You’ll build cloud-native applications for a leading global financial institution, using Java with Spring Boot and React to support critical financial operations.

Full-stack Java development on Linux/Unix, using AI coding tools like Claude Code, Windsurf, Devin, or GitHub Copilot. The role is for Ascendion, a technology services company.

You will work with backend development, databases, APIs, cloud services and production machine learning systems. This is for a growing technology business. No specific project or team size is mentioned.

Citi★3.9 (21k)· London

Backend Java developer building the Citi Integrated Digital Assets Platform (CIDAP) using Java Spring, web3 libraries (Web3J/Web3JS), Solidity, and containerized DevOps tools (Git, Jenkins, Helm).

Citi★3.9 (21k)· London

You will work with Java, Spring, Web3J/Web3JS, Solidity, Docker, and Hardhat/Foundry to build Citi’s Integrated Digital Assets Platform (CIDAP), integrating blockchain networks and digital asset infrastructure.

Citi★3.9 (21k)· London

Work with Solidity, Web3J/Web3JS/Ethers.js/Viem, Java/Spring, Node.js, and blockchains such as Ethereum, Hyperledger Besu, Canton, and Solana, using Hardhat/Foundry/Truffle for testing. Contribute to Citi's Integrated Digital Assets Platform (CIDAP) building Web3 components for tokenization, smart contracts, and on-chain settlement.

Work with Python, FastAPI, Docker, DuckDB, JSON Schema and Git to design, build and ship client ETL pipelines that map raw bank data onto the FIRE regulatory reporting standard. You will maintain a shared ETL framework, write validated mapping code, and mentor junior engineers at Suade, a regtech SaaS company automating compliance for financial institutions.

Samsara★3.6 (32)· London

Samsara interns work on the Connected Operations Cloud, building backend infrastructure in Golang, web clients with TypeScript/React and GraphQL, mobile with React Native, or embedded software for IoT devices. Projects involve scaling data ingestion, real-time data processing, and creating actionable insights for industries like transportation and agriculture.

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.

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.

Lead the Integrations team connecting Yuno’s payment platform to PSPs and gateways globally. You’ll work with Java, Golang, Kotlin, SQL, microservices, event-driven architectures, APIs, and AI-assisted coding tools like Claude Code, shaping scalable, secure payment infrastructure.

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 will work with Python, LangGraph, CrewAI, OpenAI/Claude Agent SDKs, AWS Bedrock, ECS Fargate, Lambda, Step Functions, and LLMs like GPT, Claude, and Perplexity. You will design and evolve multi-agent systems and LLM pipelines powering a production-grade AI-powered brand analytics platform that helps businesses understand market positioning.

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.

JustPark★2.7 (6)· London

Build AI agents and tools using Claude Code and Codex, integrating with Asana, Jira, Salesforce, Slack, and Zendesk. This role automates workflows across commercial, marketing, finance, and operations teams at JustPark, a UK/US parking platform serving B2B and B2C clients.

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.

Senior Frontend Engineer working with JavaScript, React, Vue, and TypeScript on a HealthTech product for the care industry. The team of 10 builds software used within the NHS to assist doctors and nurses.

Houseful★0.0· London

A 12-month fullstack engineering cover role using TypeScript, C#, .NET, Node.js, and React on AWS (ECS/Fargate, Lambda, SQS, DynamoDB, DocumentDB) with Terraform. You will build microservices and microfrontends for a B2B SaaS platform powering UK housing transactions. You will also use AI coding agents and own features from prototype to production.

Build React Native identity-verification and onboarding experiences using JavaScript/TypeScript, component architecture, state management, and CI/CD pipelines. The identity engineering team owns the customer-facing front door of Zepz’s cross-border remittance platform, handling millions of users’ first contact and security checks.

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.

Google★4.3 (6.2k)· London

You'll develop in C++, Python, or Rust, building the Google Cloud Universal Ledger (GCUL), a cutting-edge payments platform addressing cost, speed, and fragmentation in financial systems. You'll implement low-latency features, including cryptography like homomorphic encryption and zero-knowledge proofs, while owning code for consensus, transaction dissemination, and finalisation.