Staff Software Engineer | Async Python / TypeScript / AI Voice Agents | Must Have Startup Exp

Staff Software Engineer | Async Python / TypeScript / AI Voice Agents | Must Have Startup Experience

Location: London (5 days per week onsite - Non-Negotiable) - Office first team

Package: £120,000 - £200,000 + equity + cash

Start: ASAP (UK notice periods considered)

Eligibility: This role requires working onsite in London five days a week. Visa transfers may be available for the right candidate, and experience with async Python in a production environment is a must.

🚨 Please only apply if you have commercial experience with ALL of the following 🚨

• Strong async Python in production (coroutines, httpx, async error handling)
• Full-stack delivery across Python and TypeScript
• Building and shipping AI agents / LLM-powered products end-to-end
• Early-stage startup experience (Series A or earlier)
• Comfortable owning scope directly with non-technical customers
• Able to work 5 days per week onsite in London

Join a fast-scaling AI company in the heart of the City, Fresh off a multi-million-pound Series A, building autonomous AI voice agents that are transforming how real-world service businesses operate. This is a founding-level engineering seat where you'll own product end-to-end, ship fast, and directly shape how customers use AI to run their operations.

You'll be one of the key builders taking these systems from prototype to production, working shoulder-to-shoulder with the founders in a high-ownership, office-first team that moves at serious pace.

Required Background

• 5-10 years full-stack software engineering (backend-leaning)
• Proven experience building and shipping AI products end-to-end
• Hands-on with agentic systems (not general ML or data science)
• Production-grade async Python (AsyncOpenAI, httpx, robust error handling)
• Modern cloud infrastructure (Kubernetes, serverless, distributed systems)

ℹ️ Very Important Notes

• This is a hands-on build role - not suited to non-coders or purely managerial profiles
• You must be comfortable working directly with non-technical customers to scope and deliver
• Office-first culture - 5 days per week in London, no exceptions
• High autonomy expected - you'll design, build, ship, and iterate fast

Must-Haves

• Strong async Python and full-stack proficiency (Python / TypeScript)
• Real hands-on experience building agentic AI systems
• Ability to scope and deliver solutions with non-technical stakeholders
• Startup mindset with clear evidence of high ownership and delivery

Bonus Experience

• Voice AI or event-driven systems
• CRM integrations
• Previous founding engineer or early startup hire
• CS degree

What You'll Be Doing

Build & Ship

• Build core product features across the full stack (Python, TypeScript, cloud infra, event-driven systems, integrations)
• Take features from MVP to scalable production systems

Customer Ownership

• Work directly with customers to understand needs, scope solutions, and deliver outcomes
• Translate real-world workflows into technical direction

Raise the Bar

• Champion best practices across testing, documentation, reliability, and security
• Help level up the wider engineering team

What They're Looking For

• A builder at heart who thrives on autonomy and ownership
• Someone who knows when to hack an MVP and when to invest in scalable foundations
• An engineer energised by fast-paced, office-first startup life
• Someone who combines deep technical execution with real customer insight

If you're a builder who wants to ship production AI at pace and help define a category, get in touch for a fast response.