Top Python Jobs in London

Lead detection and response activities within global security operations: investigate incidents, tune security tools, perform network security assessments, coordinate remediation, research vendor solutions, act as SME, and improve security posture across IT and business teams.

Lead design and implementation of scalable backend and frontend systems, own domains end-to-end, set technical strategy and architecture, mentor engineers, drive cross-team initiatives, and improve reliability, performance, testing, monitoring, and CI/CD for customer-facing microservices.

Lead the design and delivery of AI-based solutions for enterprise customers, ensuring successful integration and optimization across multiple projects, while mentoring junior engineers.

Build scalable automation to generate regulatory and financial reports from large warehouse data sets. Lead technical design, development, code review, reconciliations, and collaborate with Compliance, Finance, and Treasury to meet regulatory obligations.

As a Senior Business Analyst (Valuations), you will analyze economic value, build models, conduct testing, and collaborate with cross-functional teams to inform business decisions.

Conduct end-to-end ML research for options trading: design experiments, train large-scale models (LLMs/transformers), build scalable pipelines, validate and deploy models to production, and translate research into measurable P&L impact.

Customer-facing engineering role building and deploying AI-powered observability solutions. Design, implement, and support integrations, backend services, telemetry pipelines, and full-stack artifacts using Python, Java, and JavaScript/TypeScript. Drive production rollouts, troubleshooting, and codify repeatable templates and playbooks to improve adoption and product feedback.

Own end-to-end prudential regulatory reporting for capital and liquidity, validate and challenge report outputs, deliver management commentaries, map and ETL data, lead reporting system enhancements with vendors and data teams, manage UAT and controls, and maintain documentation and reporting controls to ensure regulatory compliance.

Lead complex Professional Services engagements delivering advanced LogicMonitor integrations and automations. Design, code, test, and deploy custom solutions using APIs and cloud services, troubleshoot issues, drive product improvements, mentor engineers, and collaborate with Product, Customer Success, and Support.

Lead architecture, performance, and reliability for a Kubernetes-native inference platform. Implement inference optimizations (speculative decoding, KV-cache reuse), define benchmarking and observability, drive cross-team initiatives, and improve tail latency, autoscaling, and capacity planning under strict P99 SLAs.

Partner with financial crime product teams to build and monitor screening controls. Own metrics, run discovery analyses, build and maintain data pipelines, create reports and visualisations, and translate insights into product changes that balance risk mitigation with customer experience.

Lead data architecture and resiliency for marketing data pipelines. Build scalable Airflow/dbt workflows, productionize CDP datasets, own MarTech integrations, bridge engineering and analytics, and mentor engineers to improve reliability and observability for high-volume streaming and batch systems.

Lead design and productionization of scalable streaming and batch data pipelines (Python, Kafka, Trino, Iceberg). Build unified customer datasets using Airflow and dbt, own MarTech integrations, set data architecture and reliability standards, partner with analytics and marketing, and mentor engineers.

Provide hands-on production and demo trading exchange support: monitor availability and performance, run daily operations, triage incidents, support releases, maintain runbooks, automate processes, and collaborate across Dev/QA/Infra teams in a 24/7 rotational model.

Develop, implement, and deploy ML models for lodging search ranking and personalization. Design experiments and A/B tests, perform feature engineering and model evaluation, collaborate with product and engineering, monitor production model performance, and apply AI/ML best practices for scalable, explainable solutions.

Join the Indexes New Product Development team to design, develop, validate, and launch thematic and smart-beta indexes. Collaborate with research and product teams, build portfolio construction and analytics tools using statistical and machine learning methods, explore AI implementations, and produce white papers, factsheets, and client-facing materials to support product launches.

Lead product and execution consulting for algorithmic equity trading: analyze algo performance and client usage, deliver data-driven product enhancements, engage clients and sales, partner with technology and quant teams, ensure regulatory and compliance adherence.

Lead infrastructure engineering for proxy and secure web gateway solutions: manage stakeholders, troubleshoot proxy issues, deploy and automate proxy security systems, improve runbooks/change processes, mentor engineers, and align solutions with organizational goals.

Develop and back-test private credit and private asset risk factor models; productionize models with partner teams; maintain model governance (monitoring, documentation, remediation); communicate model design and performance to internal and external stakeholders; guide junior talent and support model validation.

Research and build post-training solutions for coding LLMs and agentic systems: design experiments, implement policy optimization and fine-tuning methods, translate prototypes into production, and communicate findings across teams.

As a Quantitative Researcher intern at Citadel, you'll develop models, implement trading strategies, and conduct statistical research in finance.

Design and ship consumer-facing generative AI and AR features for image/video generation and editing. Prototype models, integrate ML into production pipelines, collaborate with Product/Design/Engineering, evaluate open-source models and APIs, and iterate via A/B testing and user feedback.

Lead design and implementation of automated controls to detect and address non-compliance with Mastercard Send standards. Partner with cross-functional teams to deploy network controls, analyze transaction/customer data to improve data quality, roll out standards enforcement, support product initiatives, represent Mastercard externally, and drive continuous improvement of Send data standards.

Lead product analytics for high-volume international transfers, driving insights on verification, service quality, and predictability. Conduct causal analyses and A/B tests, set KPIs with product teams, track impact, and recommend product and support strategies to improve retention, conversion, and operational efficiency.

Own and productionise growth marketing analytics infrastructure: build scalable growth narratives, automate marketing financials and insights, develop Lightdash/Streamlit/AI tools, create payback and financial models, partner with Finance and Marketing, ensure data quality, and reduce technical debt by building reusable data components.