Founding Backend Engineer

Cavendish Professionals; Greater London; On-site; GBP 110,000 - 170,000; Full time

Job summary

Cavendish Professionals in London is seeking a founding Backend Engineer to own the 0-to-1 platform, building mission-critical infrastructure for healthcare billing.

You will design high-throughput data pipelines using Prefect and LakeFS, ship low-latency APIs, and apply FHIR-based logic to clinical data, working with a small, autonomous team.

Qualifications

• 2–6 years of backend engineering experience in a venture-backed startup.
• Strong architectural depth and comfort navigating ambiguity in rapid iterations.
• Experience with modern data engineering tooling, orchestration frameworks, and cloud ecosystems.
• Familiarity with clinical data standards and automated evaluation using FHIR queries is a plus.

Responsibilities

• Own end-to-end 0-to-1 platform initiatives, shipping scalable production systems.
• Design and operate high-throughput data pipelines using Prefect, LakeFS, and LLM-powered extraction for computable clinical rules.
• Architect ultra-low-latency API and MCP endpoints serving deterministic coverage rules to large-scale transactions.
• Translate domain criteria into formal logic and FHIR queries for automated evaluation against clinical data.
• Drive ongoing engineering innovation with AI-assisted workflows in a lean, high-autonomy team.

Skills

Python

Distributed systems

API design

Pydantic

Rust

Education

Bachelor's degree in Computer Science, Mathematics, or Engineering

Tools

Prefect

LakeFS

AWS

Railway

Job description

Founding Backend Engineer | Python & Distributed Systems | LLM-Powered Healthcare Infrastructure

We are seeking an exceptional, backend-leaning Founding Software Engineer to join a high-caliber four-person team building mission-critical infrastructure that makes healthcare billing deterministic. Backed by $100M in committed funding and a landmark design partnership with a $12B industry leader, this is a rare 0-to-1 opportunity to shape the core platform architecture tackling a massive $200B+ market from the ground up.

What You’ll Be Doing:

• Taking complete end-to-end ownership of 0-to-1 platform initiatives, independently identifying high-leverage architectural gaps and shipping scalable production systems.
• Designing and operating high-throughput data pipelines using Prefect, LakeFS, and LLM-powered extraction to turn unstructured policy documents into computable clinical rules.
• Architecting and scaling ultra-low-latency API and MCP endpoints serving deterministic coverage rules to millions and billions of transactions.
• Translating complex domain criteria into formal logic and FHIR queries for automated, deterministic evaluation against clinical data.
• Driving continuous engineering innovation by experimenting with AI-assisted workflows, agentic coding tools, and autonomous pipelines within a lean, high-autonomy team.

What We’re Looking For:

• 2–6 years of commercial backend engineering experience building and scaling production systems at a venture-backed startup (Series A–D).
• Problem-first engineering mindset with strong architectural depth and comfort navigating ambiguity in rapid iterations.
• Strong foundational degree in Computer Science, Mathematics, or Engineering.
• Experience working with modern data engineering tooling, orchestration frameworks, and cloud ecosystems (AWS, Railway, Prefect, LakeFS).
• Passion for cutting-edge developer velocity, modern AI tooling, and agentic workflows.

Must-Haves:

• Deep hands-on production engineering experience in Python (with strong typing frameworks like Pydantic).
• Proven experience building high-scale distributed backend systems; background in lower-level languages (Rust, C/C++) is a strong signal of engineering depth.
• Existing UK Right to Work or a transferable visa (no new visa sponsorship available).
• Full availability to work on-site 5 days a week at the office in Hoxton, London (relocation support available).

Location & Working Setup:

• On-site model: 5 days per week based out of Hoxton, London (relocation support provided if relocating to London).