Machine Learning and Quant Engineer - London

• You think in time series, signals, and regimes.
• You care about insight quality, not academic purity.
• You want your models tested by markets, not papers.
• If you dislike messy data and real-world constraints, this is not your role.

The Role, In Plain English

• You will build quantitative and ML-driven insight systems using structured time series data.
• This role exists to turn raw financial data into actionable investor signals.
• You will work closely with engineers to productionize quant logic.

What You’ll Be Responsible For

Develop models using structured financial time series

Build insight generation and scenario analysis pipelines

Collaborate with backend engineers to deploy models in production

Evaluate signals based on real investor outcomes

Improve attribution and explainability

What “Good” Looks Like in This Role

After 3 months: Shipping signals used internally.

After 6 months: Signals used by customers.

After 12 months: You shape how quant insights are built at Reflexivity.

Who You Are (Must-Haves)

5 plus years experience in quant, ML, or financial modeling

Strong Python skills

Startup experience on core systems

Investment domain knowledge

AI-assisted coding experience

Nice-to-Haves (Not Deal Breakers)

Prior buy-side or sell-side experience

Experience with alternative data

How We Work

In-office team with high trust and high ownership

Direct communication, minimal process, strong opinions backed by data

Engineers are expected to think about product impact, not just code

We move fast when it matters and slow down when correctness matters more

Why This Role Is Worth Your Time

Direct influence on how professional investors make decisions

Hard problems at the edge of AI, data, and finance

Real ownership and technical autonomy

Senior peers who care about quality and outcomes

Compensation & Practicalities

Base salary: £110,000 to £200,000 depending on experience

Equity included

In-office role based in London

No agency candidates

Salary Range

£110,000 — £200,000 GBP