Principal Machine Learning Engineer (L5/L6/L7)
New York / $600000 - $15000000 annum
INFO
$600000 - $15000000
LOCATION
New York
Permanent
Principal Machine Learning Engineer - Recommendation & Relevancy
Location: New York (Hybrid - 4 days onsite)
Compensation: $600,000 - $1,500,000 total package
(Base Salary: $360,000-$400,000 + Equity + Exceptional Benefits)
THE COMPANY
Join a hyper-growth global e-commerce innovator that's reshaping how businesses deliver real-time, personalized experiences at the point of purchase. Leveraging cutting-edge AI and ML at massive scale, this organization is building the future of intelligent commerce-and you could be a key part of it.
With explosive growth, a high-caliber team, and a tech-first culture, this is a unique opportunity to drive meaningful impact in a fast-paced, data-driven environment.
THE ROLE
As a Principal Machine Learning Engineer, you'll drive the design and deployment of large-scale, intelligent decision-making systems. From personalized recommendations to smart bidding and real-time optimization, your work will directly influence millions of transactions and customer experiences daily.
You'll collaborate closely with product and engineering partners to build ML solutions that are both cutting-edge and production-ready.
Key Focus Areas:
- Smart bidding and budget pacing algorithms
- Real-time recommendation engines
- Lookalike modeling and customer targeting
- CTR/CVR modeling and conversion optimization
Responsibilities:
- Architect and deploy end-to-end ML solutions at scale
- Develop robust data pipelines, feature stores, and orchestration frameworks
- Build high-performance, production-grade ML models (batch & real-time)
- Lead experimentation (offline & online), including A/B testing and model tuning
- Drive engineering excellence with well-tested, maintainable, scalable code
- Mentor team members and contribute to a culture of technical growth
YOUR SKILLS & EXPERIENCE
- PhD or Master's degree in Machine Learning, Computer Science, or a related field
- 10+ years of hands-on experience building production ML systems at scale
- Expertise in AWS, TensorFlow, Feature Store technologies, and orchestration tools (e.g., Kubeflow, Airflow)
- Deep knowledge of at least two of the following:
- Bayesian methods
- Recommender systems
- Multi-task or meta-learning
- CTR/CVR prediction models
Bonus: Experience with advanced model architectures like Deep & Cross Network v2, Multi-gate Mixture-of-Experts, or Deep & Wide Networks.
BENEFITS
- Significant equity in a high-growth tech company
- Premium, fully covered health insurance (you + family)
- 401(k) with 4% dollar-for-dollar match
- Catered lunches and daily snacks
- Global travel opportunities
- Inclusive, collaborative culture with a strong focus on innovation, diversity, and impact
✅ HOW TO APPLY
Ready to solve real-world problems at scale and push the boundaries of applied machine learning? Apply now to speak with one of our specialist recruiters and learn more about this high-impact opportunity.
CONTACT
Luc Simpson-Kent
Senior recruitment Consultant
SIMILAR
JOB RESULTS
Content Writer
London
£275 - £300
+ Digital Analytics
ContractLondon
To Apply for this Job Click Here
Content Writer – Contract
Start: Mid-August 2025
Duration: 3 months
Location: Remote (UK-based)
Day Rate: £275-300 Outside IR35
We’re supporting a major healthcare brand through a transformative website launch project, and we’re looking for a skilled content writer to join the team on a contract basis.
What’s the project about?
This is a brand-new CMS build, involving over 1300 pages of content – from condition overviews and treatment guides to symptoms and diagnostic test pages. This isn’t a copy-paste exercise – the team is conducting a full content audit and prioritisation process to ensure accuracy, clarity, and relevance across the new site.
You’ll help migrate, rewrite, and optimise existing content into new page templates. Content will be drafted in Google Docs and later uploaded by in-house interns.
What you’ll be doing day-to-day:
-
Reviewing and rewriting healthcare content directed at patients
-
Working from a list of URLs to assess current content and allocate by specialism
-
Mapping and transferring content into new page templates (700+ templates)
-
Identifying gaps and creating new content as needed
-
Collaborating with an in-house copywriter and small content team
-
Using style guides to ensure consistency
-
Writing into Google Docs for later CMS implementation
What success looks like:
-
High-quality, patient-friendly healthcare content ready for CMS upload
-
SEO best practices followed and style guides adhered to
Key skills we’re looking for:
Must-haves:
-
Strong healthcare writing experience (patient-facing content)
-
SEO understanding – using style guides and keyword awareness
-
Meticulous attention to detail – layout, formatting, grammar, and consistency
Nice-to-haves:
-
Excellent spelling and grammar
-
Experience working in CMS migrations or large-scale web projects
Ideal background:
-
Healthcare sector experience is essential
-
If not healthcare, experience in hospitality may be considered
-
Able to start mid-August and commit flexibly through September
Please reach out to Grace McCrudden at Harnham for more info
To Apply for this Job Click Here
Looker Consultant
City of London
£400 - £450
+ Advanced Analytics & Marketing Insights
ContractCity of London, London
To Apply for this Job Click Here
LOOKER CONSULTANT
£400 – £500 PER DAY OUTSIDE IR35
LONDON (2/3 DAYS IN THE OFFICE)
3-MONTH CONTRACT
THE COMPANY:
Join a growing tech company and lead their migration project from Tableau to Looker.
THE ROLE:
As a Looker Consultant, you will play a pivotal role in assisting the company’s migration from Tableau to Looker. Key responsibilities will include:
- Leading the migration process of existing Tableau dashboards and reports to Looker.
- Working closely with stakeholders to ensure data accuracy and quality.
- Developing and maintaining Looker dashboards and reports.
- Providing training and support to end-users on Looker dashboards.
YOUR SKILLS AND EXPERIENCE:
To excel in this role, you should possess the following skills and experience:
- Proven experience as a Looker Consultant.
- Hands-on experience with Tableau, including migrating or re-creating dashboards in Looker.
- Strong SQL skills.
- Excellent communication skills.
HOW TO APPLY:
Please register your interest by sending your CV to Mojola Coker via the apply link on this page.
To Apply for this Job Click Here
Principal Software Engineer
City of London
£100000 - £120000
+ Data Engineering
PermanentCity of London, London
To Apply for this Job Click Here
PRINCIPAL SOFTWARE ENGINEER
CITY OF LONDON – 4/5 DAYS IN OFFICE
£100,000 – £120,000
Our client, a leading investment management firm specialising in sports trading, is looking for a talented individual to join their expanding technical team. This is a unique opportunity to apply your expertise to real-world sporting events and contribute to a company with exceptional team retention and a collaborative culture.
THE COMPANY:
Founded in THE 2000s, this organically growing investment management firm has carved out a niche in the dynamic world of sports trading. With a turnover exceeding £10 million last year, they trade globally across various sports. Their technical team of 30 is at the heart of their success, and these new roles are crucial as they continue to build out their core functions.
You’ll be joining a company that prides itself on a strong, fluid culture, offering significant autonomy and a genuine commitment to work-life balance and flexibility. Their high team retention speaks volumes about the supportive and engaging environment they’ve cultivated.
THE ROLE:
As a Principal Software Engineer, you’ll be instrumental in developing sophisticated predictive models that forecast the outcomes of sporting events. You’ll be working with strong quants coming from and statistics background, with a keen eye for problem-solving. You’ll work across the full stack, contributing to both front-end and back-end development.
This is a hands-on technical role and whilst a background in sports trading isn’t essential, an interest in sports, particularly in a quantitative context, would be a plus. You’ll be joining a collaborative environment where you have the opportunity to work cross-functionally and significantly impact the company’s core operations.
YOUR SKILLS AND EXPERIENCE:
The ideal Principal Software Engineer will have:
- Strong mathematical and statistical expertise, ideally from a quantitative background.
- Proficiency in C# and the .NET platform.
- Experience with JavaScript front-end frameworks, such as React.
- Solid understanding of Network Programming (TCP/UDP).
- Experience with Distributed Version Control systems (e.g., PlasticSCM, Git, Hg).
- A history of good tenure in previous roles.
HOW TO APPLY:
Please register your interest by sending your CV via the Apply link on this page.
To Apply for this Job Click Here
Graphics Engineer
London
£110000 - £180000
+ Data Engineering
PermanentLondon
To Apply for this Job Click Here
Role: Graphics Engineer
Location: Central London (Hybrid 2-3 days per week preferred)
Salary: Flexible, depending on experience
Our client – a VC-backed AI platform co-founded by ex-Meta leaders – is hiring a Graphics Engineer to help build a custom graphics engine from the ground up in Rust.
This is a high-impact role where you’ll work on cutting-edge rendering and animation pipelines that power the core of their product, designed to help designers and non-designers alike generate personalised content across video, 2D, and 3D formats. You’ll be joining a small, highly technical team during a period of hypergrowth, with early access to major funding and a product launching imminently.
Key Focus Areas:
-
Design and implement a high-performance graphical engine in Rust
-
Build and optimise real-time rendering pipelines for 3D, video, and infinite canvas environments
-
Lead or support the export and compression of animations and visual assets
-
Collaborate across a cross-functional team (Rust, C++, Node.js)
What We’re Looking For:
-
Strong hands-on experience with Rust and graphics/rendering systems
-
Proven experience in real-time rendering, game engines, or animation pipelines
-
Background in video, 2D/3D graphics, or visualisation tools
-
Bonus: Experience with WebAssembly, Node.js, C++, or compression/export tooling
-
Leadership or ownership experience is a strong plus
To Apply for this Job Click Here
Principal Graphics Engineer
London
£120000 - £150000
+ Data Science & AI
PermanentLondon
To Apply for this Job Click Here
PRINCIPAL GRAPHICS ENGINEER (RUST)
LONDON – 3 DAYS PER WEEK
£150,000 + BENEFITS
Are you a passionate Graphics Engineer with deep expertise in Rust, eager to build a revolutionary custom graphical engine? Join a hyper-growth AI platform, backed by top VCs, that’s set to transform content creation for designers and non-designers alike.
THE COMPANY:
Our client is an innovative AI platform poised for rapid expansion, having secured significant pre-seed funding. They’re building an AI-powered assistant that empowers users to create highly personalized content across video, graphic design, 2D, and 3D data. They’re expanding fast, with product launch imminent and further funding planned.
THE ROLE:
As a Graphics Engineer (Rust), you’ll be a core member of a small, agile team, building a groundbreaking custom graphical engine in Rust. This engine will support video, 3D animations, and run on an infinite canvas, forming the backbone of their AI design platform.
Your focus will be on rendering visuals (from initial output to real-time) and implementing robust export and compression solutions for 3D assets, animations, and videos. This role requires deep Rust and animation/rendering knowledge.
YOUR SKILLS AND EXPERIENCE:
Essential:
- Rust Expertise and strong Graphics Rendering knowledge.
- Familiarity with Web Graphics/Rendering.
- Comfortable in a fast-paced, evolving startup.
Highly Desirable:
- Node.js, C++, WebAssembly, real-time rendering, or video/3D pipeline tools.
- Experience in game development, design tools, or animation platforms.
- Familiarity with compression/export pipelines.
HOW TO APPLY:
Please send your CV via the Apply link on this page.
To Apply for this Job Click Here
Head of Data & AI
London
£110000 - £130000
+ Data Engineering
PermanentLondon
To Apply for this Job Click Here
Role: Head of Data & AI
Location: Central London (hybrid 2-3 days a week in office)
Salary: £130,000 + Benefits
Our client is hiring a Head of Data & AI to lead the transformation of their data function across engineering, analytics, governance, and applied AI/ML.
This is a high-impact leadership role where you’ll define the data strategy, build out a top-tier team, and partner with senior leaders across product, tech, and risk. You’ll also play a key role in the organisation’s AI roadmap – ensuring scalable, ethical, and secure use of machine learning.
Key Focus Areas
- Own and execute enterprise data strategy
- Build and lead a multi-disciplinary data & AI team
- Drive modern data platform development (dbt, Airflow, Snowflake, Looker/Power BI)
- Deliver business-critical analytics and reporting
- Support responsible AI/ML initiatives
- Define data governance, privacy, and compliance frameworks
What We’re Looking For
- Proven data leadership in fintech, SaaS, or cloud-native environments
- Strong technical background in data engineering, analytics, or science
- Experience working with Finance and Risk teams
- Familiar with AWS and modern data/AI stacks (SQL, Python, MLflow, MLOps)
- Strategic mindset with ability to scale teams and influence at C-level
To Apply for this Job Click Here
Technical Architect
Manchester
£500 - £650
+ Advanced Analytics & Marketing Insights
ContractManchester, Greater Manchester
To Apply for this Job Click Here
Technical Architect
Location: Manchester (Hybrid)
Duration: 3 months initially – flexible days
IR35 Status: Outside IR35
Day Rate: Competitive
We’re initiating a key project to migrate away from our current third-party MSP and are seeking an experienced Technical Architect to lead the design and planning phase – with potential to remain involved through delivery.
We are looking for someone who has experience migrating Active Directory, Outlook, and Office environments from third-party providers to on-prem, hybrid, or cloud platforms.
About the Role
This project will be delivered in two phases:
Phase 1 – Discovery & Design:
-
Evaluate 2-3 migration approaches and outline the pros and cons of each.
-
Develop a clear High-Level Design (HLD) for the preferred migration strategy.
-
Collaborate with internal stakeholders to ensure alignment and readiness.
Phase 2 – Delivery Oversight:
-
If the design is approved, you’ll continue into the delivery phase.
-
Provide architectural governance and, where needed, hands-on support during the migration.
Key Skills & Experience:
-
Proven experience delivering infrastructure or cloud architecture projects.
-
Strong background in migrating Active Directory, Outlook, and Office environments from third-party providers to on-prem, hybrid, or cloud platforms.
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Demonstrated success in large-scale MSP transitions or enterprise IT migrations.
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Ability to create and present clear HLD/LLD documentation.
-
A consultative and confident communicator who can advise, challenge, and lead stakeholders.
To Apply for this Job Click Here
Senior Credit Risk Analyst – German Markets
London
£60000 - £80000
+ Risk Analytics
PermanentLondon
To Apply for this Job Click Here
SENIOR CREDIT RISK ANALYST – GERMANY
£80,000
LONDON (3 days p/w)
THE COMPANY
This is an exciting opportunity with an ambitious FinTech that focus on harnessing data to enhance their lending decisions. This business have been growing in recent years and are now in an excellent position where they are targeting further success across multiple geographies.
THE ROLE
- Driving the development of a wide range of credit risk and pricing strategies across the lending book, specifically for the German market
- Using statistical models and wider analytical tools to drive insight into book performance
- Wider work on customer analytics and behavioural trends, including work on acquisition and underwriting
- Close stakeholder interaction and work with internal teams
YOUR SKILLS AND EXPERIENCE
- Previous experience in and knowledge of SQL is essential
- Experience in developing credit risk strategies is essential
- Prior work with the German lending market is essential
- Experience with SME or wider business lending is highly desirable
SALARY AND BENEFITS
- Base salary of up to £80,000
- Discretionary Bonus
- Company pension scheme
- Company equity
- 25 days holiday
HOW TO APPLY
Please register your interest by sending your CV to Rosie Walsh through the ‘Apply’ link
To Apply for this Job Click Here
Senior Software Engineer (C#/.Net)
London
£100000 - £130000
+ Data Engineering
PermanentLondon
To Apply for this Job Click Here
Full-Stack C# Developer
Sports Analytics & Trading | London (5 days in Office)
Up to £130k+
Are you a C#/.NET developer who thrives in fast-paced, high-intellect environments? I’m hiring for a tight-knit, high-performing software team working at the intersection of sports analytics, automated trading, and modern software development. You’ll help drive greenfield product development from the ground up, with full autonomy and no bureaucracy.
This is a rare chance to work on complex systems with tangible outputs, in a space where performance, precision, and experimentation rule.
Why This Role?
-
Salary up to £100,000 (DOE)
-
Intellectual, collaborative culture with top-tier developers and researchers
-
Hybrid setup in Central London – expect autonomy, ownership, and flexibility
-
Greenfield projects – make architectural decisions and ship fast
-
No prior trading or sports market experience required – just strong engineering skills
Tech Stack
-
C# / .NET (Latest versions)
-
SQL Server, plus experience with Oracle or equivalent
-
Bonus: exposure to JavaScript/React, multi-threading, or network programming (TCP/UDP)
What You’ll Be Doing
-
Build and maintain internal tooling that powers automated sports market trading
-
Contribute to greenfield systems, from design through to production
-
Collaborate with researchers and devs on experimentation and rapid iteration
-
Write high-quality, scalable, performant code in a flat, agile structure
-
Engage with real-time systems and data-heavy platforms (where accuracy is everything)
What We’re Looking For
-
Solid experience with C# and the .NET platform
-
Good grounding in SQL and relational database design
-
Strong attention to detail and code quality
-
Excellent written and verbal communication
-
A scientific, curious mindset – and ideally a degree in CS or a STEM subject
Nice to have:
-
Experience with React or modern JS frameworks
-
Multi-threaded or low-latency application experience
-
Familiarity with Git, PlasticSCM, or other DVCS tools
Perks & Benefits
-
Pension, private health insurance, gym membership
-
Daily snacks, fruit, (and the occasional pizza + cake!)
-
Support for work-life balance and wellness
-
A culture that values smart ideas over hierarchy
To Apply for this Job Click Here
Senior Pricing Data Scientist
City of London
£75000 - £85000
+ Risk Analytics
PermanentCity of London, London
To Apply for this Job Click Here
Senior Pricing Data Scientist
London
Hybrid (1 day per week in office)
Up to £85,000
Company:
I’m hiring for a fast-growing InsurTech that’s reshaping how insurance pricing is done. They’ve attracted major investment and are building out a best-in-class pricing and data science team to support their rapid growth. As a Senior Pricing Data Scientist, you’ll play a key role in designing and deploying advanced pricing models that directly impact revenue and profitability
The Role:
- Build and deploy pricing models using statistical and machine learning techniques
- Analyse large datasets to understand risk and performance across products
- Develop pricing strategies that support customer growth and profitability
- Work closely with engineering and product teams to integrate models into live systems
- Modelling market insurance premiums on/for aggregators
- Present pricing insights and strategy recommendations to senior stakeholders
Experience Required:
- Experience in insurance pricing (motor, home, travel, or similar)
- Strong Python and SQL skills
- Experience building pricing models (GLMs essential, ML models a plus)
- Experience modelling insurance premiums
- Strong communication skills, comfortable working with senior stakeholders
- Degree in a STEM subject
Benefits:
Up to £85,000 base salary
To Apply for this Job Click Here
Credit Strategy Manager
City of London
£90000 - £110000
+ Risk Analytics
PermanentCity of London, London
To Apply for this Job Click Here
Credit Strategy Manager
Up to £110,000
Hybrid
London
The Company
I am hiring a Credit Strategy Manager leading consumer finance FinTech’s based in London. Within this role you will be bringing your acquisitions and ECM strategy experience to focus on driving business growth through acquisitions and revenue from existing using tools like SQL and Python alongside your credit strategy background!
The Role
As a Credit Strategy Manager, you will be:
- Developing new insights to drive optimisation of credit risk strategies.
- Detecting new trends on customer data to help increase business revenue
- Developing credit risk strategies for Acquisitions and existing customers
- Working with senior leadership to implement/improve strategy.
- Using SQL and Python daily for strategy development
Your skills and experience
To be successful as a Credit Strategy Manager, you will need:
- Experience as a credit risk strategy manager/lead
- Experience working in a fast-paced environment
- Experience developing credit risk strategies for Acquisitions
- Ideally some experience developing ECM and Collections strategies
- Experience working on unsecured lending products, like credit cards and/or loans
- Experience working with SQL and Python
- STEM Degree from a top university
Benefits
Up to £110,000 + Benefits
To Apply for this Job Click Here
Senior Credit Strategy Analyst
City of London
£65000 - £75000
+ Risk Analytics
PermanentCity of London, London
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Senior Credit Strategy Analyst
Up to £75,000
Hybrid
London
The Company :
I am hiring a Senior Credit Strategy Analyst leading dynamic FinTech based in London. Within this role you will be bringing your credit risk strategy experience to focus on driving business growth and profitability using tools like SQL and Python daily!
The Role :
As a Senior Credit Strategy Analyst, you will be:
- Developing new insights to drive optimisation of credit risk strategies.
- Detecting new trends on customer data to develop wider business strategies
- Developing credit risk strategies for Acquisitions and Existing Customers.
- Working with senior leadership to implement/improve strategy.
- Using SQL and Python daily for strategy development
Your skills and experience :
To be successful as a Senior Credit Strategy Analyst, you will need:
- Experience as a credit risk strategy analyst
- Experience working in a fast-paced environment
- Experience developing credit risk strategies for Acquisitions and/or Existing Customer
- Experience working with SQL and Python
- STEM Degree from a top university
Benefits
Up to £75,000 + Benefits
To Apply for this Job Click Here
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