You'll work across the stack building core systems from scratch using Python, C#, Go, or Java, with direct collaboration with founders on product and technical strategy. This role is at an early-stage cybersecurity start-up focused on transforming how organizations secure data and infrastructure.

You will work with TypeScript, React, Node.js, Python, and Google Cloud/AWS, building LLM-powered workflows, intelligent pipelines, and agentic systems. As the most senior individual contributor at Steven.com, you own the architecture of the company’s highest-stakes, complex systems for its creator-economy operating system. This founding-team role sets the technical bar for the whole engineering organization.

Senior Software Engineer role at Bauer Media Outdoor, working with React, Next.js, TypeScript, Node.js, Python, serverless architectures, Postgres, DynamoDB, AWS (Lambda, CloudWatch, API Gateway, S3), and Terraform. The engineer will build ad tech and programmatic buying platforms for outdoor advertising, guide system design, and mentor engineers.

You'll work with Python, TypeScript, React, AWS, and DevOps tools to build scalable software for Abtrace's primary-care platform, which helps 500+ UK practices proactively manage care for 4.5M patients. You'll own technical planning and delivery in a cross-functional squad.

You'll work with TypeScript, React, Node.js, Python, JavaScript, SQL/NoSQL databases, and AI/ML tools including LLM-based APIs. Steven.com builds an operating system for the creator economy, and you'll ship end-to-end features across internal and external products.

You'll work with Python, SQL, Linux, Docker, and legacy systems, plus desirable tools like dbt, Snowflake, Kafka, AWS, and Java. You'll develop ELT pipelines, build a streaming platform for tick data, and consolidate legacy systems for Aspect Capital, a London-based systematic hedge fund. This is a lean team owning end-to-end delivery of data ingestion and transformation.

You'll work with TypeScript, Python, and/or Rust/C++, plus cloud infrastructure and SQL/no-SQL databases. Catapult builds personalised AI models that understand your work context across email, calendar, Slack, and more. The role includes building desktop apps end-to-end and algorithmic development.

You'll work with Python, NLP/LLMs, AI/ML, cloud infrastructure, SQL/no-SQL, and optionally C++/Rust. Catapult builds personalised AI models that understand your full work context across email, calendar, Slack, Notion, and Google Docs. As a founding engineer, you'll own retrieval and reasoning systems end-to-end from research to product.

You'll work with TypeScript, React, Next.js, Node.js, Express, and PostgreSQL. The team builds financial products for African businesses, including automated payouts, payment automation, and invoice processing. You'll join a small, high-performing team shaping the product vision and technical architecture.

You'll work with TypeScript, React, NextJS, PostgreSQL, and Claude Code (or similar AI agents) to build greenfield AI products using LLMs. These tools process and extract insights from international filings, regulatory documents, and research materials for investors.

You'll build Voop's full-stack platform using TypeScript, React/React Native, Kotlin Multiplatform, Hono, Postgres, Pulumi/SST, Docker, AWS, and Kamailio. Voop creates a safe mobile network with device-integrated safeguarding and AI-driven risk detection, with its first product live protecting UK children. You'll ship production code across web, mobile, and backend services.

Staff Full Stack Engineer at Capi, working with Typescript, React, NextJS, NodeJS, Express, and PostgreSQL. The role involves building and scaling a platform for African businesses, contributing end-to-end from UI to backend logic, and working closely with the founding team in London and Paris.

Senior Software Engineer role at Syntasso, working with Golang, Kubernetes, Ruby, Rust, or Python using Extreme Programming (XP) techniques. You will design and implement features for the open-source Kratix framework and its enterprise product, helping organizations build internal platforms.

Build features using Java, Python, and MATLAB, integrating with proprietary trading systems and strategic SaaS providers while applying TDD, CI/CD, and monitoring. You will join the Software Development team at Aspect Capital, an award-winning systematic hedge fund managing over $8 billion in assets.

You'll work with Java 21, Spring Boot 3, event-driven microservices on AWS (EC2, RDS, SQS, SNS, SES, Cognito), PostgreSQL, Docker, and GitHub Actions CI/CD, using AI tools like Claude Code. Aslan builds the back-end systems that power payroll and payments for companies and their employees.

You'll use Go, gRPC, HTTP, Docker, and observability tools like Prometheus and Grafana on a modern containerised AWS stack with MySQL, DynamoDB, Redis, and Elasticsearch. The backend team designs, builds, and supports high-traffic APIs and internal tools for a community safety platform, processing tens of millions of analytic events daily with event-driven architecture and machine learning.

Build and maintain ETL/ELT pipelines using Python, SQL, BigQuery, REST APIs, and GCP tooling (Cloud Run, Cloud Scheduler, Secret Manager) to sync data between HubSpot, a People Planner, and Notion. The role owns the flow of operational data (client, revenue, pipeline) into the data warehouse and reverse ETL back into business systems used by Finance, Ops, and Client Leadership teams.

You will work with Python, TensorFlow or PyTorch, and large language models, building custom deep-learning models and training/fine-tuning LLMs on a proprietary dataset. Kangal AI builds frontier AI for governments, national security, and private corporations. As a founding hire, you will own the model stack and scale the research into a team you lead.

You will work with Python, deep learning image models, and large image/tabular datasets. The KYC Global and Onboarding Team performs Know Your Customer checks during consumer and business onboarding, implementing machine learning models to support document verification.

Use SQL, Python, and AI tools to extract and analyze large data sets on private markets and alternative investments. Work with Product and Machine Learning teams to develop data extraction from unstructured text like PDFs. The company automates alternative investment data processes for institutional investors.

Flutter Entertainment★3.9 (94)· London

In this Frontier R&D role, you will use Python and generative AI tools like ChatGPT, Claude, and Midjourney for prototyping and technology scanning. The team identifies and evaluates emerging technologies over a 12-36 month horizon for Flutter’s betting, gaming, and entertainment businesses.

Work with Python, containerized pipelines, and cheminformatics representations (SMILES, InChIKey, molecular fingerprints) to build ML evaluation benchmarks for molecular structure prediction from mass spectrometry data. You will design adversarial checks, leakage-safe datasets, and repeatable pipelines that measure model quality for an applied AI drug discovery company.

Use Python, SQL, Databricks and Spark to develop predictive models, statistical analyses and A/B tests for Primark’s Data Science & Measurement team. You will build reusable, scalable data-science solutions that drive commercial decisions and business growth.

Work with Python, PyTorch, Scikit-learn, Hugging Face, MLFlow, AzureML, and CI/CD/MLOps tools like Azure DevOps, Docker, and Kubernetes. The Applied AI team builds production LLM-powered systems, agentic AI, and ML pipelines for Glasswall’s cybersecurity solutions. No team size is stated.

Tech Lead role at a boutique financial services consultancy building digital banking solutions. Leads a team of engineers using Java, Kotlin, Python, JavaScript/TypeScript, Spring, and Node.js, with hands-on coding, system architecture, and cloud-based applications.