Software Engineer

Location: San Francisco, CA (On-site)

Salary: £150,000 - $220,000 + 0.10% - 0.30% Equity

Industry: AI / Fintech

Who You'll Join

A YC-backed, Series A AI startup building agentic infrastructure for Fortune 500 banks and insurers. AI agents handle over one million live voice interactions daily, end-to-end, for some of the largest financial institutions in the world. At 12x year-on-year growth and approaching $10M in revenue with around 20 people, there is real work to do and very little process in the way.

What You'll Do

1. Build and own backend systems, APIs, and voice infrastructure from design to production.
2. Ship code daily to Fortune 500 banking and insurance clients.
3. Work directly on telephony systems and real-time voice processing pipelines.
4. Integrate with legacy financial infrastructure at enterprise scale.
5. Own a specific area, such as voice AI orchestration, performance, security, or product engineering.
6. Refactor and scale systems handling over one million daily transactions.
7. Operate within SOC 2, PCI, TCPA, and CFPB compliance requirements.

Who You Are

1. Bring 3 or more years of software engineering experience with strong backend fundamentals.
2. Have worked at a Series A-stage startup through a period of rapid growth.
3. Own features completely, from initial design through to production deployment.
4. Write clean, production-ready Python or TypeScript without needing close oversight.
5. Refactored legacy systems into scalable architectures before, and enjoyed it.
6. Spend 95% of your time writing code, and want to keep it that way.
7. Bonus: Have built with telephony protocols such as SIP, WebRTC, or SRTP in production.

Tech Stack

Python, TypeScript, PostgreSQL, Kafka, Redis, ClickHouse, Kubernetes, AWS (SQS, containerized deployments), WebRTC, SIP, SRTP, LiveKit, Telnyx, Twilio

Why You'll Thrive

1. Earn $150,000 to $220,000 plus 0.10% to 0.30% equity at a company growing 12x year-on-year.
2. Join a team of six engineers where your work ships directly to Fortune 500 clients.
3. Solve hard, low-level infrastructure problems without layers of process slowing you down.
4. Work on real-time voice AI at a scale very few early-stage companies have reached.
5. Get in early at a post-Series A company with strong revenue and clear upward trajectory.