26 to 50 of 53 API Design Jobs in London

Contract Senior Software Engineer (Java or Python)

Hiring Organisation
SoCode Limited
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP 650 - 700 Daily
generated code for correctness, security, and financial accuracy Desirable, but no essential: Experience with Apache Airflow or similar workflow schedulers REST or GraphQL API design experience Knowledge of fixed income, FX, or derivatives products and associated P&L/risk methodologies ...

Contract Senior Software Engineer (Java or Python)

Hiring Organisation
SoCode Limited
Location
London, Baker Street, United Kingdom
Employment Type
Contract
Contract Rate
£650 - £700/day
generated code for correctness, security, and financial accuracy Desirable, but no essential: Experience with Apache Airflow or similar workflow schedulers REST or GraphQL API design experience Knowledge of fixed income, FX, or derivatives products and associated P&L/risk methodologies ...

Full Stack Software Engineer

Hiring Organisation
83zero Limited
Location
City of London, London, United Kingdom
Employment Type
Permanent
roles, with a track record of building solutions end-to-end Experience deploying applications in cloud environments, preferably Microsoft Azure Strong experience in REST API design and OpenAPI standards Extensive experience working with databases, data platforms, and analytical tools Ability to research, propose, and implement solutions with minimal ...

Full Stack Software Engineer

Hiring Organisation
83zero Ltd
Location
London, Lime Street, United Kingdom
Employment Type
Permanent
Salary
£100000 - £130000/annum
roles, with a track record of building solutions end-to-end Experience deploying applications in cloud environments, preferably Microsoft Azure Strong experience in REST API design and OpenAPI standards Extensive experience working with databases, data platforms, and analytical tools Ability to research, propose, and implement solutions with minimal ...

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+ ...

Senior iOS Engineer – SEO Product

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
growth, starting with the Wise Currency Converter app developing it into a best‐in‐class travel money companion. You’ll work closely with product, design, analytics, marketing and engineering from the earliest stages of an idea. We want someone who is comfortable shaping what we build, making technical decisions … other engineers to shape ideas, define requirements, and turn them into simple, high‐quality customer experiences Owning iOS development end‐to‐end, from technical design through implementation, release, and iteration Own the observability and reliability of the app, including incident management and working hours support Making architecture decisions ...

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 ...

Principal Solutions Architect

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
working hours, patterns and locations to suit you and our business. About the Opportunity As a Principal Solutions Architect, you will specialise in the design, development and governance of integrated digital project controls environments across major capital programmes. This is not a general IT solutions architecture role. … needed. Key Responsibilities Define enterprise aligned solution architectures for programme controls platforms covering cost, schedule, risk, performance reporting and data governance. Lead evaluation, selection, design and configuration of programme controls systems such as EcoSys, Oracle Primavera P6 and Unifier, Aconex, CDEs including SharePoint and ProjectWise, and related digital delivery ...

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 ...

Manager, Engineering - Managed Services (Hybrid)

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
delivering multiple major milestones of products.* Experience building scalable distributed systems running in public and/or private cloud environments.* Knowledgeable of REST, API design patterns and microservices.* Experience managing Full stack development teams, engineers working on UI Development and backend services.* Familiarity with Container orchestration technologies ...

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 ...

Product Manager

Hiring Organisation
Randstad Technologies Recruitment
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£80000 - £110000/annum
Technical Skills Required Data Tools: SQL, Python, Snowflake/Databricks, Tableau/Power BI. Frameworks: Agile/Scrum, MLOps, Data Governance, Metadata Management. Integration: API design, event-driven architecture, and data modeling. Randstad Technologies is acting as an Employment Business in relation to this vacancy. ...

Senior Product Engineer - End-to-End, AI-Driven Platform

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
with LLM integration, and working across the stack with React/TypeScript. The ideal candidate will have strong experience in Python, product delivery, and API design. The role offers a competitive salary package, significant equity, full private healthcare, and wellness benefits. #J-18808-Ljbffr ...

Staff Software Engineer

Hiring Organisation
Hays Specialist Recruitment Limited
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£120,000 - £135,000 per annum
engineers across the organisation What you'll need to succeed 8+ years' experience in software engineering, with strong fundamentals in distributed systems and system design Proven background building and operating large-scale backend platforms in production Experience working within a product-led environment Hands-on experience with cloud-native … technologies, containers, and CI/CD pipelines Experience influencing technical direction across teams or domains Strong expertise in: Java Distributed systems architecture API design Performance optimisation and scalability Nice to have: Previous experience at Staff/Principal/Tech Lead level Exposure to high-volume, low-latency data ...

Software Developer

Hiring Organisation
Randstad Technologies Recruitment
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£550 - £585/day
complex risk calculations and high-throughput financial data processing. This is an environment where your technical expertise in Object-Oriented Programming (OOP) and API design will directly impact global operations and regulatory compliance. Key Responsibilities Engineering: Build scalable, testable, and maintainable applications using .NET Core and RESTful APIs … systems. Collaboration: Work alongside Quants, Risk Managers, and Front Office teams to translate business needs into technical reality. Architecture: Participate in high-level technical design and architectural discussions to evolve the platform. Requirements Technical Core: Extensive experience in C#, .NET, SQL Server, and CI/CD pipelines. Domain Expertise ...

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 ...

Backend Engineer

Hiring Organisation
Randstad Technologies Recruitment
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£500 - £522/day
Expert Developer: Java experience (Spring Boot, Bazel, Maven) with a focus on distributed services and Kubernetes (GKE). System Designer: Strong skills in API design (gRPC, GraphQL, REST) and relational databases like PostgreSQL. Cloud Proficient: Hands-on experience with GCP services, including BigQuery and Cloud SQL. Security Minded ...

Senior Consultant - Hybrid (Product / Transformation / Architecture), TC, FS

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
Requisition ID: 1686605 Role highlights Early‐career hybrid who connects product, delivery and architecture. Shape stories, scenarios and NFRs with traceability to design/build. Support domain modelling and interface specifications for core programmes. Your key responsibilities Backlog shaping: user stories, scenarios, acceptance criteria and NFRs; maintain definition … ready/done. Architecture support: contribute to domain models, interface specs and API/event definitions; maintain requirements‐to‐build traceability. Delivery hygiene: reporting, risks/decisions, demos and release readiness; contribute to playbooks and templates. Continuous learning across domain, product and technical skills (DDD, data flows, integration basics ...

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 ...

IT Integration Architect

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 ...

Software Architect

Hiring Organisation
Ventula Consulting
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP 120,000 Annual
fast-growing and dynamic team. This is an exciting opportunity to work on cutting-edge projects, collaborating with engineers, stakeholders, and business leaders to design and deliver high-impact software systems. Tech Stack: Frontend: Angular.JS/TypeScript Backend: Swift (Swift Vapor) Key Responsibilities Lead the architecture and design … roles. Strong expertise with Angular.JS/TypeScript. Solid hands-on experience with Swift, ideally Swift Vapor for Back End services. Proven track record in API design and development. Excellent interpersonal and communication skills to engage with both technical and non-technical stakeholders. Package & Location Salary ...

Product Technical Lead

Hiring Organisation
83zero Limited
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£700 - £701 per day
Senior Technical Product Lead - API & Data Platforms London - Hybrid (2/3 days onsite) 6 Month Contract £700 (Outside IR35) 83zero are partnered with a leading London-based organisation currently undergoing a major digital and platform transformation programme. We are looking for an experienced Technical Product Lead to help … shape and drive the evolution of enterprise API and Data Platform capabilities within a complex, fast-moving environment. This is not a traditional Product Owner role focused purely on delivery management. This position sits at the intersection of product strategy, platform engineering, architecture, and stakeholder engagement. The successful candidate ...

Principal iOS Engineer - Search and Recommendations Experience

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
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 … API designs, including effective data modeling to support complex business requirements. Drive cross‐functional collaboration to define, develop, and ship impactful features, ensuring alignment with organizational goals and technical strategy. Champion best practices in software engineering, testability, and maintainability through code reviews and mentoring. Safely integrate and operate ...

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. ...

Principal Android Architect — AI-Driven Travel Search

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
experiences. The ideal candidate should have over 12 years of experience in Android application development and must possess a strong command of Kotlin and API design. This position offers an opportunity to work within a vibrant team focused on innovative solutions in the travel industry. #J-18808-Ljbffr ...