S2 blog · Apr 2026
Introduced client-supplied encryption keys for durable streams, letting teams control key material without changing record APIs.
Company research
Public company, workplace, funding, and market signals
Overview
S2.dev (also branded Stream Store) is a San Francisco-based developer infrastructure company building a serverless API for unlimited, durable, real-time streams—an S3-like storage primitive for data in motion, with replay, tailing, access control, and self-hostable/open-source components. Public sources disagree on the founding year (company/profile sources point to 2023; YC lists 2024), so I used 2023 here.
Primary product
Serverless API for durable, real-time streams
Founded
2023
Headquarters
San Francisco, California, United States
Team size
1-10 employees
Industry
Technology, Information and Internet
Sub-industry
Streaming data infrastructure / developer tools
Offices
San Francisco, California, United States
Business model
usage-based SaaS
serverless API
managed cloud service
open-source self-hostable software
Funding
Stage
Seed
Total raised
$5.5M
Latest round
Seed · Feb 2026
Latest amount
$3.9M
People & investors
Leadership
Co-Founder and CEO
Co-Founder and CTO
Co-Founder
Founding Engineer
Infra Engineer
Work & culture
Small, engineering-heavy infrastructure startup with an open-source and docs-first posture, frequent technical blog posts, and community support via Slack/Discord.
Product & market
Pricing
Usage-based, metered serverless pricing billed by retained data, basins, streams, tokens, writes, reads, and operations; new accounts receive welcome credits.
Differentiators
- —S3-like experience for streams
- —Unlimited durable streams
- —Replayable ordered history
- —Fine-grained access control
- —Serverless/no clusters to operate
- —Object-storage-backed durability
- —Open-source self-hostable s2-lite
- —Encryption and compliance options (SOC 2, GDPR DPA, HIPAA BAA)
Technology
REST API
OpenAPI
Protobuf
TypeScript
Python
Go
Rust
CLI
Terraform
WebSockets
Server-Sent Events
Cloudflare Workers
Cloudflare R2
Prometheus
axum
SlateDB
AWS PrivateLink
S3-compatible object storage
Customers
Kernel
Trigger.dev
Competitors
Apache Kafka
Amazon Kinesis
Confluent
Redpanda
Scale & contact
Estimated revenue
approximately $289K-$5.4M
Estimated monthly visits
6.5K
Traffic estimate as of Jun 2026
Latest news
S2 blog · Mar 2026
A product/use-case post showing a full video conferencing app built on S2 streams, including live media reads, replay, retention controls, and durable frame history.
S2 blog · Feb 2026
S2 announced general availability of the cloud service and a $3.85M seed round led by Accel, bringing total capital raised to $5.5M; the post also names customers such as Kernel and Trigger.dev.
Economic Times · Feb 2026
External coverage of the seed round, noting participation from Uncorrelated Ventures and others and stating the company had raised $5.5M total.
S2 blog · Jul 2025
Explains why AI agent sessions need their own durable streams for memory, auditability, isolation, branching, and reliable resume.
Jobs and careers at s2.dev
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