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.

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 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.

Work with Python or Node on backend distributed systems and serverless architectures on AWS, with a smart contract language such as Solidity. The company builds services to accept card payments and grow businesses globally. No team scope is specified.

Harvey Nash★3.8 (49)· London

You will build enterprise-scale applications using Java, Spring Boot, microservices, and front-end technologies (likely React or Angular), with exposure to AI tools and modern DevOps practices. You will join a high-performing engineering team at Harvey Nash, developing large-scale software solutions in a hybrid London-based setting.

Senior Java Full Stack Developer building large-scale enterprise applications for a global financial services firm. You will work with Java and embrace AI-powered development on modern software engineering projects.

A Java Full Stack Developer role building enterprise software and embracing AI-powered development. You will work on large-scale enterprise applications within a global financial services organisation, using Java as the core technology.

Senior full-stack role designing and scaling cloud-native applications for a global investment bank’s risk management space. Technologies include Java, Kotlin, React, and AWS. Work involves end-to-end development alongside cross-functional engineering teams.

Work with Python and Django to develop and enhance web applications, supporting system integrations and delivering technology solutions for strategic business objectives as part of a collaborative digital team.

Work with Java, Spring, and AWS on a cross-functional, service-oriented team extending and maintaining Awin's Affiliate Marketing platform. You will design reliable services, write clean, well-tested code, and take ownership of meaningful engineering challenges.

You will work with Astro, Sanity, GROQ, Portable Text, TypeScript, HTML, CSS, Tailwind CSS v4, Figma, SSR, serverless/edge runtimes, SQL, and CI. You will co-own the component library, content model, and rendering stack for synthesia.io, the marketing website of the world’s leading AI video platform.

Principal Engineer role working with Python, AWS, and Kubernetes on an AI-powered FinTech platform that transforms data infrastructure and workflow automation for global financial markets. This first Principal hire will create technical solutions across teams and report to the VP of Engineering.

You will work with Python, AWS, Terraform, SLSA, in-toto, Sigstore, and SBOMs to design and build greenfield provenance systems that capture, validate, store, and expose software build traceability. The team creates next-generation supply chain trust infrastructure, giving organisations verifiable traceability from source code through every downstream environment.

Work with Java 17 & 21, microservices, event-driven architectures, Kafka, IBM MQ, AWS, Docker, Oracle SQL/PLSQL, Git, Jenkins, Jira, and RESTful APIs, with exposure to Golang or AI. You'll join a FinTech engineering team building scalable backend services and distributed applications in an agile environment.

Develop and enhance Acturis' global SaaS insurance platform using

SharkNinja★2.9 (146)· London

You’ll work with HTML, CSS, JavaScript/TypeScript, React or Vue, Git, Jira, Figma, and AI tools like Claude Enterprise, coding assistants, and automated testing. As a CodeShark, you’ll be embedded in SharkNinja’s D2C business, fixing website bugs and bridging Design and Engineering to improve consumer-facing sites. This is an early-career fixed-term role.

The API Platform team owns Perplexity's public-facing surface: the Search API, Agent API, SDKs, and docs. Engineers work in Go, Rust, and Python across cloud infrastructure, Kubernetes, and CI/CD, building agent-consumed surfaces like hosted MCP, tool calling, and auth flows while owning APIs end to end from RFC to production.

Ebury★3.3 (13)· London

Senior Software Engineer (Money Flows) at Ebury (London, hybrid) will work with Python, Django, FastAPI, PostgreSQL, Kafka, AWS, Kubernetes, Terraform, Jenkins, Prometheus, and Kibana. The role owns development, scalability and optimisation of the company’s multi-currency account systems, incoming funds, and outgoing payment processes on its core transactional platform. This is a global team spanning Europe and South America.