Backend development: real-time systems, multi-tenant APIs and integrations
I build backends for products that have to stay correct under real use: real-time WebSocket systems, multi-tenant APIs that isolate each customer at the database layer, and the auth, payment and third-party integrations around them. I’m Bekretsion Seyoum, a backend software engineer in Addis Ababa, Ethiopia, open to remote work.
- CRDT
- real-time sync in Collab API
- RLS
- tenant isolation enforced in PostgreSQL
- 85+
- ordered migrations run on startup in Hello
What I build
- Real-time systems: WebSocket servers with CRDT sync (Yjs), so concurrent edits merge without conflicts, scaled across instances with Redis.
- Multi-tenant APIs: a PostgreSQL schema per tenant with row-level security, scoped JWT auth and role-based access.
- Payments and billing: Stripe webhooks with signature verification, usage metered by the minute, and automatic top-ups.
- Integrations: ElevenLabs, Vapi, Google Calendar, Microsoft Graph, Dropbox Sign, HubSpot, Slack and OAuth 2.0 sign-in.
How I work
- Rules that must hold are enforced in the database — schemas, constraints, idempotency keys — not only in application code.
- Webhooks are verified, retried, and safe to receive twice.
- Scheduled jobs are idempotent, and migrations run in order on every start.
- Failures are queued and replayed instead of dropped.
Stack
TypeScript, JavaScript and SQL on Node.js and Express, with Prisma. PostgreSQL, MySQL and Redis. Docker and GitHub Actions, deployed on Render, Vercel, Neon and Upstash.
Questions
What backend work do you take on?
APIs, real-time features, multi-tenant SaaS backends, payment and billing flows, and integrations with third-party services.
Which languages and databases do you use?
TypeScript and JavaScript on Node.js, with PostgreSQL, MySQL and Redis.
Do you work remotely?
Yes. I’m based in Addis Ababa, Ethiopia, and work remotely with teams anywhere.
How do we start?
Email me at bekretsionseyoum4@gmail.com with what you’re building and where it’s stuck.