Senior Product Engineer (Python / Go) | Production Agentic AI | B2C Start-up, Series A | £100k-£200k + Equity | London (5 Days) | Visa Sponsorship + Relocation

Senior Product Engineer (Python / Go) | Production Agentic AI | B2C Start-up, Series A | £100k-£200k + Equity | London (5 Days) | Visa Sponsorship + Relocation

The Opportunity

We're working with a well-funded, high-growth technology start-up, with global presence, that's making a significant investment into its engineering team in London.

They're looking for exceptional Product Engineers with strong backend experience who want to work on technically challenging problems at the intersection of Software engineering, Product ownership and AI.

The business is already generating revenue, has an established product in production and is now entering an exciting period of growth.

This is an opportunity to join a small, ambitious engineering team, take genuine ownership of what you're building and have a direct impact on the direction of the product.

Why is this exciting? | Senior Product Engineer (Python / Go) | Production Agentic AI | B2C Start-up, Series A | £100k-£200k + Equity | London (5 Days) | Visa Sponsorship + Relocation

• £100k–£200k + Equity – Highly competitive compensation with meaningful long-term upside. Exceptional benefits too.
• Production AI – Work on real-world AI systems, not experimental proof-of-concepts or another basic LLM wrapper.
• Technical ownership – Make important architectural decisions and take responsibility for features from idea through to production.
• Strong engineering culture – Work alongside experienced engineers who care about building excellent products and solving difficult problems.
• Early-stage opportunity – Join while the engineering team is still relatively small, with significant room for personal and technical growth.
• Career progression – Opportunity to grow into Staff, Principal or Engineering Leadership positions as the business scales.

The Role | Senior Product Engineer (Python / Go) | Production Agentic AI | B2C Start-up, Series A | £100k-£200k + Equity | London (5 Days) | Visa Sponsorship + Relocation

We're looking for strong, product-minded Backend Engineers who enjoy building reliable, scalable systems and solving complex engineering challenges.

You'll have significant autonomy, working across backend architecture, AI infrastructure and product development.

This isn't a role where you'll simply be handed tickets to complete. You'll be expected to understand the problems you're solving, challenge assumptions and take ownership of delivering the right solutions.

What you'll be working on | Senior Product Engineer (Python / Go) | Production Agentic AI | B2C Start-up, Series A | £100k-£200k + Equity | London (5 Days) | Visa Sponsorship + Relocation

• Designing, building and scaling backend services using Python + Go.
• Developing production-grade AI applications, agent workflows and LLM integrations.
• Building and improving APIs, asynchronous processing systems and data pipelines.
• Working on agent orchestration, retrieval systems and AI infrastructure.
• Improving reliability, performance and scalability across cloud-native systems.
• Taking ownership of features from initial design through to production.
• Collaborating closely with engineers, product teams and other stakeholders.

What We're Looking For | Senior Product Engineer (Python / Go) | Production Agentic AI | B2C Start-up, Series A | £100k-£200k + Equity | London (5 Days) | Visa Sponsorship + Relocation

• 3+ years of commercial software engineering experience.
• Strong backend engineering experience with Python, ideally Django, or Go with a willingness to work extensively in Python.
• Hands-on experience building and deploying LLM-powered applications or agentic AI systems into production.
• Strong engineering fundamentals across APIs, SQL, system design and performance.
• Experience working in a start-up or fast-paced product engineering environment.
• A genuine product engineering mindset, with the ability to understand business problems and translate them into technical solutions.
• Excellent communication skills, strong ownership and a proactive approach to problem-solving.

Nice to have: Go, Django, GCP, Terraform, Celery, RAG, multi-agent systems and LLM evaluation frameworks.

What's On Offer? | Senior Product Engineer (Python / Go) | Production Agentic AI | B2C Start-up, Series A | £100k-£200k + Equity | London (5 Days) | Visa Sponsorship + Relocation

• £100,000–£200,000 base salary + meaningful equity.
• Opportunity to join a well-funded technology start-up at an exciting stage of growth.
• Significant technical ownership and influence over architecture.
• Work on sophisticated AI systems operating in production.
• Clear progression opportunities as the engineering team expands.
• Comprehensive benefits and professional development support.
• Visa sponsorship and relocation support available.
• London-based engineering team, working predominantly in person.

Interested? | Senior Product Engineer (Python / Go) | Production Agentic AI | B2C Start-up, Series A | £100k-£200k + Equity | London (5 Days) | Visa Sponsorship + Relocation

If you're an experienced Backend / Product Engineer with strong Python or Go experience, who's been building real AI products and wants to work on something ambitious, I'd love to hear from you.

Apply here with a Product Engineering focused CV - we want to see your ownership, metrics/impact on end-to-end agentic AI Products, and understand how successful they have been!

We will get back to you if this is a good fit for the client. :)