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 will build and evolve customer-facing interfaces for AI Virtual Agents using React, TypeScript, Next.js and Vite, and refactor the frontend into a scalable platform with a shared component library and design system. Unitary’s factory builds custom operations agents that complete complex workflows end-to-end in customer tools.

Build a production platform using FastAPI, React, GCP, PostgreSQL, Docker, Terraform, and Redis, developing agentic AI systems and evaluations for automated cyberattack investigations. You'll own reliability end-to-end, including CI/CD, SLOs, and incident response. This is a founding role at an AI-native Digital Forensics and Incident Response startup.

You will develop and iterate on polymer blends and additive packages using characterization tools such as DSC, TGA, and rheometry. You’ll join a climate tech team creating high-performance, compostable plastic alternatives, bridging lab characterization and industrial scale-up. The startup is well-funded at Series A, backed by leading impact investors.

You'll work with time-series data, supervised and unsupervised ML, CI/CD, version control, and tools like Claude Code, MLflow, and cloud platforms (Azure, AWS, GCP) with MongoDB. Ceto provides operational intelligence for maritime, analyzing ship data to predict mechanical failures through anomaly detection and degradation forecasting.

You'll work with AI-assisted development tools like Claude Code, LLMs, RAG, agentic tooling, and own the full stack: React/Angular, Python, AWS/Terraform. Embedded with Product and Engineering teams, you'll design and build bespoke AI solutions for customers at a hypergrowth SaaS scaleup, turning their workflows into reusable, production features.

You will work with Python, TypeScript, LLMs, agentic workflows, Claude, Claude Code, MCP, and APIs. The company’s live AI product is a step change for a UK industry; you’ll build systems that power the commercial team’s sales and marketing automation. This is an early-stage AI-native startup with a revenue-generating product and an enterprise pilot.

You will build multi-agent AI systems using LangGraph, Neo4j knowledge graphs, FastAPI, and Google Cloud Platform. The role focuses on architecting and scaling AI-native software for tax advisory teams at a seed-stage London startup.

You will work with React and MUI to design and implement interfaces for visualizing attack chains and hierarchical vulnerability data. As the founding design hire, you’ll build the intelligence layer for cybersecurity, turning complex vulnerability data into intuitive threat models for a well-funded cybersecurity AI startup.

Lovable★4.0 (43)· London

Uses Go, Rust, TypeScript; AWS, Azure, Google Cloud, Cloudflare; Kubernetes, Terraform, Temporal, OTEL, CI/CD; PostgreSQL, ClickHouse, Firestore, Spanner, BigQuery. Builds the platform for Lovable Enterprise enabling secure, cloud-agnostic deployment, defining architecture for sandboxing, networking, encryption, identity, and mentoring engineers.

This role leads cybersecurity and internal systems for AIOS, which builds the world’s first full-stack AI doctor. You will own security strategy, identity and access management, endpoint security, incident response, and compliance with frameworks like HIPAA, GDPR, SOC 2, and ISO 27001, working across the company's healthcare, technology, and pharmacy platforms.

As the first software hire, you will build the entire cloud and platform layer, working with connected hardware, real-time data, and external energy markets. NODI Energy is a YC-backed startup orchestrating plug-in batteries as a flexible power fleet to cut grid congestion and free up capacity for data centres.

You will work with Python, LLMs, symbolic AI, knowledge graphs, decision trees, and propositional graphs in a monorepo, building high-performance systems. The team of 40 is transitioning from bespoke enterprise solutions to a scalable AI platform that combines neurosymbolic technology with deterministic reasoning for financial and accounting clients.

Build a high-scale SaaS platform using Rust on the backend and React/TypeScript on the frontend, hosted on Google Cloud. Platformed Ltd automates audit and control assurance workflows for enterprise clients. As the seventh engineering hire, you will own features end-to-end, from architecture to deployment.

Build and iterate on full-stack product surfaces and core infrastructure using modern AI tools, LLM orchestration, and multi-step reasoning systems. You will work directly with founders at a stealth-stage fintech that builds an AI-native observation layer for institutional investors.

Lead a software team building MasterBuilder, a platform orchestrating robotic home construction using Node.js, TypeScript, React, and Three.js. The company automates homebuilding via robotic MicroFactories that produce timber structures on-demand.

You will own back-end infrastructure and data strategy, building scalable GCP pipelines, designing high-performance APIs with Python and FastAPI, and developing full-stack features with automated CI/CD. The company, an Imperial College spin-out, produces advanced gas sensors and AI that predict food freshness in real-time to replace printed expiry dates across global supply chains.

You will develop and refine LLM agents, working with agent scaffolding and internal benchmarks. Mantic builds AI systems that outperform human superforecasters in predicting geopolitical, economic, and technological events.

You will build and ship polished, full-stack features using AI tools to accelerate development, owning the entire product lifecycle from customer interviews to deployment. You will join an 8-person team at Romeai, a London startup creating an AI-driven real-time system of record for global supply chains.

You’ll build the automated outbound engine from zero to one, owning CRM workflows, data enrichment pipelines, and sequencing, using Python, SQL, JavaScript, and modern AI tools. This founding role drives global revenue growth for a VC-backed AI proptech startup, deploying AI agents to real estate decision-makers.

Use Python, FastAPI, Postgres, Redis, Docker/Kubernetes, and AWS to design and deploy high-performance APIs and backend services for electronic commodity trading platforms as a founding member of the company's new London engineering hub.

You will work with Python, TypeScript, AWS, PostgreSQL, event-driven and distributed systems, and CI/CD. The company is building a new real-time platform that combines data, hardware, AI, and energy trading to make the electricity grid cleaner and more intelligent. This is a backend-first role on a small engineering team.

You will work with React, Next.js, Node, Python, Supabase, Firebase, Postgres, and AI tools like Copilot to build and ship web applications, backend services, APIs, and manage databases for a modular fan engagement platform serving sports rights holders, brands, and influencers.

You'll work with TypeScript, Fastify, React, Postgres, and Temporal. This pre-seed startup is building an operating system for financial compliance, automating statutory audit end-to-end for regulated markets. As a Founding Engineer, you'll own the agent layer that plans, executes, and checks audit work.

You will work across the full application stack—API design, data modeling, and front-end interfaces—integrating with legacy enterprise systems like ERPs and TMS. This company builds the orchestration layer for global supply chains, tackling coordination across suppliers and factories. You join a team of eight as one of the first Product Engineers in a new London office.