S
StackOne
AI · London, United Kingdom · Founded 2023
Accelerate your SaaS growth with our unified API solution for HRIS, ATS, and CRM MoreLess
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.
Keywords: Unified API, Software Integration, HRIS, CRM, Marketing API, Klaviyo, Subscription Model, Usage-Based Pricing, Secure Integrations, Tech Startup.
Company overview
StackOne company information
The essential company record, classifications and operating signals in one place.
- Status
- Operational
- Founded
- 2023
- Headquarters
- London, United Kingdom
- Employees
- 54
- Open positions
- 5
- Dealroom signal
- 79.7
Valuation & funding
StackOne 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 | ↗ |
Financials
Workforce over time
Available workforce history. Financial fields without reported data are omitted.
| Year | Employees |
|---|---|
| 2026 | 56 |
| 2025 | 57 |
| 2024 | 33 |
Growth signals
StackOne website traffic
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.
Hiring
Open positions at StackOne
Current openings linked to this company in Dealroom.
Comparisons
StackOne compared with similar companies
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Talent graph
StackOne's talent
Source: Dealroom Talent Intelligence.
Global footprint
Where StackOne has talent and traffic
team presence
In the news
Latest news about StackOne
Recent press, funding announcements, and product moves mentioning StackOne — open to read from the original sources.
Market sentiment
What the market is saying about StackOne
An AI-synthesized read of the highest-engagement posts about StackOne on X over the past 7 days. We rank by likes & retweets, ignore corporate channels, and surface the themes that broke out from real people.
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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