26 to 50 of 50 API Design Jobs in London

Technical Architect

Hiring Organisation
Sphere Digital Recruitment
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£80,000 - £90,000 per annum
office Technical Architect About the role This is a rare opportunity to join a government-backed initiative at a very early stage, helping to design and deliver a new digital platform that enables transparent licensing and ethical access to high-quality digital content at scale. We are assembling … that the platform is secure, intuitive, and reliable for all users. This is a hands-on architecture role focused on system design and technical delivery rather than business development or account management. The role also plays a key part in shaping the future technical service offering by applying lessons ...

Senior Backend Engineer (TypeScript/Ruby)

Hiring Organisation
Oliver Bernard
Location
London Area, United Kingdom
experiences at scale. Package 💷 £70–90k + 5% bonus 🏢 Hybrid (2 days onsite, London) What you’ll do Own the full lifecycle of services: API design, architecture, deployment, and production Build an internal platform delivering consistent, real-time communications across multiple digital touchpoints Collaborate with Product, Data, Marketing ...

Senior Scala Developer

Hiring Organisation
SF Recruitment
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£60,000 - £90,000 per annum
following key skills: - At least 4 years commercial Scala programming - Strong framework experience (Akka, Play etc) - Relational database experience - PostgreSQL - MongoDB, NoSQL - RESTful API design and integration experience - Solid unit test understanding - Spec2, scalaTest etc - Experience working in a TDD/BDD driven environment - Containerization experience - Docker, Kubernetes … well-established friendly team then please apply now to be considered and for further details. Senior Scala Developer Up to £90,000 Scala, REST Api, NoSQL, TDD/BDD, functional programming, CI/CD, Play, Akka ...

Site Reliability Engineer

Hiring Organisation
McGregor Boyall
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£90,000 - £95,000 per annum
SLOs, and participating in support rotas. Coding/scripting experience (Python/Bash) in a commercial setting. Database knowledge, streaming and batch operations, and API design. Good background with Kubernetes (ideally microservice architectures using Istio service mesh). Extensive experience with cloud-native solutions (ideally Google Cloud). Solid ...

Founding Engineer (Full Stack / Backend)

Hiring Organisation
Affinity Labs
Location
City of London, London, United Kingdom
early-stage, hands-on role with significant autonomy and responsibility to drive backend product development, collaborating closely with founders, creators, and product/design to turn lean specs into reliable, scalable services. Responsibilities Implement features end-to-end on the backend (APIs → data models → integrations) and maintain quality while … z2bz0 years building production backends/services , with shipped work and clear ownership. Strong Python (FastAPI) and database skills ( PostgreSQL/MongoDB ); solid API design fundamentals. Familiarity with AWS serverless patterns and Docker for bespoke services; basic CI/CD concepts. Comfortable with Redis (caching/sessions ...

Senior Software Engineer

Hiring Organisation
Stott and May
Location
City of London, London, United Kingdom
onsite) Salary: Up to £80k DOE Type: Perm Job Description We are looking for a passionate Senior Java Engineer in London to lead the design and development of core product features and services that power an app used by thousands of travellers on a daily basis. As a Senior … impactful product features Ensure the quality of the features you built, follow-up on usage/issues post release. Work closely with product and design team to deliver new features that align with the needs of the business Provide technical leadership and mentoring to other engineers on the team ...

Back End Developer

Hiring Organisation
Stott and May
Location
London Area, United Kingdom
onsite) Salary: Up to £80k DOE Type: Perm Job Description We are looking for a passionate Senior Java Engineer in London to lead the design and development of core product features and services that power an app used by thousands of travellers on a daily basis. As a Senior … impactful product features Ensure the quality of the features you built, follow-up on usage/issues post release. Work closely with product and design team to deliver new features that align with the needs of the business Provide technical leadership and mentoring to other engineers on the team ...

Senior Software Engineer

Hiring Organisation
ZEREN
Location
London, UK
Employment Type
Full-time
founding team Build technology that fundamentally changes how teams use data What We Are Looking For Strong experience building in Python Deep understanding of design patterns and system architecture Experience building scalable, performant platforms Strong grasp of event-driven systems and concurrency Solid database and API design … Have Zero-to-one product experience, including OSS or side projects Data engineering experience such as pipelines and analytics Experience integrating LLMs, including prompt design and understanding model capabilities Deeper cloud experience, especially with GCP Experience with Encore, though this is easy to pick up Ways of Working Ownership ...

Salesforce &/ React Native Developer

Hiring Organisation
Atrium Workforce Solutions Ltd
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£500 - £550 per day
IR35) Sector: Banking Key Skills & Experience Salesforce +5 years experience AND/OR React Native (Web) +5 years Java +5 years TDD, BDD RESTful API design & build OAS/YAML Unit Testing GitLab CI/CD Pipelines Agile practitioner, SonarQube, Veracode, Jira, Confluence Banking/Financial services background ...

C# Developer

Hiring Organisation
VIQU IT
Location
City, London, United Kingdom
Employment Type
Contract
Contract Rate
GBP 300 - 350 Daily
Developer: Must have a strong background in C#/.NET development. Experience of PostgresSQL or other SQL databases. CI/CD experience. Experience in API design and building system integrations. Microsoft Dynamics integration (highly desirable). Python and/or JavaScript experience (desirable). Excellent communication skills ...

C# Developer

Hiring Organisation
VIQU IT
Location
London, Coleman Street, United Kingdom
Employment Type
Contract
Contract Rate
£300 - £350/day
Developer: Must have a strong background in C#/.NET development. Experience of PostgresSQL or other SQL databases. CI/CD experience. Experience in API design and building system integrations. Microsoft Dynamics integration (highly desirable). Python and/or JavaScript experience (desirable). Excellent communication skills ...

Software Engineer

Hiring Organisation
Bounce Digital
Location
City of London, London, United Kingdom
Great Fit If You: Have 5+ years’ experience building production-grade web apps with React + TypeScript Are comfortable across the stack - API design through to front-end polish Have experience with AWS or similar cloud infrastructure Care about ownership, quality, and impact Are curious about AI, automation ...

Monitoring Tools Support, Assoc Manager / Specialist

Hiring Organisation
Accenture
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
Competitive salary
Tooling Expertise: Use Prometheus, Grafana, and Dynatrace for data collection, visualisation, and deep-dive analysis. •Proficiency in Prometheus, Grafana, and Dynatrace. •Strong knowledge of API design, data modelling, and pipelines. •Experience with automation, monitoring platforms, and scripting languages (e.g., Python, PowerShell, Bash, Terraform and Ansible) to enhance operational ...

AI Engineer

Hiring Organisation
Tenth Revolution Group
Location
City of London, London, United Kingdom
Employment Type
Contract
Contract Rate
£250 - £300/day
similarity matching - Context window management and chunking strategies MCP & Tool Integration: - Model Context Protocol (MCP) implementation - Tool calling and function integration with LLMs - API design for LLM tool interfaces - AWS Lambda integration with agents AI Safety & Evaluation: - Guardrail implementation (hallucination detection, toxicity filtering) - Response evaluation framework design ...

AI Engineer

Hiring Organisation
Tenth Revolution Group
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£250 - £300 per day
similarity matching- Context window management and chunking strategies MCP & Tool Integration:- Model Context Protocol (MCP) implementation- Tool calling and function integration with LLMs- API design for LLM tool interfaces- AWS Lambda integration with agents AI Safety & Evaluation:- Guardrail implementation (hallucination detection, toxicity filtering)- Response evaluation framework design ...

Security Engineer

Hiring Organisation
Red - Specialist Recruitment
Location
EC3V, Langbourn, Greater London, United Kingdom
Employment Type
Permanent
security expertise to projects built on multiple platforms, such as Salesforce and Azure Exposure to Cloud Native software development, including cloud infrastructure and API design (Azure preferred) Proven experience applying modern standards such as OWASP CI/CD, DSOMM, SAMM etc Strong networking protocol knowledge (TCP/… HTTP/3, AMQP, streaming protocols etc), cloud network design (VPNs, subnets, regions/zones etc), and integration related technologies (Auth0, APIM) Expertise with SAST & SCA systems such as Snyk, Checkmarx Experience with DAST systems such as OpenZAP, Qualys DAST (preferred) ideally with HTTP APIs Ability to manage large ...

Senior Test Engineering Manager Automation-First

Hiring Organisation
Salt Search
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£480 - £500 per day
automated testing into CI/CD pipelines so quality is continuous and enforced Upskill and mentor test engineers and software engineers in automation, test design, and quality engineering Establish quality standards, best practices, and governance without slowing teams down Reduce manual testing, flaky automation, and release risk Partner with … engineering leadership to raise overall engineering maturity Influence system and API design to improve testability, resilience, and maintainability Essential experience A software engineer at heart with senior test engineering leadership experience Proven track record of creating and evolving test strategies, not just executing them Experience building and scaling ...

Senior Android Engineer - Hybrid, £100K

Hiring Organisation
Oliver Bernard
Location
London Area, United Kingdom
share code with iOS. You’ll be joining a collaborative engineering group working on major new features, shaping technical discussions, influencing architecture and API design, and helping to evolve a category-defining product used across the UK, US and several new international markets launching in 2026. What they ...

Junior Full Stack Developer

Hiring Organisation
Proactive Appointments
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£30,000 - £38,000 per annum
/Junior Full Stack Developer to join their team on a permanent basis. This role focuses on building and optimising JavaScript applications with strong API design and architecture. If you’re passionate about technology and continuous learning, the organisation can offer excellent career growth, competitive compensation, and great ...

Senior React & Java Engineer - London

Hiring Organisation
Opus Recruitment Solutions Ltd
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£1 - £85,000 per annum
elevate team capability What we expect from you? Strong experience with React, TypeScript/JavaScript and another BE language such as Java Understanding of API design, integration and security Experience with relational databases A track record of delivering complex systems with clean architecture Interested in learning more ...

Security Engineer

Hiring Organisation
Tenth Revolution Group
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£70,000 - £85,000 per annum, Inc benefits
monitoring solutions to improve visibility, reliability and overall platform performance Skills & Experience Required: Experience with cloud-native software development, including cloud infrastructure and API design (Azure preferred) Willingness to apply security and engineering expertise across multiple platforms, such as Azure and SaaS solutions Proven experience working with modern ...

Machine Learning Engineer

Hiring Organisation
RevTech
Location
London, UK
Employment Type
Full-time
reliable, auditable workflows. You'll take full ownership of projects, shape the technical direction from the ground up, and grow your career. Stack: Python, API design, Neo4j, Graph schemas, ML/LLM integration/deployment What do you need? Strong backend engineering experience with Python Experience building production ...

Backend Engineer

Hiring Organisation
Harnham - Data & Analytics Recruitment
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£60,000 - £80,000 per annum
TypeScript will be valuable for occasional UI enhancements and bridging front-end requirements. Collaboration with cross-functional teams to implement best practices in API design, security, and performance tuning will be central to success. Additionally, you'll contribute to code reviews, documentation, and continuous improvement initiatives to maintain ...

Staff Kotlin Engineer

Hiring Organisation
George Blake
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP 80,000 - 90,000 Annual
looking for a Staff Kotlin Engineer to provide technical leadership and drive the development of our next-generation platforms. Key Responsibilities Lead the design and implementation of scalable, high-performance software solutions using Java and Kotlin. Provide technical direction and mentorship to a team of engineers. Drive architectural decisions … Master s degree in Computer Science, Engineering, or a related field. Extensive experience in backend development using Java and Kotlin. Deep understanding of software design patterns, data structures, and algorithms. Proven experience in system architecture and designing distributed systems. Familiarity with cloud platforms (e.g., AWS, GCP, Azure) and containerization ...

Staff Kotlin Engineer

Hiring Organisation
George Blake
Location
W1, Marylebone High Street, Greater London, United Kingdom
Employment Type
Permanent
Salary
£80000 - £90000/annum
looking for a Staff Kotlin Engineer to provide technical leadership and drive the development of our next-generation platforms. Key Responsibilities Lead the design and implementation of scalable, high-performance software solutions using Java and Kotlin. Provide technical direction and mentorship to a team of engineers. Drive architectural decisions … Master’s degree in Computer Science, Engineering, or a related field. Extensive experience in backend development using Java and Kotlin. Deep understanding of software design patterns, data structures, and algorithms. Proven experience in system architecture and designing distributed systems. Familiarity with cloud platforms (e.g., AWS, GCP, Azure) and containerization ...