S
StackOne
Accelerate your SaaS growth with our unified API solution for HRIS, ATS, and CRM
About StackOne
StackOne is a dynamic startup that specializes in providing a unified API (Application Programming Interface) platform designed to simplify and streamline the integration process for businesses. The company operates in the technology and software market, focusing on clients who need to connect various software tools and systems seamlessly. These clients typically include businesses that use multiple software solutions for HR (Human Resources), CRM (Customer Relationship Management), and marketing, among others.
StackOne's business model revolves around offering a single, unified API that allows businesses to integrate different software tools without the usual complexities and security concerns. This unified API supports a wide range of integrations, including popular tools like HaileyHR, BreatheHR, HR Cloud, Pipedrive, and Greenhouse. Recently, they have also introduced a marketing API with initial support for Klaviyo, a marketing automation platform.
The company makes money by charging businesses for access to its API platform. This can be through subscription models, where clients pay a recurring fee to use the service, or through usage-based pricing, where clients are charged based on the number of API calls or the volume of data processed. By providing a reliable and secure integration solution, StackOne helps businesses save time and resources, allowing them to focus on their core activities.
In summary, StackOne is a tech startup that offers a unified API platform to simplify software integrations for businesses, particularly in HR, CRM, and marketing. It operates on a subscription or usage-based revenue model, ensuring secure and efficient connections between various software tools.
Source: Dealroom company dataAt a glance
- Status
- Operational
- Founded
- 2023
- Headquarters
- London, United Kingdom
- Employees
- 54
- Open positions
- 5
- Dealroom signal
- 79.7/100
- Industry
- Enterprise Software
- Sector
- AI, Developer Tools, API, Core AI, B2B Integrations, MLops, AI Model Deployment and Monitoring, AI Agents, uk is8 digital and technologies
- Technology
- Artificial Intelligence
- Business model
- SaaS
- Client focus
- b2b
Knowledge graph
More headlines
Funding history
Company financing events and reported valuations.
| Deal type | Date | Amount | Valuation | Investors | Source |
|---|---|---|---|---|---|
| SERIES A✓Equity / VC | May 2025 | $20M | $80M | Playfair Capital · Workday Ventures · GV · Episode 1 Ventures | ↗ |
| SEED✓Equity / VC | Mar 2024 | $3.6M | $14M | Playfair Capital · Sequoia · Charlie Songhurst · Portfolio Ventures | ↗ |
Growth signals
Latest recorded traffic for StackOne is 34K monthly website visits, up 41.7% over the last three months. StackOne's team declined 5.3% over the past year.
Similar companies
Company identity and context are open; selected comparison metrics preview what is available on the platform.
Investments and acquisitions
Recent portfolio relationships for companies that also act as investors or acquirers.
Investors
From Dealroom's funding and investor records, grouped by the round each investor first entered.
Seed5 investors entered at this stage
Episode 1 Ventures
Playfair Capital
Sequoia
Charlie Songhurst
Portfolio Ventures
Series A3 investors entered at this stage
GV
Workday Ventures
XTX Ventures
Other known investors7 additional known investors
Edward Lando
Grow London
Neil Andrew
Oliver Molander
Richard Hadler- RLRockman Law
Timoteo Rouchon
Source: Dealroom Talent Intelligence.
Global footprint
team presence
Market sentiment
An AI-synthesised read of the highest-engagement posts about StackOne on X, ranked by likes and reposts, corporate channels excluded.
Reading the room on X — pulling top posts and synthesizing themes…
Source: X recent search ranked by engagement (likes + retweets) · Synthesis by Claude · Cached for 1 hour
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