Citi★3.9 (21k)· London

You will work with TypeScript, React, HTML5, CSS, JavaScript (ES6+), Chromium/Electron/OpenFin, FDC3, REST/WebSocket APIs, Kafka/Solace/Tibco, and CI/CD with Jenkins. The team delivers pricing solutions and trading GUIs for Citi’s Foreign Exchange business. You will provide technical leadership, mentor junior engineers, and drive AI integration.

You'll build GTM systems using HubSpot, DealHub, Gong, Clay, APIs, webhooks, Python, JS, SQL, and AI tools (ChatGPT, Claude, Copilot, Gemini, Notion AI). This role designs end-to-end systems—from lead enrichment and routing to quote-to-cash—for Monta’s EV charging platform, including prototyping AI agent workflows.

You’ll build customer-facing treasury software using **Python, React and TypeScript**. You’ll own features end to end for TreasurySpring’s Fixed-Term Fund platform, which replaces manual cash-management processes and legacy systems for institutions.

Build features across a dual-stack backend (TypeScript, C#, .NET) and microfrontend React apps, using AWS (ECS, Lambda, SQS, DynamoDB, DocumentDB), Terraform, SST, and AI coding agents. You'll evolve a B2B SaaS platform that powers UK housing transactions, adding new AI capabilities alongside a mature .NET foundation.

You will build scalable server-side logic using JavaScript, TypeScript, and Node.js in a microservices architecture on AWS with Kubernetes, Terraform, Kafka, and Snowflake. You will join the MMH team within the Martech domain, which orchestrates campaign delivery across email, push notifications, and personalised content for all Sainsbury’s Group brands. The team includes 7 engineers.

Lead Software Engineer for the PRIIP Cloud platform, owning full-stack development with TypeScript/Node.js, React, Java/Kotlin, REST APIs, event-driven architectures, AWS, Docker, and Kubernetes. The team builds a cloud-based PRIIP documentation and reporting system for regulated financial services, collaborating with compliance, quant, and product specialists. This role leads a multidisciplinary team of engineers and subject matter experts.

Develop backend services using Node.js, Python, Java, C#, PHP, and Ruby on Rails, with databases including MySQL,

TypeScript, React, Node.js, Bun, Kubernetes, and AWS. The team builds web apps, back-office systems, and tooling for financial product comparison across money.co.uk, Uswitch, and Confused. As a Staff Software Engineer, you set technical direction for Financial Services.

You will work with JavaScript (TypeScript), React, Redux, RX JS, NPM/Yarn, webpack, CSS, HTML, Azure DevOps CI/CD, and Java. As a senior developer on the FM Digital Channels team, you will build Blade, the bank's strategic in-house pricing, execution, and trade processing platform for Financial Markets.

Lead Python Developer role using Core Python, Flask, VueJS, JavaScript, CSS, HTML, SQL, AWS, Terraform, Docker, and serverless components, with CI/CD and Agile practices. The developer builds, enhances, and supports production applications within UK public sector programmes, collaborating with delivery, product, and data teams.

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.

BNY★3.5 (5.5k)· London

You'll use Java 17/21 with Spring, Maven, Groovy, JavaScript/TypeScript (Angular), Docker, GitLab CI/CD, IntelliJ, Windsurf, Splunk, and AppDynamics to build secure backend services, batches, and APIs for a global financial services company.

Zoopla★3.9 (18)· London

A 12-month maternity cover role on a dual-stack C#, .NET, and TypeScript backend with React microfrontends, using AWS managed services (ECS/Fargate, Lambda, SQS, DynamoDB, DocumentDB) and Terraform/SST. You'll build B2B SaaS software for estate agents and home builders at Alto Software Group. Take end-to-end ownership of features from design to production, working with the product team and AI coding agents.

You'll work primarily with TypeScript, Node.js, and PostgreSQL on GCP, designing and building scalable backend systems. The team develops and maintains a robust investment platform that powers features like mutual funds, bonds, and family investment tools.

You'll work across the full stack using Python, frontend, embedded systems, ML, and networking, with Linux, devops, and edge-device deployment. Minerva Defence builds software, hardware, and networking for unmanned battlefield systems.

Work with Java, Python, JavaScript/TypeScript, Go, cloud platforms (AWS, Azure, GCP), CI/CD pipelines, and version control. Guiding the technical direction of BabuSpace’s premium short-term rental marketplace platform for African cities, designing backend architectures, and mentoring engineers.

Build enterprise-grade web applications using Python (Django/FastAPI), React, TypeScript, and PostgreSQL. Develop RESTful APIs, responsive UI components, and contribute to system design, CI/CD pipelines, and performance optimization.

You’ll work with Python (Django/FastAPI), React, TypeScript, PostgreSQL, REST APIs, and CI/CD. You’ll own end-to-end feature delivery on scalable, enterprise-grade web applications.

Build high-performance front ends with React, TypeScript, JavaScript, React Hooks, and ES6/ES7 for a leading HFT firm in London. The role focuses on UI engineering within a trading environment.

Java and Spring Boot, React, AWS, and CI/CD pipelines are the primary technologies. You will build microservices-based customer-facing applications for a leading retail bank’s cloud-native digital banking platform. No team size is stated.

Work with Kotlin, Java, Spring Boot, microservices, REST APIs, Node.js, TypeScript, Express.js, Nunjucks, AWS/Azure/GCP, Docker, Kubernetes, Terraform, and CI/CD tools. You'll build secure, scalable digital services on large-scale transformation programmes for the Public Sector and Healthcare within Agile, multidisciplinary teams. Mentoring other engineers is expected.

Full Stack Developer role at a specialist investment business. You'll use TypeScript, JavaScript, Python, React, Next.js, Node.js, RESTful APIs, relational/NoSQL databases, Azure, Git, and CI/CD to build and evolve the technology platform with the existing team and senior stakeholders.

You'll work across the full stack with TypeScript, React, and Python, building a continuous AI-auditing platform for safe and responsible AI deployment in HR tech. As an early product engineering hire at a 5-person startup (growing to 10 by mid-2026), you’ll own product features end-to-end reporting to the CTO.

Deloitte★3.9 (14k)· London

You will use Figma, React, TypeScript, and HTML/CSS to design and front-end code AI-powered agentic experiences, including conversational interfaces and agent-orchestration workflows for clients. The team reimagines how users interact with intelligent platforms, developing trust-centered, multi-step AI interactions. You will manage design workstreams and mentor junior designers and front-end developers.

You'll work across the full stack—backend distributed systems, cloud with IaC, and data pipelines including vector stores—using tools like Claude Code and AI agents for code review, refactoring, and parallel work. This Principal Engineer role on a large iGaming engagement oversees sportsbook, casino, and gaming platforms for a major client, managing a group of engineers and Tech Leads as the named delivery owner. The team includes engineers and Tech Leads that you directly line manage.