Data Engineer

Harnham; Greater London; On-site; GBP 70,000 - 110,000; Full time

Job summary

Harnham partners with a rapidly growing YC-backed healthcare AI startup building a market-leading data platform used by pharmaceutical, biotech and healthcare organisations. The team seeks engineers who take products from 0-1, owning end-to-end delivery.

You will build scalable ETL/ELT pipelines in Python and SQL, design ingestion frameworks, and work with large, messy datasets, leveraging AI/LLM technologies to extract, classify and enrich data, delivering production-ready data products for

Qualifications

• Strong Python and SQL skills.
• Proven ownership of end-to-end engineering projects.
• Experience building products, platforms or major capabilities from 0-1.
• Ability to operate independently in a fast-moving environment.
• Strong problem-solving skills and technical foundations.

Responsibilities

• Build scalable ETL/ELT pipelines using Python and SQL.
• Design and develop data ingestion frameworks.
• Work with large, complex and often messy datasets.
• Leverage AI and LLM technologies for extraction, classification and enrichment.
• Build data products that directly support customers.
• Design schemas, entity resolution and data quality processes.
• Collaborate with engineering, product and leadership teams.
• Take projects from concept through to production deployment.

Skills

Python

SQL

Ownership

0-1 projects

Data pipelines

Tools

Snowflake

Databricks

Cloud platforms

Job description

We're working with a rapidly growing, YC-backed healthcare AI startup building a market-leading data platform used by pharmaceutical, biotech and healthcare organisations.

The Opportunity

This is not a role where you'll maintain legacy pipelines or work on a small corner of an established platform. The team is specifically looking for engineers who have experience taking products, platforms or major features from 0-1.

You should be able to demonstrate that you've:

• Built something from scratch rather than simply maintained existing systems
• Worked through ambiguity with limited requirements
• Designed architecture and made key technical decisions
• Owned delivery from idea through to production
• Worked closely with product teams, users or founders to shape solutions
• Shipped products that generated real business value

The successful candidate will help build and scale the core data infrastructure powering the company's platform, taking ownership of projects from raw data acquisition all the way through to production-ready products.

What You'll Be Doing

• Building scalable ETL/ELT pipelines using Python and SQL
• Designing and developing data ingestion frameworks
• Working with large, complex and often messy datasets
• Leveraging AI and LLM technologies for extraction, classification and enrichment
• Building data products that directly support customers
• Designing schemas, entity resolution and data quality processes
• Collaborating closely with engineering, product and leadership teams
• Taking projects from concept through to production deployment

What We're Looking For

• Strong Python and SQL skills
• Proven ownership of end-to-end engineering projects
• Experience building products, platforms or major capabilities from 0-1
• Ability to operate independently in a fast-moving environment
• Strong problem-solving skills and technical foundations

Highly Desirable

• Startup or scale-up experience
• Experience working directly with founders or product teams
• LLMs, AI tooling or prompt engineering exposure
• Data acquisition, scraping or ingestion experienceSnowflake, Databricks or modern cloud data platforms
• Experience turning technical outputs into customer-facing products

The Person

We're looking for someone who enjoys building rather than maintaining.

You'll thrive here if you get energy from starting with a problem, designing a solution and seeing it through to production. The ideal candidate will have a track record of operating in environments where ownership is high, processes are light, and shipping quickly matters. Years of experience are less important than evidence of what you've actually built.

Package

• Opportunity to join a high-growth, YC-backed startup
• Significant ownership and autonomy
• Chance to help shape the future of a data-first AI product