s2.dev

Unlimited, durable, real-time streams

Fall 2025

Active

Unlimited, durable, real-time streams

S2 is a serverless datastore for real-time, streaming data. The more we worked on data systems, the more we felt like there was a missing building block. The seamless experience of object storage simply did not exist for durable streams – so we set out to fix that! S2 reimagines streams as an unlimited and access-controlled web resource. Like if Kafka and S3 had a baby. - Building agents? Use granular streams to persist context in real time, make workflows auditable, and coordinate between agents. - Publishing fast-moving data? Streams support high fanout and can be accessed directly over the internet, so they are a great fit for broadcasting real-time feeds. - Sandboxing? Emit to per-instance streams, and read history or live events just as easily. - Local-first and multiplayer experiences? Propagate updates reliably and efficiently. Stop dealing with clusters, and start streaming.

Active Founders

Shikhar Bhushan

Co-founder and CEO

Making streams plentiful and serverless. Hacked on retrieval systems at Etsy, a KV store at Facebook, and Kafka Connect at Confluent.

Shikhar Bhushan

Co-founder and CEO

Making streams plentiful and serverless. Hacked on retrieval systems at Etsy, a KV store at Facebook, and Kafka Connect at Confluent.

Stephen Balogh

Co-founder and CTO

Loves Rust, and building systems that scale. Previously built novel infra for multi-modal product search at Etsy, and digital repository software at NYU

Stephen Balogh

Co-founder and CTO

Loves Rust, and building systems that scale. Previously built novel infra for multi-modal product search at Etsy, and digital repository software at NYU

Dwarak Govind Parthiban

Co-founder

Passionate about systems and AI. Worked on applied AI at Etsy, ML platform at Freshworks. Researched on language models at uOttawa and published at AAAI-21.

Dwarak Govind Parthiban

Co-founder

Passionate about systems and AI. Worked on applied AI at Etsy, ML platform at Freshworks. Researched on language models at uOttawa and published at AAAI-21.

Company Launches

s2.dev: Streams as a cloud storage primitive

See original launch post

Hi everyone! We are Shikhar, Stephen, and Dwarak, the co-founders of s2.dev. S2 is the S3 for streams.

https://www.youtube.com/watch?v=8-mUPf4P_8g

Many of the most important features in products we love are powered by streaming data, from frontend UIs that go brrr with real-time updates, to backends that store and process massive event flows. But building these sorts of real-time systems is really hard.

We are turning streams into a cloud storage primitive – just like object storage did for static files.

S2 is a completely serverless datastore, offering unlimited streams and configurable (even bottomless) data retention. Streams can be appended to and followed in real-time, and since all writes are durable, you can also read from anywhere in a stream’s history, indexed by sequence number or timestamp.

We basically took the core abstraction of Kafka – the log – gave it a URI, and brought it online with a dead simple API. And none of the bloat. 😀

https://www.youtube.com/watch?v=2a1OdJ9l78A

Why we’re building S2

We built large-scale ML infra at Etsy and Meta, and always felt the lack of a system like S2. Serverless infra for data at rest has been seamless for a long time (S3 launched 20 years ago!) – but the ecosystem around streaming data, in comparison, felt stuck in the stone age.

When we first introduced S2, we thought it would be most attractive to people already using streaming platforms like Kafka – but we’ve found that it resonates much more with builders in areas where these systems are entirely absent, who end up cobbling together general-purpose stores like Postgres and Redis and run into their limits.

We stand out on dimensions that are completely off the map for legacy systems: like the ability to have an unlimited number of streams backed by object storage, and to make them directly accessible over REST. This means S2 streams can be used as a serverless, reliable alternative to custom WebSocket or SSE infra.

S2 radically simplifies streaming

If you are dealing with a high-cardinality of data sources – for example, code execution sandboxes or IoT devices – S2 is for you. Streams can be instantly created on-demand. You don’t have to buffer or batch, just pipe into S2.

https://www.youtube.com/watch?v=wsFiwxv_RY0

We recently supercharged read scalability to handle massive fanouts. You can broadcast a real-time feed with S2 such as market data without building any infra – publishing is just a matter of POST-ing to a stream’s URL.

If you are building agents, a common pain is syncing progress between the backend and frontend, while also being able to replay history. A lot of these agent state management challenges become simple with S2.

Try it out

We should talk if s2.dev resonates with you! You can sign-up and follow the quickstart to start streaming in seconds with free credits.

There is a lot more we are cooking, including an ⭐ open source self-hostable S2 https://github.com/s2-streamstore/s2 ⭐

Talk to us

email: founders@s2.dev

discord: https://discord.gg/JfTWJ5xxZ6

twitter: https://x.com/s2_streamstore

bluesky: https://bsky.app/profile/s2.dev

YC Photos