Lovable acquires Sutro, maker of the SLang programming language

Lovable announced on September 18, 2026 that it has acquired Sutro, the company behind the SLang programming language and a platform for generating production-ready backends. Sutro founder Tomas Halgas and three Sutro engineers are joining Lovable, and Halgas will lead the company’s technical evangelism.

Sutro’s Founder and Engineers Join Lovable

In the announcement, Lovable said the Sutro team spent five years building a language, compiler, and backend platform that made application behavior and rules explicit, describing it as engineering built for security and reliability. Lovable said the deal reflects a conviction the two teams share: that people should be able to trust the software they build to run their businesses, while the platform carries more of the underlying complexity.

Lovable wrote that as more people build and ship software, “understanding it has to be as effortless as building it,” and that once anyone can put software into production, its reliability and trust have to match the experience of building it.

Halgas is joined at Lovable by Sutro engineers Max Gfeller, Tony Zhan, and Hirad Arshadi. According to the announcement, Halgas’s new role continues the work that drove Sutro: “making how the technology actually works understandable to the people building with it.”

What Sutro Built

Sutro’s website markets its product as proper backends built on what the company calls a zero-infra approach, centered on SLang, a language the site describes as concisely defining and deploying production-grade backends. The site also states that the team has more than 20 years of combined experience on code-generation engines.

Sutro’s SLang documentation describes the language’s purpose as defining entire backends, including entities, logic, and security, without boilerplate or complex syntax, in a form designed to be intuitive for humans and AI alike. The documentation lays out six core constructs: entities, persisted database records and relationships; schemas, reusable non-persisted structured types; actions, typed business logic functions; triggers covering HTTP endpoints, queues, cron jobs, and events; security spanning subjects, identity fields, groups, roles, and permissions; and modules that provide built-in capabilities such as AI and HTTP calls.

On the platform side, Sutro’s API documentation states that the service supports the generation, hosting, and editing of production-ready backends. A backend can be constructed from a single prompt processed by Sutro’s AI agent, or assembled manually through calls to the API. The result is an API server with a downloadable OpenAPI document; once published, the API is reachable at an address of the form {applicationId}.app.withsutro.com. A worked example in the documentation shows a short prompt requesting a to-do tracking service producing an OpenAPI specification with user and to-do records and operations to create, retrieve, update, and delete them.

The company’s wider documentation set covers Sutro Studio for creating and editing backends, a command-line interface for creating, previewing, validating, and publishing SLang backends, and a web console for managing projects, applications, and resources. It also documents member and builder authentication based on JSON Web Tokens and mutual TLS, and explains how Sutro-generated apps resolve authenticated subjects and evaluate SLang auth rules. Sutro offered three generation paths — prompt-to-backend, prompt-to-full-stack, and Figma-to-code — and distributed an official SLang skill for AI coding agents such as Claude Code through its SutroOrg GitHub repository, giving agents knowledge of the language’s syntax and semantics.

On its website, Sutro stated that SLang uses 12 times less code than competitors, that using Sutro is 97% cheaper than using Supabase, and that complete backends can be generated in under two minutes.

Lovable’s Recent Funding and Product Moves

The acquisition follows Lovable’s August 12, 2026 announcement that it had raised $400 million in Series C funding at a $13.3 billion valuation. Menlo Ventures led that round, which was co-led by the Scaleup Europe Fund managed by EQT; returning investors included Accel, CapitalG, and Salesforce Ventures. In the same post, Lovable said apps built on its platform see over 900 million visits every month, and said it planned to grow to roughly 450 team members in 2026, hiring most heavily in machine learning, product, infrastructure, and security roles while keeping its center of gravity in Stockholm and expanding in London, Boston, San Francisco, and New York.

On September 15, 2026, Lovable announced a partnership with Salesforce that connects apps built with Lovable to Salesforce in four ways: through Headless 360, which exposes Salesforce capabilities through APIs and MCP servers; by mentioning @Lovable in Slack channels to have apps built from a conversation; through shared Slack code channels where several people shape one build; and through agents that teams can install into Slack workspaces as bots. Lovable said all four were available at the time of the announcement, and said in the same post that people have created more than 70 million projects with Lovable since November 2024.

The Sutro deal also follows Lovable’s earlier acquisition of Molnett, which Lovable’s blog index dates to November 25, 2025, and which expanded the company’s platform team.