Private capital firms manage trillions in assets, yet their operating model remains stuck with tools not built for the purpose. Dealstack, a platform founded by former Kirkland & Ellis Partner Joel Arnell and ex-Oaktree Capital investor Seb Lapinski, aims to change that.
Today, Dealstack has closed a $5.5 million seed funding round, with participation from current and former professionals at industry-leading firms such as Paul Weiss, Kirkland & Ellis, Latham & Watkins, KKR, CVC, TA Associates, Goldman Sachs, and more. The valuation was not disclosed to TFN.
With the new capital, the company plans to expand its go-to-market and engineering teams.
How Dealstack transforms PE deal management
Dealstack was established by Joel Arnell and Sebastian Lapinski, both bringing significant experience in private equity and legal services. Arnell previously served as a partner at Kirkland & Ellis and held positions at Linklaters and Triton Partners, while Lapinski brings expertise from Oaktree Capital and private equity operations.
The founders launched Dealstack to tackle inefficiencies in private equity deal administration. Drawing from their firsthand experience with outdated manual workflows, they created tools to streamline processes, reduce errors, and save time. Rather than completely overhaul existing practices, they focused on improvements that industry professionals could readily adopt.
Seb Lapinski, co-founder and COO, said, “Private equity is full of brilliant people working with ancient tools. We built Dealstack because highly qualified professionals shouldn’t be stuck copying and pasting data from spreadsheets to PDFs when AI and automated workflows can do that for them.”
In just two years, Dealstack has gained the trust of six of the top ten global private capital firms (based on funds raised) and eight of the top ten in Europe. Currently, Dealstack’s clients manage more than $2.6 trillion in assets. Over 30 prominent private capital firms worldwide, including leading private equity sponsors and M&A law firms, rely on the platform. Dealstack aims to become as essential for private equity professionals as Word or Excel is in business environments.
Behind Dealstack: the application layer that unlocks AI and agentic workflows in private capital operations.
AI’s promise has yet to translate into real-world utility within the private capital industry. Data security concerns and issues with model hallucination and specificity present significant challenges, especially considering the industry’s stringent regulatory environment. AI applications must be flawless, as broadly trained models struggle in an industry reliant on confidential data and unique working practices. Dealstack manages numerous operational tasks, allowing investors to concentrate on their primary role — investing.
The company streamlines essential workflows—including valuation waterfalls, employee equity and ownership tracking, organisational charts, and contract management — all within a single, organised platform designed for private capital. This results in faster execution, real-time collaboration, and improved data quality, significantly saving time and cost.
Lapinski told us exclusively, “We are purpose-built for private capital. We’ve been there and done that and are building a tech solution that not only caters to the complexity of private capital workflows, but which also paves the way for AI and agentic workflow adoption across the industry. Private capital has incredibly high requirements for accuracy (where a zero too many can be an extremely expensive mistake…).
Current LLM models have been trained on public data and in an industry built on private data they struggle with recall accuracy, hallucination and gaining user trust. This has meant low levels of adoption in real life applications in private capital. Dealstack AI solves this by structuring and enriching data before it reaches LLMs who can more easily make sense of it and provide complete answers which are also validated before being served to the user. This is a unique approach built on a proprietary data model and proprietary data points.”
Customised data model, AI integration, and focus on creating reliable infrastructure
Dealstack’s private capital data model is customised for each client and underlies the AI that connects all relevant elements: individuals, entities, legal agreements, and ownership roles. It enhances clarity and consistency within private capital’s complex ownership and waterfall frameworks while strengthening legal and regulatory compliance.
Dealstack provides a comprehensive private capital ontology that maps legal, financial, and ownership relationships, offering a single, verifiable source of truth. Clean, interconnected, and trustworthy data forms the foundation for reliable AI-driven workflows in private capital — infrastructure that Dealstack is building.
“As M&A lawyers and investors, we’ve lived these inefficiencies firsthand,” added Joel Arnell, co-founder and CEO. “We built a platform specifically for private capital to automate the prevailing highly manual workflows. The broad backing from leading industry figures shows we are on the right track.”
