StackOne, a London-based AI agents startup, has secured a $20 million Series A funding round led by Google Ventures (GV), with participation from prominent investors including Workday Ventures, XTX Ventures, Episode 1, and Playfair. Notably, angel investors from OpenAI, Google DeepMind, and Microsoft also backed the round, signaling strong confidence in StackOne’s vision and technology.
Founded by former Google employees Romain Sestier (CEO) and Guillaume Lebedel (CTO), StackOne is making waves in the fast-evolving AI agents landscape. The company focuses on enterprise integration — a critical but complex sector valued in the billions — helping businesses harmonize the many digital tools they rely on daily, from communication platforms to HR systems and supply chain software.
Tackling the Enterprise Integration Challenge with AI
AI agents, powered by large language models (LLMs), are transforming business operations by autonomously completing tasks without constant human intervention. StackOne has taken this concept a step further, developing intelligent agents that can seamlessly connect and synchronize disparate parts of a company’s tech stack.
This innovation significantly reduces the time and cost of adopting new software applications. “We have felt the acute pain of integrations,” says Sestier, recalling his time at Google. “We saw teams burn months rebuilding or refusing requests, and nothing on the market eased this pain. We believe AI agents are the missing piece in finally delivering enterprise-grade integrations at scale.”
With their AI-powered platform, StackOne promises to accelerate and simplify how businesses integrate software, offering a scalable solution to one of enterprise IT’s most persistent bottlenecks.
The investment comes during a booming period for AI agents startups. According to Sifted, European AI agents startups raised €481 million in just the first six weeks of 2025 — over a quarter of the total raised throughout 2024. This surge highlights the growing investor appetite for solutions that harness AI to automate and optimize business functions.
GV’s Luna Schmid emphasized StackOne’s distinctive approach. “Romain and Guillaume aren’t building just another SaaS integration platform. They’re creating infrastructure that modern software and the entire AI agent ecosystem can rely on,” she said.
Workday Ventures and XTX Ventures also joined the round, underlining the strategic importance of StackOne’s technology in enterprise software and financial services. Returning investors Episode 1 and Playfair demonstrated continued faith in the company’s growth by participating again.
Building Infrastructure for the AI Agent Ecosystem
StackOne’s platform is more than just a tool for integration — it’s being positioned as a foundational layer for future AI agent ecosystems. As more businesses adopt AI-driven workflows, the need for smart, reliable infrastructure that can connect various systems becomes critical. StackOne aims to be at the heart of that transformation.
By addressing the technical challenges that come with scaling and integrating AI across enterprise environments, the company is building a future where AI agents can operate efficiently across complex digital landscapes.
With fresh funding in hand, StackOne plans to scale its operations, expand its team, and further develop its AI integration engine. The company’s roadmap includes deeper partnerships with enterprise software vendors, enhanced automation features, and expanding its market footprint across Europe and North America.
StackOne’s vision reflects a broader trend in enterprise technology: shifting away from siloed software solutions toward intelligent, integrated systems powered by AI. As businesses look to unlock productivity and adapt to the future of work, AI agents startups like StackOne are poised to lead the way.
