This Full Stack Engineering Lead role at Citi’s Finance Technology team involves hands-on development with Java, Spring Boot, Spring Cloud, React, TypeScript, Node.js, and microservices. The team is re-platforming applications to support the Finance business, focusing on building scalable solutions for regulatory and operational needs. Testing practices use Jest, Cypress, JUnit, and Mockito, with AWS or GCP experience as a plus.

React Native developer will work with JavaScript/TypeScript, APIs, and CI/CD to build and optimise mobile apps for iOS and Android. The role is with a FinTech undergoing a digital transformation programme, modernising core mobile products and improving user journeys.

Work with Microsoft Copilot Studio, Python, Azure, APIs, AI agents, LLMs, and generative AI to build AI-powered tools, automation workflows, and scalable solutions deployed into live business environments within a growing AI and Automation function.

Senior Software Engineer for pricing and availability systems on a global travel and e-commerce platform, using TypeScript, Node.js, C#/.NET or Python, and SQL. Work involves building pricing, quote-caching and availability services, resilient APIs, and improving performance and observability with tools like Datadog and Terraform.

Senior Kotlin backend role with full-stack exposure to Angular/React, Spring AI, reactive streams, and event-driven tools like Kafka or RabbitMQ. You'll build a data integration platform for banks, an open-source schema language, and a greenfield AI agent for autonomous orchestration.

You will architect low-latency inference pipelines for multimodal LLMs, TTS, and Vision models using C/C++, Python, PyTorch or JAX, and optimize them with custom CUDA/Triton kernels, TensorRT, and ONNX. The team at this seed-stage AI-native game studio builds intelligent virtual actors that speak, move, and react in real-time for interactive entertainment.

You'll work with Python, C++, Java, or Rust. The company builds security technology that combines AI, data and software to help organisations make better decisions in complex environments. You'll work directly with customers to build and deploy solutions.

Work with Python, AWS, and Kubernetes to build and maintain custom integrations, API fixes, and SDKs for a voice AI startup. You will support the Forward Deployed Engineering team, managing one-off integrations, platform fixes, and custom builds for enterprise clients deploying large-scale voice infrastructure.

Build features across a Svelte/TypeScript front end and Python back end using FastAPI, Django, PostgreSQL, and AWS. Tab is a YC-backed London travel fintech processing thousands of real-time payments per hour for over 100,000 global tourism businesses in 100+ currencies.

You'll work with Python, FastAPI, TypeScript, React, and GCP, orchestrating foundation models and data pipelines. Electric Twin builds a behavioral simulation platform that creates "digital twins" of populations to predict human behavior. You'll join a team of 17 shaping engineering culture and owning complex systems end-to-end.

Relay Technologies★2.0 (9)· London

Work with Python, Rust, TypeScript, Flutter, GCP, BigQuery, Cloud Run, ML modelling and LLM inference on a logistics platform reshaping goods movement. You will own end-to-end problems from routing algorithms to real-time optimisation and operational tools.

You’ll build core MRO systems using FastAPI, TypeScript, React, and LLMs—designing voice interfaces, workflow orchestration, and AI agents for aircraft maintenance. Fleetcraft is a London aerospace startup modernizing technician systems for hangar-floor reliability in a regulated FAA/EASA environment.

You'll build production-ready patent-generation algorithms and evaluation pipelines using Python, LLMs, prompt engineering, OpenAI evals, PostgreSQL, and React/TypeScript. The company is an AI startup transforming intellectual property for global IP teams and law firms. As founding AI engineer, you'll work directly with PhD founders.

You will work with Python, post-training language models (RL, distillation), and build data pipelines and inference infrastructure. The company is building a Societal World Model to simulate human opinion and influence, enabling Fortune 500 organizations to test strategies against simulated populations.

Use Python (FastAPI/Django) and Svelte with TypeScript to build and scale a payments platform processing 100 currencies and a discovery engine listing 100,000+ tourism businesses. Work on AWS cloud infrastructure and real-time transaction processing as part of a profitable, lean team of nine.