Staff Software Engineer

Lumina Tech Group; Greater London; On-site; GBP 150,000 - 250,000; Full time

Job summary

Lumina Tech Group in London is seeking a Staff Software Engineer to design, build and scale production AI products. You will own backend development, work across full stack with Python and TypeScript, and collaborate directly with customers to solve real-world problems.

After funding, you will join an early-stage AI startup, enjoy significant ownership over product and technical direction, and help shape engineering best practices and architecture.

Qualifications

• 5–10 years of commercial software engineering experience.
• Experience building and shipping production AI products.
• Hands-on experience with AI agents or LLM applications.
• Experience working within Seed or Series A startups.
• Strong cloud infrastructure knowledge.
• Experience with Kubernetes and distributed systems.
• Customer-first mindset and experience working directly with end users.

Responsibilities

• Design, build and ship production AI products end-to-end.
• Develop scalable backend services using Python.
• Build intelligent AI agents and LLM-powered applications.
• Work across the full stack using Python and TypeScript.
• Develop cloud-native applications using Kubernetes and serverless technologies.
• Integrate with third-party APIs and CRM platforms.
• Work directly with customers to understand requirements and deliver technical solutions.
• Help shape engineering best practices and technical architecture.

Skills

Startup mindset

Ownership

Customer-facing communication

Problem solving

Build products from scratch

Tools

Kubernetes

Serverless architectures

Redis

Kafka

LangChain

LangGraph

ElevenLabs

Vapi

Retell AI

httpx

AsyncOpenAI

FastAPI

Job description

Staff Software Engineer (AI Products) | London | £150,000–£250,000 + Equity

Location: London (5 days onsite)

About the Company

Our client is an early-stage, venture-backed AI startup building next-generation AI-powered products that are transforming how businesses interact with their customers.

Following recent funding, they're looking to hire an exceptional Staff Software Engineer to play a key role in building and scaling their AI platform.

This is an opportunity to join at an early stage, work on cutting-edge AI technology and have significant ownership over product and technical direction.

The Opportunity

We're looking for an experienced software engineer with a strong backend focus who enjoys building products from the ground up.

You will be responsible for designing, developing and shipping production AI products, working across the full stack and partnering directly with customers to solve real-world problems.

This role suits someone who thrives in fast-moving startup environments and enjoys taking ownership from idea through to production.

Responsibilities

• Design, build and ship production AI products end-to-end
• Develop scalable backend services using Python
• Build intelligent AI agents and LLM-powered applications
• Work across the full stack using Python and TypeScript
• Develop cloud-native applications using Kubernetes and serverless technologies
• Integrate with third-party APIs and CRM platforms
• Work directly with customers to understand requirements and deliver technical solutions
• Help shape engineering best practices and technical architecture

About You

You'll likely have:

• 5–10 years of commercial software engineering experience
• Experience building and shipping production AI products
• Hands-on experience with AI agents or LLM applications
• Experience working within Seed or Series A startups
• Strong cloud infrastructure knowledge
• Experience with Kubernetes and distributed systems
• A customer-first mindset and experience working directly with end users

Technical Skills

• Python
• TypeScript
• FastAPI
• AsyncOpenAI
• httpx
• Cloud infrastructure
• Serverless architecture
• AI Agents
• LLM integrations
• LangGraph
• LangChain
• Voice AI platforms
• CRM integrations
• ElevenLabs
• Vapi
• Retell AI
• Redis
• Kafka

What We’re Looking For

You'll be someone who:

• Loves building products from scratch
• Enjoys solving difficult engineering problems
• Has a startup mindset
• Can balance speed with quality
• Takes ownership
• Communicates confidently with both technical and non-technical stakeholders

This Role May Not Be Right If

• Your background is primarily Machine Learning research or Data Science
• Most of your career has been spent in large enterprise organisations
• You prefer highly structured environments over fast-paced startups
• You haven’t built production AI applications