7 api developer jobs found in London

Mid-Level .NET / Full Stack Developer – Hybrid – £450/day Outside IR35 | C# | Azure | Event-Driven Systems | Payments | API-Driven We have a great opportunity for a Mid-Level .NET / Full Stack Developer to join a growing payments company. As a .NET Developer , you’ll be working as part of an experienced engineering team building and scaling a high-throughput payments platform. The business is entering its next phase of growth, launching new products, enabling new partner integrations, and expanding a platform that already powers multiple live financial services products used globally. You’ll be contributing to a modern, cloud-native platform built with .NET and Azure , designed around API-first architecture and event-driven microservices . The platform supports complex payment flows, partner integrations, and high-volume transaction processing. This is a hands-on development role where you’ll work closely with senior engineers to deliver reliable, scalable...

.Net 6, .Net 10, C#, ASP.NET, .NET Core, AWS, CDK, IaC, Cognito, S3, KMS, CI/CD, Docker, Containers, Entity, Firebase 3-month contract role. Outside IR35. £500 per day. Must be a UK based candidate. No visa sponsorship or visa transfer. Experience within Healthcare, Pharma or LifeSciences is a definite advantage. The role will involve the following: Migrate the platform to .NET 10 LTS Implement secrets management using AWS Secrets Manager Strengthen authentication and authorisation mechanisms Enhance audit trail and compliance features for healthcare regulations Improve API security, including rate limiting and CORS configuration Update Docker containers and CI/CD pipelines Establish and expand unit and integration test coverage Work with Clean Architecture patterns across the solution To start ASAP. Please email a CV to Roger at Jump IT in the first instance.

Boomi Integration Developer - Contract Overview We are looking for an experienced Boomi Integration Developer to support a series of integration projects. This is a 3‑month contract, fully remote, and operating outside IR35. Key Responsibilities * Design, develop, and maintain integrations using the Boomi platform * Work closely with internal teams to understand integration requirements * Troubleshoot and optimise existing Boomi processes * Support project delivery across multiple systems and data sources * Ensure best practice, documentation, and smooth handover at the end of the engagement Requirements * Proven experience as a Boomi Integration Developer * Strong understanding of integration patterns and API development * Ability to work independently and deliver in a fast‑paced environment * Excellent communication and problem‑solving skills * Boomi certifications beneficial but not essential Contract Details * Length: 3 months * Location: Remote * IR35 Status: Outside IR35...

Boomi Integration Developer - Contract Overview We are looking for an experienced Boomi Integration Developer to support a series of integration projects. This is a 3-month contract, fully remote, and operating outside IR35. Key Responsibilities * Design, develop, and maintain integrations using the Boomi platform * Work closely with internal teams to understand integration requirements * Troubleshoot and optimise existing Boomi processes * Support project delivery across multiple systems and data sources * Ensure best practice, documentation, and smooth handover at the end of the engagement Requirements * Proven experience as a Boomi Integration Developer * Strong understanding of integration patterns and API development * Ability to work independently and deliver in a fast-paced environment * Excellent communication and problem-solving skills * Boomi certifications beneficial but not essential Contract Details * Length: 3 months * Location: Remote * IR35 Status: Outside IR35...

Overview We are seeking a Senior Python Developer to support a large-scale digital transformation programme. The role focuses on building reliable Back End services, improving system performance, and contributing to a modern, scalable engineering environment. The client is open to strong EU-based talent. Role Detail: Contract Length: 3-6 months Rate: £250-400/day Outside IR35 (Depending on experience) Work Model: Fully Remote Key Skills and Experience Strong commercial experience with Python (Django) Solid understanding of REST APIs , microservices, and Back End architecture. Experience with cloud environments (AWS & Azure). Familiarity with CI/CD pipelines and modern DevOps practices. Strong understanding of relational and/or PostgreSQL. Ability to work in distributed teams and communicate clearly. Experience with Typescript and Svelte Good problem-solving skills and attention to detail. Nice to Have Experience with containerisation (Docker,...

AI Engineer (Contract) – £500/day Outside IR35 📍 Canary Wharf, London (3 days onsite) 🇬🇧 UK-based applicants only We’re looking for experienced AI Engineers who think holistically, automate relentlessly, and know how to turn modern AI capabilities into production-grade, high-impact applications . Our AI organisation is building real-world AI products that deliver business value at speed. This role is ideal for seasoned engineers who combine strong software engineering fundamentals with a pragmatic, hands-on approach to AI tooling and infrastructure. What you’ll be doing Designing, building, and maintaining production-grade AI applications using modern engineering practices (CI/CD, testing, observability, cloud-native design). Developing reusable AI platforms and tools (e.g. conversational bots, AI-powered search, unstructured data processing, GenAI solutions). Working in cross-functional, embedded teams with business stakeholders to rapidly deliver...

React Developer Remote with very occasional client visits £400pd to £440pd (dependent on experience) - Outside IR35 3 - 6 month contract Our client, an established and successful Consultancy are looking for a number of senior and mid-level Developers to join them on a contract basis With head offices in the north of the UK and branches spreading across the globe, they're a dynamic technology consultancy leader with a dedicated team of professionals, partnering with sector leaders After recently winning a large public sector project they are creating a whole new team and need people who are able to start no later than March 2nd. This is a fully hands on role where you will work as part of an established successful team, primarily working with React and Typescript technologies We are looking for: Expert knowledge of React Strong proficiency in JavaScript (ES6+), HTML5, CSS3, and responsive UI engineering. Experience with Redux or other state management libraries....