12 api developer jobs found

Senior .NET / Full Stack Developer – Hybrid – £600/day Outside IR35 | C# | Azure | Event-Driven Systems | Payments | API-Driven We have a unique opportunity for a Senior .NET / Full Stack Developer to join a payments company. As a Senior .NET / Full Stack Developer , you’ll play a key role in building and scaling a high-throughput payments platform as the business enters its next phase of growth. This includes launching new products, enabling new partner integrations, and expanding a platform that already powers multiple live financial services products used globally. You’ll be building on top of 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 senior engineering role where you’ll contribute to architectural discussions, drive engineering best...

Software Engineer - Golang - Go - Product - TDD - £520/£550 (Outside IR35) - Hybrid - 3 months - Immediate Starter Paying up to £550 per day (Outside IR35) We're a mission-driven tech company that builds products to help people make confident decisions about their finances and everyday services. They are looking for a strong Go Developer who is excited about working with new technologies. Essential Skills: Strong commercial experience with Golang Must have a Product first mentality Experience with observability would be great Experience configuring, deploying, and monitoring applications on AWS. TDD (Test-Driven Development) experience. API build experience is essential, especially with 3rd party API's Comfortable working with relational and NoSQL databases, including complex queries and performance optimization. Solid understanding of web design patterns, including SOLID principles. Experience working in an agile, collaborative environment. Familiarity with...

ComfyUI Workflow Developer | London | Remote-Friendly | £500 - £600 We're working with a high-end creative agency specializing in hyper-realistic CGI for global luxury brands on this exciting opportunity. We are looking for a technical visionary to bridge the gap between AI experimentation and high-end production pipelines . This role is about more than just generating pretty images; it’s about engineering robust, scalable AI architectures using ComfyUI, Python, and Stable Diffusion to meet the exacting standards of the luxury market. You will move from a high-impact POC sprint into a full-scale production deployment, automating asset generation that rivals traditional CG I. The R ole• Architect and build advanced ComfyUI workflows capable of generating high-resolution, brand-compliant assets at sca le.• Develop custom Python scripts and API integrations to connect AI pipelines with existing Digital Asset Management (DAM) syste ms.• Transition from a 4-week...

Java Developer - SC Cleared Location: London (1–2 days onsite per month) Contract: Outside IR35 Rate: £600–£675 per day Duration: 12 Month Contract Start: Immediate / Short Notice Preferred Eligibility: Active SC Clearance required (DV clearance ideally) Overview An experienced Java Developer is required to build and maintain scalable, high-performance applications within a secure public sector environment. Requirements Strong experience with Java & Springboot Solid Java back-end development experience Experience working in public sector Strong understanding of API integration and system design Active SC Clearance required (DV clearance ideally)

Java Developer - SC Cleared Location: London (1-2 days onsite per month) Contract: Outside IR35 Rate: £600-£675 per day Duration: 12 Month Contract Start: Immediate/Short Notice Preferred Eligibility: Active SC Clearance required (DV clearance ideally) Overview An experienced Java Developer is required to build and maintain scalable, high-performance applications within a secure public sector environment. Requirements Strong experience with Java & Springboot Solid Java Back End development experience Experience working in public sector Strong understanding of API integration and system design Active SC Clearance required (DV clearance ideally)

.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...

Position: App Developer Location: Vauxhall/Stratford Day Rate: £600 p.d Outside IR35 Must hold active DV clearance A central government department is looking for an experienced App Developer to join a high-security programme. This role requires working on-site 5 days per week in Vauxhall, moving later to Stratford later on in the project. Due to the nature of the work, candidates hold UKSV DV clearance. Key Skills & Experience Strong expertise in Python, Docker, Kubernetes, and Data Governance Experience working in air-gapped environments, including managing dependencies and build pipelines without Internet access Proven background building APIs for data enrichment services Orchestration & data pipeline experience with Prefect or Airflow, and K8s or Swarm Configuration and automation of business workflow tooling (eg, Jira) Hands-on experience with a range of databases and storage technologies: Elastic, Mongo, Cassandra, Redis, S3 Desirable Skills...

Position: App Developer Location: Vauxhall / Stratford Day Rate: £600 p.d Outside IR35 Must hold active DV clearance A central government department is looking for an experienced App Developer to join a high-security programme. This role requires working on-site 5 days per week in Vauxhall, moving later to Stratford later on in the project. Due to the nature of the work, candidates hold UKSV DV clearance. Key Skills & Experience Strong expertise in Python, Docker, Kubernetes, and Data Governance Experience working in air-gapped environments, including managing dependencies and build pipelines without internet access Proven background building APIs for data enrichment services Orchestration & data pipeline experience with Prefect or Airflow, and K8s or Swarm Configuration and automation of business workflow tooling (e.g., Jira) Hands-on experience with a range of databases and storage technologies: Elastic, Mongo, Cassandra, Redis, S3 Desirable Skills...

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...

Technical Program Manager - Platform/Data/Infrastructure Outside IR35 SOLE AGENT Location: London (5 days onsite) Our client, a leading global investment firm is seeking a senior Technical Program Manager to lead large-scale engineering programmes across data platforms, cloud infrastructure and internal developer platforms. You will sit at the centre of complex technology initiatives, working with senior engineering leaders to deliver critical platform capabilities used across the business. Your Skills Strong Technical Program Management background within complex engineering environments Experience delivering large cross-team software, platform or infrastructure programmes Technical fluency with system design, APIs, data flows and cloud platforms Strong stakeholder management with engineering leadership Ability to operate in fast-moving, technically complex organisations Types of Programmes Platform and infrastructure modernisation...