26 to 40 of 40 API Design Jobs in London

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 ...

Lead Python Developer

Hiring Organisation
Total Recruitment Group
Location
South East London, London, United Kingdom
Employment Type
Permanent
Salary
£85,000
stuck into some genuinely interesting engineering. Think computational complexity, mathematical optimisation, and performance challenges at scale - a long way from your average API job. Requirements: 7+ years experience developing and maintain scalable Python/FastAPI back-end services Ideally worked with high-performance APIs for complex hierarchical data queries … code Lead technical planning by breaking down roadmap items into scoped engineering work, driving ADRs and setting standards for code quality, testing, and API design Collaborate cross-functionally with front-end, data engineering, modelling and product teams to deliver reliable, impactful features Line-manage a team ...

Principal iOS Engineer - Search and Recommendations Experience

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
Overview Expedia Group brands power global travel for everyone, everywhere. We design cutting-edge tech to make travel smoother and more memorable, and we create groundbreaking solutions for our partners. Our diverse, vibrant, and welcoming community is essential in driving our success. Introduction to Team: Our Technology Team partners … discovery experiences, setting architectural direction, influencing engineering standards, and shaping the evolution of AI-enabled capabilities across the mobile platform. Responsibilities Lead the design, development, and maintenance of advanced iOS applications, ensuring high performance, quality, and responsiveness across Expedia Group’s product suite. Architect and implement robust, scalable system ...

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. ...

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, UK
Employment Type
Full-time
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 ...

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 ...

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). ...