About a decade ago, Paul Butler and Taylor Baldwin met in the generative art world, talking about pen plotters. At the time, Butler was an analyst at Two Sigma and Baldwin a software engineer at BuzzFeed—both had spent years knee-deep in the complexities of data infrastructure.Specifically, Butler recalled a problem he kept running into while building internal tools at Two Sigma: “I realized that there was this collision course between people wanting software to run in the browser and browsers themselves not being a super high-performance compute environment.”Feeling the friction between browser limitations and compute-heavy needs, Butler said that’s when he started brainstorming solutions: “What if we sort of had this server-side process that was more capable, more compute-intensive—that the browser could just have a low-latency, real connection to?”Fast-forward to 2021, and Butler, CEO, and Baldwin, CTO, had founded Jamsocket, what they call “the most powerful solution for real-time collaboration, AI agents, and data-intensive apps,” aka, a new infrastructure primitive that brings session-scoped compute to modern applications.The Missing Space in the Modern Web StackBut the disconnect between browser limitations and compute-heavy needs wasn’t the only architectural challenge Butler noticed. The traditional web stack itself has fundamental limitations, particularly for applications that require persistent state, real-time updates or high-performance compute.As Butler described it, the traditional load balancer and stateless server model was built for more short-lived requests — not long-lived sessions or large in-memory state.“If you want to load 10 gigabytes of data into a server process—they’re just not really built for that, so you end up using the load balancer as a compute scheduler, which it’s not meant to do,” he said. “It’s meant to load-balance across instantaneous requests — not the kind of long-lived request that a stateless application requires.”Or “session-lived,” as Butler called it, “which is [when] you want state to stick around on the server … about as long as the browser tab is open — and then away when the browser tab is closed.”This is where Butler and Baldwin saw a missing space between ephemeral compute and permanent storage — and where they saw an opportunity. With the typical workaround requiring teams to serialize data in and out of Redis or a database, the pair thought: What if we replaced the load balancer with a scheduler?Building the Backend for Real-time StateWhen they set out to build Jamsocket, Butler said, they took a lot of inspiration from Figma — and it shows. In fact, the startup describes itself as “the platform for scaling sync engines, based on the infra behind Figma and Google Docs.”How does it work?Suppose two colleagues are simultaneously collaborating on a document. That means they’re both connected to a single Jamsocket session — a session that will live only as long as one person keeps the tab open. Then, it disappears.This architecture lands right in that “session-lived” sweet spot — not ephemeral, not permanent — and the ideal primitive for collaborative apps.Take Rayon, a collaborative floor-planning app, and just one example of a customer that can benefit from Jamsocket’s stateful, session-scoped infrastructure. As Butler described it, with Jamsocket, Rayon no longer needs to rely on Redis to synchronize data with the server; instead, it can use a single Jamsocket session to ensure all parties can talk to the same backend. Meanwhile, that same session can also write authoritatively to Amazon Simple Storage Service (S3).In addition to collaborative use cases like Rayon, Butler says Jamsocket supports two other primary use cases: compute-intensive applications and AI/sandboxed compute, the latter of which is quickly gaining traction as developers look for more isolated ways to run custom models.Shifting the Developer MindsetStill, despite its technical elegance, Butler acknowledged that Jamsocket can sometimes be a tough sell.As is often the case with new computing paradigms that buck conventions, Jamsocket requires developers to shift their mindset—and Butler said he wasn’t ready for it: “One of the things we’ve learned is that a lot of developers want something they can plug their code into…and [they] don’t want to deal with Docker … Coming from more of an infrastructure world, it was a surprise to us that a lot of application developers sort of think Docker is not their territory.”But Butler was also quick to affirm that Jamsocket can still meet developers where they are.For example, he spoke to the simplicity of the interface and the fact that it’s language agnostic, a pointed design decision to accommodate the workflows people already have: “[We] built it around containers in a very similar interface to something like Google Cloud Run or Roku Render—the main difference being, instead of running several of these containers behind a load balancer, we also give developers an API to spin up an individual-named instance of that process.”To further smooth adoption (and please developers), the decision was made early on to open source Jamsocket. In fact, Butler divulged that this was the very reason some early customers had the courage to get on board: “They told us, straight-up, the reason they’re able to trust Jamsocket as a business was that they knew that if anything did happen to us, they could go and run on the open source.”A prescient thought from those early customers, as something is indeed happening to Jamsocket — but the startup is far from going belly up.A New Chapter with ModalThis week, Jamsocket will be joining Modal, a next-gen infrastructure platform known for its container orchestration and AI workload support.Long familiar with the Modal team thanks to the New York tech scene and infrastructure world, Butler said the move to join Modal made a lot of sense, both culturally and strategically.“Modal has invested a lot into scaling up,” he said. “And what was really important for us when looking at an acquirer was somewhere … we thought the customers would be even better off.”With the move, Jamsocket’s broader product suite is expanding, including:Plane, the open source orchestrator that powers Jamsocket.Y-Sweet, a document store and real-time sync backend that runs on top of Jamsocket.Forever VM, stateful Python REPLs as a service for AI code execution.As Jamsocket migrates its functionality on top of the Modal container platform, customers can expect the same reliability and developer experience they know — with better observability, faster cold start times, improved performance and a more scalable foundation for the future.The post Jamsocket’s Session-Lived Infra Gets a New Home with Modal appeared first on The New Stack.