Senior Fullstack Engineer - Own High-Impact AI Systems

Siena AI; España; Remote; EUR 100,000 - 180,000; Full time

Benefits offered by this job

Equity or stock grants

Learning budget

Premium AI tools accounts

Job summary

Siena is seeking a senior software engineer to own meaningful parts of the platform end to end, shipping reliable, high-performance systems used by global brands. You’ll partner with product to shape scope, make architectural calls, and drive delivery with autonomy and accountability.

You’ll work on full-stack features across frontend, backend and infrastructure, tackle performance at scale, and push boundaries with enterprise-grade AI workflows.

Qualifications

• 5+ years shipping and owning systems that are live in production.
• Strong in our core stack: Node.js, React, TypeScript, Express.
• You’ve shipped LLM-powered features to real users; you know production traffic considerations.

Responsibilities

• Own features and systems across the full stack from problem definition through production.
• Partner with product to break down scope and ship iterative releases.
• Make architectural decisions and explain the reasoning to the team.

Skills

Node.js

React

TypeScript

LLM integration

Microservices

Tools

AWS (Fargate, Lambda, EC2, SQS)

PostgreSQL

Redis

CI/CD (CodePipeline/GitHub Actions)

Job description

Siena is seeking a senior software engineer to own meaningful parts of the platform end to end, shipping reliable, high-performance systems used by global brands. You’ll partner with product to shape scope, make architectural calls, and drive delivery with autonomy and accountability.

You’ll work on full-stack features across frontend, backend and infrastructure, tackle performance at scale, and push boundaries with enterprise-grade AI workflows.