Senior Software Engineer
SR2 | Socially Responsible Recruitment | Certified B Corporation™ · London Area, United Kingdom
About this role
As a Founding Product Engineer, you will build end-to-end product features across backend, data, applied AI, and frontend. You will work closely with the founders and users to understand problems and decide what should actually be built. The technical environment involves Node.js, TypeScript, React, PostgreSQL, and modern cloud infrastructure, with a focus on building AI-powered workflows using LLMs, RAG, and agentic workflows. You will have significant influence over the architecture, engineering standards, and direction of the product in an early-stage startup environment. The role involves balancing speed and pragmatism with a high bar for engineering quality.
Skills & technologies
Nice to have
- Python
- Startup experience
Mentioned in this posting
Read full description
Founding Product Engineer | London | Hybrid | AI x Private Markets | Node.js & React
Salary: £100,000–£120,000 + equity
Location: London, hybrid working
An ambitious early-stage AI company is looking for a Founding Product Engineer to join its growing engineering team and help build a sophisticated B2B product from the ground up.
They’re tackling a complex, data-heavy industry where existing workflows are still surprisingly manual and fragmented. The opportunity for AI is significant, but the interesting engineering challenge goes far beyond simply plugging an LLM into an existing product.
You’ll be joining early enough to have significant influence over the architecture, engineering standards and direction of the product, working closely with the founders and users to understand problems and decide what should actually be built.
What you'll be doing:
- Building end-to-end product features across backend, data, applied AI, and frontend.
- Designing systems that work effectively with large amounts of complex and unstructured data.
- Building AI-powered workflows into a genuinely useful customer-facing product.
- Working directly with users to understand their problems and turn ambiguous requirements into software.
- Making architectural and technical decisions as the platform develops.
- Helping establish engineering standards, tooling and ways of working within an early team.
- Balancing speed and pragmatism with a high bar for engineering quality.
Tech stack / relevant experience:
- Backend: Node.js preferably, would consider Python
- Frontend: TypeScript, React
- Data: PostgreSQL and modern data technologies
- AI: LLMs, RAG, retrieval, agentic workflows and evaluation
- Cloud: Modern cloud infrastructure and deployment tooling
They're not looking for someone who ticks every technology box. Strong product engineering fundamentals, technical curiosity and evidence that you've taken meaningful products from idea through to production are much more important.
What they're looking for:
- Strong full-stack/product engineering experience.
- Experience owning significant features or products end-to-end.
- Comfortable working directly with users and thinking beyond the technical implementation.
- Strong product judgement and the confidence to make pragmatic decisions.
- Experience or a strong interest in building production AI products.
- Comfortable with ambiguity, changing priorities and the responsibility that comes with joining early.
- Startup or similarly high-ownership experience would be advantageous.
The calibre bar is high. They’re looking for engineers who want to be surrounded by smart, ambitious people, take on significant responsibility and help shape both the product and engineering culture as the company grows.
For the right person, this is an opportunity to get the greenfield ownership of a very early startup, meaningful equity and difficult technical problems, whilst building a product with clear commercial applications.
📩 imogen@sr2rec.co.uk
Founding Product Engineer | London | Hybrid | AI x Private Markets | Node.js & React
