Exclusive: AI startup Viktor raises $75 million to put a virtual ‘coworker’ in Slack and Teams

After landing in the social media giant’s ranks, he met Peter Albert, an engineer who had worked on Meta’s Llama 2 team, and the pair spent their evenings experimenting with AI, aiming to develop agents that could eventually take over the most tedious parts of knowledge work. Several products later, that partnership has produced Viktor, an AI agent that operates like a virtual coworker embedded inside a company’s Slack or Microsoft Teams workspace.

The company has just raised a $75 million Series A, led by London-based venture capital firm Accel Partners with participation from Bek Ventures, Kaya VC, and Tenacity Capital. Angel investors, including Slack cofounders Stewart Butterfield and Cal Henderson, Synthesia CEO Victor Riparbelli, and executives from Google DeepMind, Figma, and ElevenLabs also participated in the funding round. Just three months after Viktor’s public launch in February, the company says it has reached a $15 million annualized revenue run rate and has more than 2,000 organizations using the product across sectors like e-commerce and technology.

Viktor is supposed to function just like a colleague, with team members messaging the bot to ask for help for things like pulling a report or building an internal app. It can connect to the systems the business relies on—such as Google Drive, Meta Ads, Airtable, Notion, and Shopify—and build up a persistent memory of how the organization operates. 

The company says Viktor can also scan public channels and propose new workflows it can take over. In one example, Wiatrowski said Viktor reviewed a complex Meta Ads setup and flagged a tweak that saves about $10,000 a week in advertising spending. 

Before Viktor, the founders built JaceAI, an email assistant that worked inside a user’s inbox and tried to decide what to do with each incoming message. Wiatrowski said the ideas behind Jace eventually led to Victor when the team realized that the email inbox was not the most optimal place for an AI agent. JaceAI is still operating as a separate company.

Zhenya Loginov, a partner at Accel, told Fortune the firm had met the founders several times over the past two years as they launched previous products. But while earlier tools impressed on technical grounds, they felt too niche to support a large company. 

When Viktor launched, Loginov said Accel partners flew to Warsaw within weeks.

Loginov said Accel had been looking for a team-focused assistant rather than another personal helper. “Most of these products, if not all of them, are focused on individual assistance…not for the team, and that was one of the big kind of product choices that [Viktor] made that we thought was fantastic,” he said

Betting on AI coworkers

Viktor is part of a broader wave of companies trying to build agentic AI coworkers. The startup is competing in a tough market where Microsoft, Salesforce, and other Big Tech companies are racing to build their own similar products.

Viktor runs inside Slack and Teams, for example, but Slack’s parent company already has its own Agentforce product aimed at letting companies build and deploy AI agents on top of Salesforce data and which can work inside Slack, and Microsoft has been weaving Copilot into both Teams and the broader Office suite. Those companies also have the advantage that they can bundle AI assistants into existing enterprise contracts and ship them as the default choice.

Viktor’s investors argue the market will expand to the size of the collaboration software category, with room for multiple large companies to serve different slices of the economy.

“We feel the personal work assistance is really the big third wave of AI adoption that can yield tens of billions of dollars of revenue,” Loginov said. “We feel that with something big like this happens, there are going to be many, many companies that will capture different parts of that market.”

Wiatrowski says Viktor’s specific edge is that it plugs into far more of a company’s tools and is designed from the start to work across a whole team. Customers can connect dozens of services, and Viktor can then answer questions and execute tasks that span those systems, he said.

The company has also been investing in safety and governance; for example, organizations can limit who is allowed to use sensitive integrations, and the product flags integrations that look personal, such as private email, and encourages users to keep them private by default. The team has also worked on prompt and product-level guardrails so the agent behaves carefully.

Viktor, by nature of being an AI bot, can still sometimes act in unintended ways, however. During one internal announcement about a layoff, Waitrowski said the bot reacted to the message with a skull emoji in a public channel.

Viktor offers a free tier so teams can test the product before committing to a subscription based on credit usage, which can be costly depending on usage. Some teams now spend more on Viktor than they do on a junior hire, Wiatrowski said.