Build REST and GraphQL APIs and MCP servers in Python (FastAPI, Flask) to expose ML models from Databricks to internal apps, CRM platforms, and AI agents at RBC. Work within the Data Science team to architect the serving layer, handling contract design, authentication, and documentation.

You'll work with JavaScript, Node.js, Express, React, and MongoDB/Mongoose to set technical direction and oversee AI-assisted content-creation features. As Fractional Head of Product at StoryTerrace, you'll own the roadmap for two B2C platforms—an established product and a new self-serve app—directing one Full Stack Developer and advising on hiring. This role reports to the CEO and requires hands-on coding experience to unblock development.

Rocketlane seeks a Customer Engagement Manager to own end-to-end delivery of complex enterprise implementations, working with REST APIs, webhooks, OAuth, SAML, SSO, NetSuite, Salesforce, Workday, SAP, and iPaaS platforms like Workato and Boomi. The role leads 3–5 concurrent enterprise accounts through kickoff to go-live, designing integrations and driving project governance for a SaaS company focused on customer onboarding and professional services automation.

Sunlighten UK & Europe★2.0 (1)· London

You’ll work with Five9 (or comparable contact-center platforms), Salesforce Sales/Service Cloud, REST APIs, Zapier, and possibly JavaScript, Python, or .NET to build IVR, dialer, lead-routing, live-chat, and SMS integrations. The role owns Sunlighten’s UK omnichannel customer-engagement platform, connecting customers with Sales and Customer Care across voice, digital, and messaging channels. No team size is stated.

Cognizant★3.8 (17k)· London

You will work with Python (FastAPI or Flask) in a serverless architecture, integrating with a NextJS/React frontend and third-party APIs. You will help build and enhance the NHS Digital Onboarding Service (DOS) for the NHS API Platform.

Meta★4.0 (1.1k)· London

Work with languages such as C++, Java, Swift, Kotlin, Python, JavaScript, and Hack to build and optimize user-facing applications across mobile and web. As a member of Meta’s product engineering teams, you’ll help advance its platforms—Facebook, Instagram, WhatsApp, and immersive AR/VR experiences—that connect billions globally.

You'll work with Java/JVM and Spring on the backend, React/JavaScript/TypeScript on the frontend, plus CI/CD, distributed systems, and relational/non-relational databases. You'll join Wise's Account Integrity team, building fraud-prevention and financial-crime detection systems to protect customer accounts. Wise is a global technology company for moving and managing money.

Sainsbury’s★3.5 (16k)· London

You will build and integrate server‑side logic for the Multichannel Messaging Hub, using Node.js, TypeScript, microservices, REST/JSON/SOAP APIs, Kafka, Snowflake, AWS serverless services, Kubernetes, and Terraform. The team of 7 engineers owns cross‑channel campaign delivery for Sainsbury’s brands.

Standard Chartered★4.1 (3.3k)· London

Senior developer role on Standard Chartered’s Blade platform (in-house pricing, execution, and trade processing) using JavaScript, TypeScript, React, Redux, RxJS, Webpack, CSS, HTML, Azure DevOps CI/CD, and preferably Java backend.

You will build and maintain server-side applications and APIs using Node.js, Python, Java, C#, PHP, and Ruby on Rails, working with MySQL, PostgreSQL, MongoDB, and cloud platforms AWS and Azure. You will join the development team to design scalable backend systems for the company’s web platforms, collaborating with front-end developers using Angular and React.

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 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.

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

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.

Work with Java/Spring, React, JavaScript/TypeScript, CI/CD pipelines, and distributed systems. You'll join the Account Integrity team building a globally scalable fraud prevention engine to protect customer accounts and prevent financial crime using machine learning and real-time monitoring.

Design, develop and support D365 solutions across Power Platform and Dataverse, using C#, JavaScript, Power Automate, Power BI, and Power Apps. The role supports a major transformation programme, enhancing business processes and driving Dynamics adoption across the organisation.

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.

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.

Use object-oriented programming (Java or C#), Salesforce Lightning, Force.com, Apex, SOQL, JavaScript, Git, Jira, IntelliJ, CI/CD, and Salesforce REST APIs. Hackajob Ltd is a platform that connects developers with job opportunities. This Salesforce Developer role delivers complex business and technical requirements on the Force.com platform.

Hudson River Trading★4.5 (2)· London

You will write and maintain critical trading infrastructure using C/C++ or Python on Linux, working closely with engineers who design trading algorithms in a fast-paced, real-time environment. The role is with Hudson River Trading, a firm that brings a scientific approach to trading financial products.

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.

RELX Group★3.8 (133)· London

You will work with Java/J2EE, JavaScript, JSP, C/C++, HTML, XML, SQL, Windows, UNIX, and .Net. The team supports products for education electronic health records that introduce students to digital charting and prepare them for clinical documentation.

Elsevier★3.8 (769)· London

Work with Java/J2EE, JavaScript, JSP, C/C++, HTML, XML, SQL, Windows, UNIX, .Net, and various data storage subsystems. You'll develop complex software solutions supporting educational electronic health record products that prepare students for digital charting in clinical environments.

Wise★3.5 (42)· London

You will build and refine financial crime prevention systems using Java (or JVM languages) with Spring, React/JavaScript/TypeScript, and CI/CD pipelines, working 80% backend and 20% frontend. You join the Account Integrity team, which protects Wise’s global platform against fraud via machine learning and real-time transaction monitoring, and you will own projects end-to-end.

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.