You will work with Python, AI coding agents (e.g., Claude Code, Codex), and potentially AWS, Kubernetes, and Temporal. Unitary builds Virtual Agents — AI-powered software workers that automate complex workflows end-to-end in customer tools, focusing on commercial insurance, marketplaces, and primary healthcare.

You'll work with Python, building and deploying LLM-powered systems from scratch. As one of the first technical hires, you'll design and shape AI systems that solve a real-world problem, collaborating directly with the founding team.

You'll work with Python and/or TypeScript, using full-stack JavaScript or backend Python. The role is a founding engineer at a stealth AI company backed by a £100M bootstrapped founder with three successful exits.

Unity★3.5 (46)· London

Work with Unity’s early-stage Developer Data Framework, Diagnostics, IAP, Webshop, and D2C solutions, engaging mobile developers and studios across EMEA. You will bridge customer feedback to product, engineering, ads, and marketing teams, building go-to-market motions from scratch for emerging monetization and audience growth tools.

Build and own the machine learning models (propensity, uplift, contact strategy) that decide who, when, how often, and on which channel (voice, WhatsApp, email, SMS) Murphy's AI agents contact debtors to maximize recovery within legal limits. Work in Python, TypeScript, AWS, and PostgreSQL; design, run, and ship A/B tests and bandits on live traffic.

You'll work with JavaScript, TypeScript, React, HTML5, CSS, and server-side rendering to build production web applications and responsive interfaces. As a founding engineer at Hyre AI Limited, you'll shape the frontend architecture from an early stage.

Intercom★3.5 (4)· London

You will lead product engineering teams building Fin’s Customer Agent, a single AI agent that works across support

Build a new category of SaaS using React on the frontend and Python with Django, Flask or FastAPI on the backend, with cloud technologies desirable. The company uses AI and machine learning to help businesses predict revenue, drive customer loyalty, and capture value from existing customers.

Lead Front-End Developer with React and TypeScript, working on payment and point-of-sale technology for live events. Responsible for front-end architecture, design system, shared component library, payment flows, and real-time data integrations. Will mentor a small team and own tooling, standards, and CI/CD release pipelines.

You will work with JavaScript/TypeScript, SQL/NoSQL databases, and cloud infrastructure across frontend, backend, data pipelines, and APIs. The team builds an AI-powered investment platform for retail investors to create, backtest, and automate personalized strategies. The FCA-authorised company also integrates with financial data, payments, and custody platforms.

You will build Python (Prefect) backends, React frontends, and core ML systems, including agentic AI features and evaluation pipelines. The platform prioritizes cybersecurity threats using real-world attacker logic to focus on exploitable attack paths.

You will use Python or JavaScript with low-code platforms like Zapier or n8n and integrate LLMs and AI via REST APIs. You will identify and automate manual inefficiencies across the business, building internal automation ecosystems at Goodlord, a platform used by around 3,000 letting agents.

You'll work with Python, SQL, Airflow, PyTorch, Spark, AWS, and ML Ops tools to build and ship production-grade machine learning models. The team creates the intelligence layer behind a UK on-demand labour platform, forecasting demand and matching workers to shifts.

Use computational chemistry tools, Python (PyTorch, ASE, RDKit), and APIs to build technical resources for CuspAI's AI platform that accelerates materials discovery for energy, carbon capture, and semiconductors. This role also provides scientific advisory and leads workshops for enterprise and research partners.

Work with Python, PyTorch, JAX and time-series modelling to build and deploy physics-informed machine learning models. You will design, train and deploy models for complex industrial operational systems, working with sparse and noisy real-world data as an early ML hire at a company building AI for manufacturing.

You will own an existing production React/TypeScript application across web, iOS, and Android, integrating with Python/FastAPI backends and managing CI/CD pipelines. The team builds a computer-vision platform that turns video data into actionable insights. You will drive frontend architecture on a small, collaborative engineering team.

Build scalable backend services, APIs, and cloud-native systems on AWS running Kubernetes, using TypeScript, Node.js, Docker, and React. You will work directly alongside AI Engineers to build the production platform behind their next-generation AI authentication product.

You’ll work with SQL, Snowflake, dbt, Fivetran, and Claude to build the analytical foundation for Lendable’s US Loans team. You will own and improve data models supporting lending decisions, pricing, portfolio analysis, and investor reporting, and drive dbt model development to streamline insight generation.

Work with C#, Python, TypeScript, or JavaScript; APIs; databases; and Git. Build features across the frontend and backend for JivPad, an AI-powered communication platform providing real-time call assistance and in-person language translation.

You'll work with SQL, Snowflake, dbt, Fivetran and Claude to build the analytical foundation for Lendable's US Loans team, improving how data is structured, transformed, and consumed with analysts, product teams, and engineers.

You will build frontend applications using React and TypeScript, develop reusable UI components, and work on real-time features with WebSockets and GraphQL. The company builds a suite of real-time products for enterprise customers in specialized financial markets. The small, experienced engineering team offers significant ownership from day one.

Zencargo★1.8 (6)· London

Works with TypeScript, Python, Kotlin, AI-assisted development tools, APIs, webhooks, databases, n8n, LLM apps, cloud infrastructure, Terraform, and CI/CD. Embeds with operations teams to automate freight and supply-chain workflows, replacing manual processes with software and AI-driven solutions. Integrates with internal Zencargo services, carrier platforms, and third-party APIs.

You'll work with TypeScript and AI/LLM systems to build an AI-powered legal tech product transforming UK conveyancing, a currently manual £2.5 billion market plagued by delays and failed transactions. As a Staff Product Engineer on a small, early-stage team, you'll shape product direction, define requirements with users, and ship features quickly while owning outcomes end-to-end.

You will work with TypeScript, Python, Kotlin, APIs, webhooks, databases, event-driven workflows, AI-assisted tools, n8n, LLM apps, and cloud infrastructure. This role embeds with operations teams to solve freight logistics problems by turning manual workflows into automated, AI-handled platform logic.

You will build frontend applications with React, TypeScript, JavaScript (ES6+), GraphQL/Apollo, Material UI, and WebSockets. This is for an early-stage company creating a real-time platform for enterprise financial markets, where you will own features alongside product and backend engineers. The team is small and experienced.