Senior MuleSoft Developer

Arm; City Of London; Hybrid; GBP 100,000 - 125,000; Full time

Job summary

A leading technology consultancy is seeking a Senior MuleSoft Developer for a 6-month contract based in London. The ideal candidate will have extensive experience with integration microservices and must demonstrate the ability to write clean code adhering to SOLID principles. Responsibilities include delivering maintainable code, managing API developments, and working within a collaborative team environment. This role requires current NPPV3 clearance and offers a hybrid working model, with three days in the office.

Responsibilities

• Deliver high-quality, maintainable code and development outcomes.
• Manage data exchange between backend services, front-end applications, and third-party APIs.
• Lead and contribute to technical user stories focused on integration and service optimisation.
• Document solutions using diagrams, flowcharts, and clear code comments.
• Ensure compliance with quality standards, including automated testing and code reviews.

Skills

Experience delivering integration microservices using MuleSoft best practices

Proven ability to write clean, maintainable code following SOLID principles

Designing RAML, REST APIs, flow control, and error handling

Hands-on experience with the Anypoint Platform

Securing and managing APIs using API Manager

Developing frameworks for error handling and logging

Managing the API development lifecycle

Working with batch message processing, Salesforce, file, and database connectors

Using MUnit and practising test-driven development

Experience with REST, HTTP, MQ, JSON, XML, and SOA

Familiarity with CI/CD pipelines

Education

Degree in a relevant field (e.g. Computer Science, Statistics)

Substantial experience in MuleSoft integration development (5+ years)

Tools

MuleSoft

CloudHub

MUnit

CI/CD tools (Maven, Jenkins, Bitbucket, Git)

Job description

Senior MuleSoft Developer

6 Month contract - Inside IR35 - up to 585 per day

London based - hybrid working - 3 days office based

Current NPPV3 clearance is highly desirable

Your main responsibility will be to deliver clean, maintainable, and well-tested code that adheres to SOLID principles. You will work collaboratively across Quality Assurance, DevOps, and other development teams, sharing knowledge, supporting onboarding, and contributing to code reviews.

Key Responsibilities

• Deliver high-quality, maintainable code and development outcomes.
• Manage data exchange between backend services, front-end applications, and third-party APIs.
• Develop server-side logic in collaboration with Business Analysts and QA, ensuring requirements are met and code is testable.
• Lead and contribute to technical user stories, focusing on integration and service optimisation.
• Document solutions using diagrams, flowcharts, and clear code comments.
• Ensure compliance with quality standards, including automated testing and code reviews.
• Address non-functional requirements such as performance, monitoring, and operational support.
• Support releases through all development environments, maintaining quality and reliability.
• Contribute to skill development and technology adoption within the team.
• Present technical concepts in demos and participate in user feedback sessions.
• Provide accurate work estimates and support agile planning.
• Balance delivery pace with documentation, test automation, and technical debt reduction.

Skills and Experience

We're looking for candidates with strengths in most of the following areas:

Essential

• Experience delivering integration microservices using MuleSoft best practices.
• Proven ability to write clean, maintainable code following SOLID principles.
• Designing RAML, REST APIs, flow control, and error handling.
• Hands‑on experience with the Anypoint Platform (CloudHub, VPC, VPN, DLB, firewalls, and cloud technologies).
• Securing and managing APIs using API Manager.
• Developing frameworks for error handling and logging.
• Managing the API development lifecycle from design to governance and management.
• Working with batch message processing, Salesforce, file, and database connectors.
• Using MUnit and practising test-driven development.
• Experience with REST, HTTP, MQ, JSON, XML, and SOA.
• Familiarity with CI/CD pipelines (Maven, Jenkins, Bitbucket, Git, MuleSoft).

Desirable

• Experience working in consulting or public sector environments.
• Experience as a microservices developer.
• MuleSoft certification.

Education and Other Requirements

• Typically, candidates have substantial experience in MuleSoft integration development (often 5+ years), but we welcome applicants with a range of backgrounds and relevant skills.
• Degree in a relevant field (e.g. Computer Science, Statistics) or equivalent practical experience.
• Eligible for SC clearance (requires 5 years' residency in the UK; citizenship is not mandatory).
• Able to adapt to changing priorities and client needs.

Disclaimer

This vacancy is being advertised by either Advanced Resource Managers Limited, Advanced Resource Managers IT Limited or Advanced Resource Managers Engineering Limited ("ARM"). ARM is a specialist talent acquisition and management consultancy. We provide technical contingency recruitment and a portfolio of more complex resource solutions. Our specialist recruitment divisions cover the entire technical arena, including some of the most economically and strategically important industries in the UK and the world today. We will never send your CV without your permission. Where the role is marked as Outside IR35 in the advertisement this is subject to receipt of a final Status Determination Statement from the end Client and may be subject to change.