FounderOS
AI Chief of Staff for Startup Founders
Available for new roles
Supratim
Sarkar
Software Engineer · Local-First · AI Engineering · Full-Stack TypeScript
M.Sc. Software Engineering (VU Amsterdam × UvA). AWS SAA-C03 certified. Building fast, collaborative, and intelligent systems.
About
Building at the
frontier.
The rarest thing in engineering isn't brilliance — it's someone who can take a half-formed idea from whiteboard to production without losing momentum or quality. I've shipped real-time collaborative editors, AI-powered pipelines, and accessibility tooling — independently, on time, in public. If you want someone who thinks in systems, writes code that lasts, and doesn't need hand-holding to deliver, that's the work I do.
I'm a software engineer with an M.Sc. in Software Engineering from VU Amsterdam & University of Amsterdam (Joint Degree) and an AWS Solutions Architect – Associate certification.
I interned at Mendix (Siemens), shipping production React/TypeScript to thousands of enterprise developers globally. Since then I've independently designed, built, and deployed three live full-stack products covering local-first architecture, streaming AI infrastructure, and AI-powered accessibility auditing.
I'm an open-source contributor to Tiptap (37k ★) and Infisical (27k ★), fixing bugs at the ProseMirror internals level.
- Local-first systems with Yjs CRDTs & IndexedDB
- Streaming AI pipelines using ReadableStream
- Serverless Chromium + Claude Vision for AI auditing
- Stripe billing with HMAC-verified webhooks
Open-Source Contributions
Tiptap★ 37k
- PR #7976—Fixed a logic inversion in character-count where autoTrim deleted from the document beginning instead of the end. Implemented findDocPositionAtChar() to walk the ProseMirror node tree and locate the exact character-limit boundary; added a full regression test suite.
- PR #7977—Fixed a ProseMirror console error in the Link extension by coercing undefined HTMLAttributes to null via ?? null on class, target, and rel in addAttributes().
Infisical★ 27k
- PR #7028—Fixed unreachable admin signup button on desktop caused by justify-center on a max-h-screen + overflow-y-auto flex container clipping content above the scroll origin. Replaced with my-auto on the inner wrapper.
Technical Skills
Languages
TypeScriptJavaScript (ES6+)SQLHTML5CSS3
Frontend
ReactNext.jsTiptap/ProseMirrorReduxZustandTailwind CSSShadcn UIZod
Local-First & Real-Time
Yjs (CRDTs)IndexedDBDexieBroadcastChannely-webrtcy-websocketWebSockets
Backend
Node.jsExpressREST APIsgRPCDrizzle ORMReadableStream
AI Engineering
Claude Vision APIOpenAI SDK / OpenRouterGemini APIStructured JSON generationContext & memory injection
Cloud & Infra
AWS (SAA-C03)VercelRailwayPuppeteer (serverless)PostgreSQL (Neon)InsForge (YC P26)Stripe
Testing
JestReact Testing LibraryTDD
Work
Independent
Engineering
Three live, production full-stack products — architecture, infrastructure, and deployment — full ownership.
2024
Anchor
Offline-First Notes with Conflict-Free Sync
Aria
AI Website Accessibility Auditor
Contact
Let's work
together.
I'm open to full-time roles, contract work, and interesting collaborations. If you're building something ambitious, I'd love to hear about it.