Software Engineer, Full Stack

About Helios (YC W23)

Most software helps companies manage support and sales. At Helios, we're building systems that help companies run them.

We're building a new layer of AI-native operations infrastructure, systems that combine intelligent agents, orchestration, and real-time reliability to power sales and support inside real businesses. We work with banks, startups, and enterprise companies globally. Backed by Y Combinator, Accel, 1517 Fund, and Goodwater.

About the founder

Eric (CEO) previously founded on Holacasa, an end-to-end mortgage solution backed by Y Combinator, later pivoted into Helios. We started Helios because we saw how fragile current AI implementations are in real production environments, most AI agent companies break the moment volume goes from 100 to 10,000 conversations a day.

About the role

This is not a narrow role.

We're looking for someone who can move across engineering, infrastructure, and customer reality. Someone who can ship product, keep systems healthy, solve production problems, and help customers succeed on top of what we're building.

You will own:

The production runtime that powers our voice and WhatsApp agents Reliability, observability, and on-call for live customer traffic The abstractions that let us deploy new agents across customers without breaking the ones already in production

First 30 / 60 / 90 days

30 days: Ship your first production change to a live customer agent. Document the current architecture, latency budget, and failure modes. 60 days: Lead a meaningful architectural improvement to the agent runtime. Stand up an evals harness so we can ship voice changes without praying. 90 days: Own the on-call rotation for production agents. Lead the architecture for our next enterprise customer.

What we're looking for

Strong in TypeScript / Node.js — event loops, streams, async internals Comfortable with modern infrastructure Excited by building something foundational in AI Based in Mexico City (5 days a week in office)