FC
Menu
ruuaen

Sophie Walsh

Freelancer

Backend Developer (Node.js / PostgreSQL)

Warsaw, Poland

Backend Developer (Node.js / PostgreSQL)

I've built backend systems for 7 years, mostly Node.js with PostgreSQL, for small teams that need a system that won't need a rewrite after the first real growth spurt. I design schemas with normalization where it matters, write reversible migrations, and set up authentication and background jobs without over-engineering for a scale that isn't there yet. I don't build frontend interfaces beyond simple admin panels — for a real client-facing UI I recommend a frontend developer. Before quoting, I ask for a spec or a short call so pricing isn't a guess.

Backend Developer (Node.js / PostgreSQL)

Skills

Node.jsPostgreSQLExpressNest.jsREST APIDatabase designAuthenticationQuery optimization

Portfolio

Booking service API — Backend

Backend — REST API for a booking service with overlap-checked scheduling endpoints.

CRM database schema — Database

Database — Designed a normalized schema for an internal CRM with indexes for frequent filters.

Reporting module optimization — Database optimization

Database optimization — Sped up slow aggregate queries using materialized views and composite indexes.

Multi-tenant SaaS backend — Backend

Backend — Backend architecture supporting multiple isolated client workspaces on one codebase.

Webhook processing service — Backend

Backend — A queue-backed service processing third-party webhooks reliably under load.

Booking service API — REST API for a booking service with

Backend — REST API for a booking service with overlap-checked scheduling endpoints. A second, similar engagement for a different client.

CRM database schema — Designed a normalized schema for an internal

Database — Designed a normalized schema for an internal CRM with indexes for frequent filters. A second, similar engagement for a different client.

Reporting module optimization — Sped up slow aggregate queries using

Database optimization — Sped up slow aggregate queries using materialized views and composite indexes. A second, similar engagement for a different client.