Senior/Principal Data Engineer

Job Title: Senior/Principal Data Engineer

Salary: £100-150k (DOE) + equity, bonus and private healthcare

Location: Central London (2-3 office days/week)

VISA sponsorship is NOT available

This is a rare one. A Sequoia and General Catalyst-backed startup is building the operating system for UK police forces — combining AI-powered investigation software with smart hardware to give officers real-time data and cut administrative burden.

Founded by a genuinely exceptional team: one founder is the youngest Chief Constable in UK history and previously bootstrapped and sold a PoliceTech product into every UK force in the country within 18 months. The other founder comes from sovereign wealth fund investing. The company has already signed pilots and has live on-site deployments running, with a small (10-person), high-calibre engineering team in London.

Why this hire matters

This is the most business-critical hire in the company right now. A live on-site deployment is underway and needs stronger data ingestion and infrastructure, fast. You'll join as a founding hire and own the data engineering layer, building pipelines that ingest, reconcile and normalise data from deeply fragmented legacy systems across different police forces. Every force runs different infrastructure: different clouds, different telephony systems, different software stacks, no consistent APIs. This team's job is to make sense of all of it.

This is explicitly not a greenfield role. The hard, valuable part of the work is operating without greenfield assumptions.

You'll work on:

• ETL/ELT pipelines extracting and normalising data from legacy operational platforms
• Schema reconciliation and event-record joins underpinning core product features
• Data anonymisation and synthesis pipelines for a highly sensitive, regulated environment
• Event-sequence and temporal data modelling across operational datasets
• Close collaboration with the Chief AI Scientist, Head of Software and a Founding Engineer

What we're looking for

We want a broad builder who can cover most of the surface area well, not a narrow specialist. Ideally you've blended startup pace (short iterative cycles, owning problems without perfect structure) with exposure to larger, more complex environments.

Must-have:

• Proven experience with sensitive PII or health-equivalent data in a regulated environment (health, finance, government, defence, legal)
• Production AWS experience with infrastructure as code (Terraform or Pulumi ) that you've written and run yourself, including networking, IAM and security basics, rather than handing it to a platform team
• Genuine comfort with messy, legacy enterprise systems or non-uniform sources — fragmented infra, inconsistent schemas, limited or no APIs
• ETL/ELT pipeline development, schema mapping and reconciliation at scale
• Strong Python and SQL
• First or sole data engineer who turned fragmented data into a governed platform
• Multi-cloud fluency (AWS, Azure, GCP). Every force is different, so cloud agnosticism matters
• Data governance, lineage and quality tooling
• Background in NHS Trust data engineering, police systems, government or civil service data infrastructure
• Zero-copy or virtualisation-first architecture experience

Nice to have:

• Airflow, dbt, Spark, Kafka or similar
• UI-based ingestion tooling for legacy systems without usable APIs
• Video or streaming data experience
• TypeScript

Important:

this role requires UK national status or 3+ years of continuous UK residency, as security vetting is mandatory with no exceptions.

What this isn't:

this isn't a fit if you've only worked on clean, modern stacks where the data arrives tidy. The best candidates have walked into a fragmented data estate, in a startup, scale-up or enterprise, and made it reliable.