26 to 48 of 48 API Design Jobs in London

Director, Forward Deployed Engineering

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
lead a team of elite engineers who embed directly with Fortune 500 customers to ship deeply integrated AI agents—owning everything from agent design and evaluation to the backend services, data systems, and cloud infrastructure that make them production‐ready. You'll partner closely with our Forward Deployed … volume for senior engineering roles. Hands‐on fluency with the full AI stack. Deep familiarity with LLMs and agent systems, evaluation frameworks, backend and API design (Python or TypeScript), data systems (PostgreSQL, DynamoDB, MongoDB, or similar), and cloud infrastructure (AWS, Azure, or GCP) including Kubernetes, Docker ...

Back-End Development Lead

Hiring Organisation
Oyster Consultant
Location
South East London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£80,000
evolve our stack and make constant improvements. Required Skills/Experience Strong C# development experience Experience with both .NET Core and .NET Web API Experience of building Microservices in .Net Core Experience using Message Based Architectures Experience using both SQL & NoSQL technologies Experience of API design Cloud ...

Software Engineer

Hiring Organisation
Corpay
Location
Central London, London, United Kingdom
Employment Type
Permanent, Work From Home
division. This position falls under our Cross Border line of business and is located in London. In this role, you will contribute to the design and development of our eMoney and FX payment systems. You will report directly to the Engineering Manager and collaborate closely with Product, Design … will set you up for success by providing: Assigned workspace or home office setup Company-issued equipment Role Responsibilities Provide significant contribution to the design, development, and maintenance of secure and scalable payment systems. Collaborate with engineering managers, designers, and product teams to gather and analyse requirements, implement technical ...

Pre-Sales Technical Architect for SaaS Integrations

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
client data will be sourced, validated, and integrated into Mondra, leveraging where possible our existing Import and Export APIs and identifying where custom API development may be required for fulfil Mondra’s data requirements. You will also contribute to the client contracting process, ensuring technical commitments are clearly defined … including mapping data sources, transformation logic, and validation processes. Identify the client’s BI requirements, and define data export strategies (preferably via existing Mondra API). Identify the authentication/authorisation capabilities of the client, and promote the integration with Mondra’s Identity Provider via Single Sign On. Leverage ...

Full Stack Engineer

Hiring Organisation
Total Recruitment Group
Location
West London, London, United Kingdom
Employment Type
Permanent
Salary
£85,000
role, with strong backend expertise in Typescript and Node and front capability in React Proficiency in SQL, Redux, cloud services (AWS or GCP), RESTful API design and GraphQL Strong analytical skills with the ability to design, optimise, and troubleshoot complex UIs Excellent communication and leadership skills; ability ...

Senior Full Stack Engineer (GCP, Python, JavaScript) Remote

Hiring Organisation
Exalto Consulting
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£400 - £410/day
assisted development workflows. ● Agile Experience: Proven track record working within Agile teams and participating in iterative delivery. ● Core Engineering: Proficiency in Git, REST API design, and modern CI/CD practices This is a great opportunity to work for an exciting organisation and to start ASAP. The role ...

Senior Python Engineer: AI Agents & Forecasting

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
LangChain or LangGraph (agent memory, tool calling, state management) Dagster in production (assets, sensors, partitions) or equivalent pipeline orchestration Strong backend fundamentals including API design, async programming, and database modelling You've built systems that had to work reliably at scale, not just pass a demo Experience 5+ ...

Lead Software Engineer

Hiring Organisation
MARSH CORPORATE SERVICES LIMITED
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
products (e.g., Concierge an agentic AI workflow tool, Prism a Mercer knowledge fabric for scheme data, and similar initiatives), from problem framing and design through build, release, and support. Translate risk advisory/consulting needs into clear technical requirements, user stories, and solution designs; partner with stakeholders through … Proven experience as a Tech Lead/Lead Engineer delivering production software, including hands-on coding and code review ownership. Strong backend engineering skills (API design, data modelling, performance) and experience building secure, role-based applications. Experience working directly with business stakeholders in a financial firm, with ...

Senior Developer

Hiring Organisation
Addition
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£70,000 - £90,000 per annum
improving APIs that support critical platform functionality Investigating production issues and tracing problems across distributed systems Working with product and engineering teams to design scalable solutions Improving reliability, observability and performance across existing services Reviewing code, sharing knowledge and helping raise engineering standards across the team Tackling real-world … APIs used by customers or internal teams Other Skills Needed: Solid backend engineering experience in C#, Java, or Go, with a strong grasp of API design and architecture. Hands-on experience managing and debugging production systems across cloud and self-managed infrastructure. Proven ability to navigate complex third ...

Ruby Developer

Hiring Organisation
Proactive Appointments
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP 70,000 - 80,000 Annual
develop new features, enhance existing systems, and ensure our platform remains stable and efficient. Your deep understanding of Rails architecture, PostgreSQL optimisation, and API design will be essential as you contribute to ongoing development projects. If you enjoy collaborating in Agile/Scrum environments, value clean code ...

Ruby on Rails Backend Engineer

Hiring Organisation
Rise Technical Recruitment
Location
Fulham, London, United Kingdom
Employment Type
Permanent
Salary
£60000 - £80000/annum Private Healthcare + Holiday + Pensi
evolution of core Ruby on Rails operational platforms. Optimise PostgreSQL performance and Sidekiq background job efficiency. Manage secure third-party integrations and RESTful API design. Partner with Platform teams on AWS and CI/CD reliability. The Person: Deep experience with Ruby on Rails and OOP. Expert in PostgreSQL ...

Backend Engineer (Python)

Hiring Organisation
17918
Location
London, United Kingdom
. A non-trivial piece of work you can walk us through and explain well. Good fundamentals: sound data modelling (SQLAlchemy/Alembic), sensible API design, and an instinct for testing. Care where it counts: you treat correctness as a feature, because this code generates real prescriptions … family. How we hire We keep it short and respect your time: Intro call with our engineers (25-30 mins), including a short system-design chat. A conversation with our Director of Software Engineering (30 mins). A practical take-home task, in your own time. Onsite ...

Principal Data Architect

Hiring Organisation
Experis
Location
City of London, London, United Kingdom
Employment Type
Contract
Contract Rate
£700 - £800 per day
Data platforms - Fabric, Snowflake, CosmoDB, DataBricks, MongoDB, RDBMS Data replication/CDC - Qlik Replicate, Oracle Golden Gate Data modeling - ERStudio Message-oriented data movement API design and access Data Analytics and AL/ML - AzureML Data virtualization Streaming data Data integration and ETL/ELT Tools - Matillion, Alteryx … NoSQL data stores, methods, and approaches (star and snowflake, dimensional modelling and third normal form) Experience with data security and data access controls and design Deep understanding of SoX, GDPR and Regulatory/CNI control environments In-depth experience in providing resolution to an extensive range of complicated data ...

Senior Software Engineer

Hiring Organisation
Platform Recruitment Limited
Location
City of London, London, United Kingdom
Employment Type
Permanent
heavily backend-biased position but given the size of the team you will be working across the stack when needed Build scalable, performant systems Design and deliver end-to-end features with direct impact on customer value Work with product and ML teams to help translate abstract and complex … software function About you: Strong ability across scalable and performant systems You have a product mindset Statically typed language expertise Experience with API design Low ego and love of engineering Full details are available. Please don't hesitate to get in touch for more information. ...

Software Engineer

Hiring Organisation
Platform Recruitment
Location
City of London, Greater London, United Kingdom
Employment Type
Permanent
Salary
£90000 - £160000/annum
heavily backend-biased position but given the size of the team you will be working across the stack when needed Build scalable, performant systems Design and deliver end-to-end features with direct impact on customer value Work with product and ML teams to help translate abstract and complex … software function About you: Strong ability across scalable and performant systems You have a product mindset Statically typed language expertise Experience with API design Low ego and love of engineering Full details are available. Please don't hesitate to reach out for more information. ...

Senior Software Engineer II (Java/ Spring)

Hiring Organisation
Elsevier
Location
Greater London, United Kingdom
Employment Type
Full Time
Salary
100400 to 167300 EUR Annually
Senior Software Engineer II , you will work with a passionate team that delivers scalable, reliable, and innovative solutions that accelerate scientific discovery. Key responsibilities: Design and implement graph-based search services. Develop applications using Java , Spring Boot, Spring, GraphQL , and GraphQL Federation . Integrate with databases, web services … Proven track record building scalable backend systems and APIs. Strong expertise in Java and the Spring Boot ecosystem . Hands-on experience with GraphQL API and REST API design. Solid background in cloud-native architectures with AWS and Kubernetes (EKS) . An advocate of best practices for rapid ...

IT Solutions Architect (Integration / Azure)

Hiring Organisation
DGH Recruitment
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
that supports business critical functions across the business. My client have migrated significant services to the cloud and now requires a lead architect to design and build the next generation of solutions including core finance and HR technology landscape, automating data flows, integrating systems, supporting in the delivery … real-time reporting and analysis, whilst driving a more mature awareness to data architecture and governance across the business. Responsibilities: - Lead the design and delivery of integrations across technology platforms and solutions. - Produce architectural documentation (HLDs, LLDs, diagrams, support guides). - Ownership of integration and application architecture in alignment ...

Backend Engineer

Hiring Organisation
Robert Half
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
Salary negotiable
Live platform Contributing to a shared transaction layer used across multiple products Collaborating with frontend and mobile engineers to deliver consistent experiences Key Responsibilities Design and build backend services end-to-end Contribute to platform and API design decisions Improve system performance and reliability Work within … evolving architecture with real production constraints Profile The Backend Engineer will have strong API and service development skills Experience working on transaction systems, payments, or eCommerce platforms is required Experience with GraphQL preferred Exposure to Elixir, Go, or similar backend technologies Ability to work effectively in ambiguous, fast-changing ...

Java Software Engineer

Hiring Organisation
Michael Page
Location
City of London, London, United Kingdom
Employment Type
Permanent
Salary
£50000 - £60000/annum
efficiency and excellence in every project. Description Develop and maintain Java-based software applications to meet client requirements. Collaborate with cross-functional teams to design and implement efficient technical solutions. Perform code reviews to ensure high-quality standards and best practices. Analyse and resolve technical issues and software bugs … familiarity with ORM frameworks (Hibernate/JPA). * Practical experience with trunk-based development. * Working knowledge of OAuth2/OpenID Connect, JWT, and secure API design. * Experience with CI/CD pipelines (Azure DevOps). * Demonstrated hands-on exposure to at least one of: LLM API integration, vector ...

Java Software Engineer

Hiring Organisation
Michael Page Technology
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£50,000 - £60,000 per annum
efficiency and excellence in every project. Description Develop and maintain Java-based software applications to meet client requirements. Collaborate with cross-functional teams to design and implement efficient technical solutions. Perform code reviews to ensure high-quality standards and best practices. Analyse and resolve technical issues and software bugs … familiarity with ORM frameworks (Hibernate/JPA). * Practical experience with trunk-based development. * Working knowledge of OAuth2/OpenID Connect, JWT, and secure API design. * Experience with CI/CD pipelines (Azure DevOps). * Demonstrated hands-on exposure to at least one of: LLM API integration, vector ...

Senior Software Engineer I – Search and AI Platform

Hiring Organisation
Elsevier
Location
Greater London, United Kingdom
Employment Type
Full Time
Salary
86900 to 144600 EUR Annually
Senior Software Engineer II , you will work with a passionate team that delivers scalable, reliable, and innovative solutions that accelerate scientific discovery. Key responsibilities: Design and implement graph-based search services. Develop applications using Java , Spring Boot, Spring, GraphQL , and GraphQL Federation . Integrate with databases, web services … Proven track record building scalable backend systems and APIs. Strong expertise in Java and the Spring Boot ecosystem . Hands-on experience with GraphQL API/REST APIs design. Solid background in cloud-native architectures with AWS and Kubernetes (EKS) . An advocate of best practices for rapid development ...

AWS Technical Architect

Hiring Organisation
Opus Recruitment Solutions
Location
Remote work, South Bank, Greater London, United Kingdom
Employment Type
Contract
Contract Rate
£0 - £600/day
/Public Sector client on a long-term contract. Key Details: You'll be working within a large-scale public sector environment, helping to design and shape modern, scalable architectures that support critical government services. Experience Cloud & architecture expertise - strong AWS architecture experience, including event-driven systems (e.g. Kafka … RESTful API design. Data & public sector experience - experience with document-based databases (e.g. MongoDB) and a solid understanding of public sector governance and assurance processes. Strong technical architecture background - experience designing secure, scalable systems using modern technologies (cloud, open source, and languages like Java, Python, JavaScript or Ruby). ...

Full Stack Engineer

Hiring Organisation
TOTTENHAM HOTSPUR FOOTBALL & ATHLETIC CO LTD
Location
Enfield, London, United Kingdom
Employment Type
Permanent
where your decisions matter. The data you work with is as rich and complex as it gets in professional sport. Key Responsibilities Application Development Design, build and maintain internal web applications across the full stack, from database to UI. Own the frontend experience on the products you work … code quality in your team. Data and Infrastructure Work directly with data engineers to understand data models, query patterns and pipeline outputs. Design and build efficient API layers that expose complex data in a way that is fast, reliable and easy to consume. Take ownership of cloud infrastructure ...