In 2022, Stephen Ewan co-founded Restate with a vision to deliver durable workflow infrastructure. At the time, he had no way of knowing just how essential that kind of technology would become for orchestrating AI agent operations. The Berlin-based company originally focused on building an execution engine capable of keeping multi-step workflows stable even when faced with crashes or network disruptions—an attribute that turned out to be perfectly suited for the age of intelligent agents.

Durability takes on even greater importance when it comes to agent workflows, which tend to run for extended periods and follow paths that are inherently unpredictable, unlike conventional software. "You need to make sure you track exactly what you do to make it reproducible and have a consistent outcome," Ewan explained. The surge in AI agents has given the startup a significant boost. In recent months, Restate has signed several customer contracts worth six and seven figures, according to Ewan.

That growing momentum helped Restate raise a $20 million Series A round led by Singular, with Redpoint Ventures and Capital One Ventures also participating. The new funding will help Restate compete against Temporal, the dominant player in the durable infrastructure market. Founded in 2019, Temporal announced a $550 million Series E at a $12.55 billion valuation earlier this month. Even though Restate is a far smaller provider of this increasingly vital technology, it has already drawn notable customers, including the vibe coding platform Replit.

Rather than layering its durable execution engine on top of an external database, Restate built its own storage, replication, and redundancy layers from the ground up. According to Ewan, this architecture makes Restate exceptionally fast and lightweight. While many companies typically rely on durability engines for so-called heavy-weight workflows, Restate aims to shift that paradigm with a more efficient and cost-effective approach.

Ewan noted that beyond delivering durability for AI companies, the startup also serves Fortune 500 clients, including those in the financial sector. Although Restate can be applied to a variety of use cases, Ewan said customers all share the same fundamental need—a way to guarantee that if something goes wrong mid-process, the system can automatically recover and reassemble itself.

Before founding Restate, Ewan was a co-creator of Apache Flink, a widely used open-source stream-processing framework, and later served as CTO of Data Artisans, the company commercializing the project. Alibaba acquired Data Artisans in 2019 and rebranded it as Ververica, where Ewan remained CTO for three years. Restate's two other co-founders, Igal Shilman and Till Rohrmann, are former colleagues of Ewan's from both Data Artisans and Ververica.

The company plans to use the new capital to build out a go-to-market team, hire additional engineers, and expand its San Francisco Bay Area office to be closer to many existing and prospective customers. Even so, Ewan is adamant that Restate's capabilities will soon become indispensable to companies well beyond the traditional tech world. "If we fast-forward a couple of years, it's one of those tools, like a database, that I think pretty much any company will have a use case for, no matter their shape and size," he said.