is now on accelerating ticketing demand generation while expanding SXSW London’s global audience reach across creative and technology communities. It reflects a broader shift in how major cultural platforms are being evaluated, not just on cultural impact, but on their ability to deliver measurable growth.  

Originally founded in Austin, South by Southwest has long operated at the intersection of technology, media and culture. Its London edition is part of a wider international expansion, as the brand looks to establish a sustained presence in Europe and tap into the city’s influence as a global creative hub.  

Assembly’s reappointment signals confidence in an approach that treats brand and performance as interdependent rather than sequential. The agency’s model centres on building connected experiences that drive both demand and conversion, supported by its STAGE Experience Engine and Brand Performance Planning framework.  

The account reinforces Assembly’s positioning with clients operating at the convergence of culture, technology and entertainment – sectors where audience development, precision media and accountability are increasingly inseparable.  

ABOUT ASSEMBLY

Assembly is a global omnichannel agency built for brands that want a more modern approach to building brands that perform. Backed by the Stagwell network, we are a literal assembly of data, talent, and technology built to unlock smarter, faster, and better-performing outcomes from the bottom up -not the top down. Curious, collaborative, and driven by change, we are an agency of builders who believe the better the experience, the better the performance. We don't see brand and performance as an either/or. For us, it's always both. The +\ symbol in our logo, known as the ORAD, represents this mindset. It's a mark of how we think, how we build, and how we deliver results across the full funnel. Assembly's foundation is built on three core elements: our purpose-built STAGE Experience Engine, the strategic product it powers-Brand Performance Planning (BPP) - and an organisational design built for speed, depth, and the demands of modern marketing. Together, they enable us to build better brand experiences that reimagine how brands connect, engage, and grow across data, tech, media, creative and commerce. With over 3,000 experts in 44 offices worldwide, Assembly delivers full-funnel solutions that help the world's most ambitious brands perform. Learn more at assemblyglobal.com

ABOUT SXSW

Join SXSW London 2026. Shape the Future.

Powered by the dynamism and diversity of Shoreditch, SXSW London has become the preeminent global platform for the convergence of business, technology and creativity. Stretched across the streets of East London, the festival is unapologetically progressive and provocative.

Contemporary life moves faster and faster. SXSW London fearlessly embraces the growing landscape at the intersection of technology and culture to connect speakers, delegates and performances beyond any single industry. The SXSW London community seeks provocative debates that resonate in a global city, known for its openness to opposing voices.

In a time of uncertainty, SXSW London offers innovators and freethinkers practical optimism and a unique lens with which to navigate real world problems with clarity. Join us for a unique week of insights, networking and discovery across film, music, the visual arts, business and tech. Discover the future intelligence that upends established ideas and leave with frontier thinking for a new competitive edge.