# Data Scientist at Blenheim Chalcot

> United Kingdom · Unspecified · Analytics / Data science · open. Source: https://alderhq.app/jobs/greenhouse%3Ablenheimchalcot%3A8208245 (read 2026-11-05).

## Facts (observed)

- Company: [Blenheim Chalcot](https://alderhq.app/companies/blenheim-chalcot)
- Location text: London; Fospha - London
- Where it can be done from (inferred): United Kingdom (evidence: "Location: London; Fospha - London")
- Posted: 2026-09-24 (42 days ago)
- First seen by alder: 2026-11-02 · last verified: 2026-11-04
- Reposted: 0 times · edited: 0 times
- Apply on the employer's site: https://job-boards.greenhouse.io/blenheimchalcot/jobs/8208245
- Skills listed (inferred): Python, SQL

## Pay and sponsorship

- Posted pay: not posted
- Market band for similar posted roles (London, n 9): p25 £80k, median £85k, p75 £100k

## Description (the employer's text)

Fospha is the measurement system enterprise retail and ecommerce brands run their business on. We give marketing teams one clear, daily view of what's actually working — across every channel and everywhere they sell, from their website to Amazon and TikTok Shop — down to the level of a single ad or piece of creative. It replaces guesswork and gut feel with a number marketing, finance and agencies can all trust and act on.

Brands including Dyson, Gymshark, Adanola and Huel use Fospha up to 25 times a day to decide where budget should move next. We've spent over a decade building this, with more than $40 billion in marketing spend now optimised through the platform — and we're scaling fast across London, Mumbai and Austin.

### About the role

We're looking for a Data Scientist to join Fospha's Data Science team in London.

Fospha builds marketing measurement products for ecommerce brands — attribution, marketing mix modelling, incrementality testing, and brand impact measurement. Our Data Science team owns the models behind all of it, from methodology through to production code. You will work across our technical stacks and own maintaining and growing the codebases that power our product and solutions.

This role suits an established data scientist who wants to own things properly. You'll lead larger production projects, choose the modelling approach rather than being handed it, and talk to clients as the modelling expert in the room — supported by a team that reviews each other's work seriously, and a company that rewards high agency with ownership.

Team: Data Science

Level: Career (Data Science Career Development Framework)

Location: London

### What you'll do

- Lead larger production projects end to end — scoping, building, and shipping production-level code, rather than working through tickets someone else has specified
- Choose the modelling approach — independently selecting and applying the right method within our suite, across attribution, marketing mix modelling, incrementality testing, and brand impact. You will be given time to keep up-to-date on the latest methodologies in the industry
- Resolve bugs and queries independently — including in parts of the codebase you didn't write, without needing to route them upwards
- Use AI as leverage, not as a crutch — solving coding tickets quickly, unblocking yourself on product and engineering dependencies, and building automation workflows that save the team time
- Work with QA properly — using our automated tooling efficiently and flagging the gaps in it rather than working around them
- Communicate as a modelling expert — confidently and independently, with clients and with colleagues, including when the message is that a number they like is wrong
- Help develop the people around you — code review, methodology critique, and hands-on support for less experienced colleagues. Breaking down tickets and helping those more junior is essential
### What we're looking for

### Essential

- Solid commercial data science experience — typically 3–5 years, with a track record of shipping models into production
- Strong ML knowledge across multiple algorithm families, and the judgement to pick the right approach for the problem rather than the one you know best
- Strong Python and SQL, with the ability to lead on production-level code and set the standard others work to
- Able to debug and resolve issues independently across unfamiliar repositories, using AI tooling to accelerate rather than to guess, while still understanding the problem fully
- Strong AI fluency — you solve tickets quickly with it, you unblock cross-department dependencies with it, you build automation workflows with it, and you never send AI-assisted output without checking it
- Confident, independent communication with clients and stakeholders as the technical authority on the work
- Emerging mentorship — you're ready to develop junior colleagues, and you want to
- Initiative in accepting and planning your own work, rather than waiting to be allocated it
- Genuine attention to detail — much of this work involves noticing when a number is wrong

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Data: alder (https://alderhq.app). Cite https://alderhq.app/jobs/greenhouse%3Ablenheimchalcot%3A8208245 and the date you read it. Observed facts come from the employer's own listing; location reach, level, family and skills are inferences.