Senior Software Engineer, Data & Platform

Illumini; Greater London; Hybrid; GBP 85,000 - 115,000; Full time

Benefits offered by this job

Hybrid work (Liverpool Street)

6% annual bonus

Stock options

4 year vesting, 1 year cliff

12 month comp refresh

Job summary

Illumini is seeking a Senior Software Engineer, Data & Platform to own the data acquisition engine, crawling stack, and orchestration. You will ensure 95%+ coverage and build the metrics, reliability, and cost controls to scale 10x–100x as we grow toward Series A.

You will lead infrastructure improvements, drive AI-enabled tooling, and mentor junior engineers while shaping the platform to scale with the business. A hybrid UK-based role with equity and a strong compensat*ion package awaits.

Qualifications

• 5 to 8 years shipping production Python systems at Series A or B startups.
• Strong AWS. Fargate or ECS, Lambda, DynamoDB, S3, CloudWatch.
• Shipped data acquisition, crawling, or API integration at real scale.
• Owned reliability of a customer facing system.
• Experience driving infrastructure cost per customer down on live systems.
• Comfortable using AI day to day, agents for repetitive work, modern tooling.
• Backend first, but happy to do simple frontend fixes when the business needs it.
• Early-stage builder. You can take v1 code and shape it into the platform that scales.
• Systems thinker, when you touch infra, you think about cascading effects.
• Broad across the stack, crawling, data pipelines, distributed systems, cost engineering.
• Commercial about engineering, understand unit economics and business value.

Responsibilities

• Own the data acquisition engine, crawling, enrichment routing, orchestration, everything.
• Coverage at 95%+ sustained, with observability and resilience to hold it there at high volume.
• Hiring manager coverage to 95%+, matching hiring managers to vacancies.
• Infra cost per licence, driving it down as volume goes up.
• Incident response patterns, multi provider routing, reliability under load.
• Team lead track: hire and onboard engineer number two by month 6–8 if targets are hit.

Skills

Python

AWS

Data pipelines

Distributed systems

Crawling

Cost engineering

AI tooling

Tools

FastAPI

Terraform

GitHub Actions

CloudWatch

Job description

Senior Software Engineer, Data & Platform

Every new customer adds 1,000 career pages to crawl daily, scaling to 1.5M a day by Series A. We’re fixing a Google-scale problem, pointed at Staffing & Recruitment. Backed at seed by Reed, the £1BN UK Recruitment group. We need someone who loves building from an early stage and can lead the team that follows.

The problem

Illumini crawls every career page and every hiring manager relationship in the world, and turns it into signal recruiters pay for. We are at £143K ARR and are targeting £1.8M+ ARR by March 2028. Between now and then, the fleet of career pages we crawl goes from thousands to millions, and the infra cost per licence has to come down while coverage holds at 95%+.

The core problem is not building new features, it's onboarding licence after licence, holding coverage, and driving unit economics down as the system scales 10x to 100x. AI is part of how we build, held to one framework enforced in CI so every module is a readable, single-purpose block, where AI code and human code meet the same standard.

What you’ll own

• The data acquisition engine, crawling, enrichment routing, orchestration, everything. Backend-leading development, minor frontend fixes.
• Coverage at 95%+ sustained, with the observability and resilience to hold it there through 10x to 100x volume
• Hiring manager coverage to 95%+, matching hiring managers to vacancies.
• Infrastructure cost per licence, driving it down as volume goes up
• Incident response patterns, multi provider routing, reliability under load
• Team lead track. By month 6 to 8, if targets are hit, you hire and onboard engineer number two and start building the team under you

What you’ll bring

• 5 to 8 years shipping production Python systems at Series A or B startups
• Strong AWS. Fargate or ECS, Lambda, DynamoDB, S3, CloudWatch
• Shipped data acquisition, crawling, or API integration at real scale
• Previously owned reliability of a customer facing system
• Experience driving infrastructure cost per customer down on live systems
• Comfortable using AI day to day, agents for repetitive work, modern tooling where it saves time, you’re not shipping anything you don’t understand.
• Backend first, but happy to do simple frontend fixes when the business needs it
• Early-stage builder. You can take v1 code and shape it into the platform that scales.
• Systems thinker, when you touch infra, you think about cascading effects
• Broad across the stack, crawling, data pipelines, distributed systems, cost engineering, whatever you’ve gone deep on. You can own crawling AND infra AND cost architecture, and you bring one of them to Staff level
• Commercial about engineering, you understand unit economics and business value

Core stack:

Python, FastAPI, AWS, Terraform, GitHub Actions, CloudWatch.

A big plus:

experience reducing infra cost per customer on live systems with real numbers to show.

A bonus, not a must:

Staffing & Recruitment, HR tech, or data licensing background.

Why this role

Illumini is backed at seed by Reed, the £1BN UK recruitment group. One technical founder today, team of five by June 2027, team of 20+ post Series A in March 2028.

This is engineer number one, team lead track, the engine has been in production for 18 months. You take it from v1 to the platform that scales 100x into Series A. On target, by month 6 to 8 you hire engineer two & by Series A you’re leading the team.

Early equity pre-Series A at 0.5-1.5% means a meaningful payout upon exit.

Compensation and logistics

• Salary £85,000 to £115,000
• 6% annual bonus
• Stock options 0.5 to 1.5%, 4 year vest, 1 year cliff
• 12 month comp refresh pre committed if targets are hit
• 25 days annual leave + UK bank holidays
• Hybrid, Tue to Thu in Liverpool Street office
• Full time, Permanent
• Reports to Founder