26 to 50 of 63 API Design Jobs in London

Front End React Developer

Hiring Organisation
Ascend Consulting
Location
North West London, London, England, United Kingdom
Employment Type
Full-Time
Salary
£40,000 - £80,000 per annum
will coordinate with the rest of the team working on different layers of the infrastructure. Therefore, a commitment to collaborative problem solving, sophisticated design, and quality product is important. Responsibilities Working in a team of Front-End engineers Writing clear & concise code Working closely with Back-End engineers Participate … architecture design code reviews API design with the Back-End engineers and other team members to establish more functional, cohesive code Create, maintain documentation while implementing the best coding practices standards Hands-on approach Participation in sprint rituals What you’ll need 6+ years experience developing large ...

Data Engineer

Hiring Organisation
Above & Beyond - Climate Tech Recruitment
Location
City of London, London, United Kingdom
that integrate development finance datasets (e.g. OECD, IATI, World Bank, IMF, WHO, etc.) into a unified knowledge graph. Scaling the Knowledge Graph, including schema design, data integration, and optimisations. Developing the data quality framework, implementing provenance tracking, quality indicators, coverage metrics, and automated testing so that every data point … Spanner through the Data Commons infrastructure, alongside BigQuery for internal analytical workloads and MySQL for supporting services. Key responsibilities: Data infrastructure and pipelines Design, build, and maintain open-source ETL/ELT pipelines that ingest, clean, transform, and deliver development finance data from multiple sources. Contribute to data modelling ...

Senior Technical Architect

Hiring Organisation
Cognizant
Location
London, United Kingdom
Employment Type
Permanent
alignment between technical and business leaders, balancing strategic direction with delivery needs. Represent architecture in governance forums, supporting prioritization, risk discussions, and assurance reviews. Design, Analysis & Governance Create high-quality architectural artefacts including diagrams, data flows, integrations, future-state designs, and migration pathways. Evaluate technology options and assess impacts … digital or enterprise environments. Strong software engineering foundation, with practical knowledge of modern application architectures (e.g., microservices, APIs, distributed systems). Proven ability to design and document architectures using visual modelling techniques such as C4, UML, and data flow diagrams. Hands-on experience with at least one major cloud ...

Senior Full Stack Developer (Node.js, AWS, React)

Hiring Organisation
Radioplayer
Location
London Area, United Kingdom
APIs, managing infrastructure with Cloudformation, and building modern user interfaces with React. You will work on a high-traffic system that handles billions of API calls, requiring strong attention to scalability, performance, and reliability. Key Responsibilities Design, develop, and maintain microservices and RESTful APIs (Node.js + AWS Lambda … Handle data and queries using relational databases (e.g., PostgreSQL) Collaborate in designing and developing the user interface using React Integrate and monitor AWS services (API Gateway, S3, CloudWatch, RDS, CloudFront, etc.) Ensure testability, code quality, and DevOps best practices Technical Requirements Minimum of 5 years of experience in full ...

Senior Software Engineer

Hiring Organisation
Retelligence
Location
City of London, London, United Kingdom
core stack includes: The Engine: Expert-level C# and .NET Core mastery. Architecture: Deep understanding of SOA (Service Oriented Architecture) and complex Object-Oriented design patterns. System Dynamics: Specialized knowledge of concurrency, asynchrony, and parallelism —essential for real-time transactional processing. Data & Web: High proficiency in SQL Server … API design, and modern front-end fundamentals (HTML/CSS/JS). Reliability: A strict practitioner of TDD (Test Driven Development) and robust CI/CD processes. Desired Innovations Our client is actively modernizing. Exposure to the following is highly valued: Cloud & Orchestration: Azure ecosystems, Docker ...

Confluent Engineer

Hiring Organisation
LA International Computer Consultants Ltd
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP 403 Daily
function, responsible for enabling Real Time data, event-driven architecture, and high-performance integrations across the organisation. * The ideal candidate will contribute to the design, development, and scaling of Intact's Confluent-based streaming platform, supporting teams across the organisation in adopting event-driven approaches. * This opportunity sits within … modernisation programme, leveraging Agile and DevOps practices to continuously deliver business value. Key Accountabilities * Deliver engineering tasks across the Confluent Streaming Platform, including the design, development, testing, and deployment of event-driven services and data pipelines. * Develop Kafka topics, schemas, and streaming applications using Kafka, Kafka Connect, Schema Registry ...

Confluent Engineer

Hiring Organisation
eTeam Workforce Limited
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP Daily
function, responsible for enabling Real Time data, event-driven architecture, and high-performance integrations across the organisation. The ideal candidate will contribute to the design, development, and scaling of Intact's Confluent-based streaming platform, supporting teams across the organisation in adopting event-driven approaches. This opportunity sits within … modernisation programme, leveraging Agile and DevOps practices to continuously deliver business value. Key Accountabilities Deliver engineering tasks across the Confluent Streaming Platform, including the design, development, testing, and deployment of event-driven services and data pipelines. Develop Kafka topics, schemas, and streaming applications using Kafka, Kafka Connect, Schema Registry ...

Technical Lead - TypeScript / Node.js

Hiring Organisation
Adria Solutions Ltd
Location
London, United Kingdom
Employment Type
Permanent
Salary
£60000 - £80000/annum
fast-moving startup environment. The Role Technical Strategy & Leadership Work alongside the founder to define and evolve the technical roadmap Lead architectural design and critical technology decisions Champion engineering best practices, code quality, and technical excellence Mentor, coach, and grow engineers at all levels Foster a culture of ownership … collaboration, and innovation Backend Architecture & Development Architect, build, and scale backend services and RESTful APIs Design, optimise, and maintain MongoDB database solutions Improve system reliability, performance, and scalability Resolve complex production issues with robust solutions Implement microservices and modern backend patterns Collaboration & Delivery Partner with Product, Design ...

Senior Platform Engineer

Hiring Organisation
collects.io
Location
City of London, London, United Kingdom
pure DevOps role. You will spend significant time on platform engineering, CI/CD, and infrastructure – but you will also contribute to application development, API design, and integration work. We need a generalist who leans platform, not an infrastructure specialist who only touches pipelines. What … fast diagnosis and recovery. • Define and track availability and reliability targets; drive post-incident review and preventative improvements. Application Development • Contribute to backend development: API endpoints, service logic, database schema, and integration code. This is a building role, not only an operations role. • Design and implement integration patterns ...

Full Stack Engineer (Typescript) - Health Tech AI

Hiring Organisation
AMP People
Location
City of London, London, United Kingdom
momentum Technical skills required: Strong TypeScript across both frontend and backend (Node.js) Modern frontend framework experience (React or similar) RESTful and/or GraphQL API design and development Database design and querying (SQL and/or NoSQL) Experience in regulated or data-sensitive industries a strong advantage ...

Software Engineering Team Lead .NET / C#

Hiring Organisation
McGregor Boyall
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£110,000 - £125,000 per annum
remaining close to complex technical problem-solving. Key Responsibilities Lead and develop a high-performing engineering team Own delivery outcomes, quality, and engineering standards Design and evolve distributed, event-driven systems Partner with architecture and senior engineering stakeholders Drive continuous improvement across tooling, CI/CD, and testing Communicate … experience leading engineering teams in an Agile environment Strong expertise in C# and modern .NET/.NET Core Experience building distributed, event-driven systems API design and development (REST, GraphQL) Relational databases (SQL Server, MySQL, or similar) Cloud platforms such as AWS or Azure Solid understanding ...

Full Stack Engineer

Hiring Organisation
Searchability®
Location
London Area, United Kingdom
Python and Django and strong skills in TypeScript and React. Minimum 5 years of experience writing excellent, standards-compliant code. Demonstrated ability to independently design, build, and maintain production-grade software systems. Experience working on the engineering team in a start-up, scale-up or product-driven company Experience … reliably under increasing load. Strong experience writing high-quality, maintainable, standards-compliant code in production systems. Strong understanding and experience with building and consuming API-driven solutions. Demonstrable experience with Agile or Scrum software development methodologies. Specific Technology Focus Experience with database technologies, cloud platforms (e.g., AWS, Azure ...

Senior Full Stack Engineer (Team Lead)

Hiring Organisation
Futuria
Location
City of London, London, United Kingdom
development tools across your team Foster culture of learning, experimentation, and knowledge sharing Work with Head of Engineering on architecture, partner with product and design teams About You You're a strong senior engineer ready to lead a team but who still loves writing code. You have solid technical … Strong expertise in Python backend development with async patterns Production experience with modern frontend frameworks (React, TypeScript) Solid understanding of distributed systems architecture and API design Experience with container orchestration, CI/CD, and cloud platforms Experience with NoSQL databases and data modelling Daily user of AI-assisted ...

Junior Back-end Engineer

Hiring Organisation
ivee
Location
City of London, London, United Kingdom
maintain server-side logic using modern backend frameworks (e.g. Node.js, Python, Go) Work with APIs — designing, integrating, and maintaining RESTful endpoints Support database design and optimisation (e.g. PostgreSQL, MongoDB) Collaborate with front-end and product teams to deliver full-stack features Write clean, testable, and maintainable code Help improve ...

Full Stack Engineer

Hiring Organisation
Humanoid
Location
City of London, London, United Kingdom
create the world’s leading, commercially scalable, safe, and advanced humanoid robots that seamlessly integrate into daily life and amplify human capacity. Responsibilities Design and implement a centralized cloud-based platform for managing a fleet of humanoid robots, monitoring system health, and visualizing fleet-level KPIs Develop robust backend … Expertise Proficiency in one of Python, Javascript, Golang or Rust Familiarity with React (or similar frameworks) for creating user-friendly web applications. Expertise in API design, data modeling, and distributed architectures Proficiency with CI/CD pipelines, containerization (e.g., Docker, Kubernetes), and workflow automation. Proficiency in infrastructure ...

Senior Manager - Delivery Lead - Tier 1 Global Consultancy

Hiring Organisation
Robert Walters
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£90,000 - £110,000 per annum
highly valued. Your approach should emphasise breaking down complex challenges into actionable steps while maintaining focus on scalability and resilience. Familiarity with modern API design principles is essential alongside practical skills in database management-both relational systems and emerging NoSQL solutions. You should bring hands-on involvement with ...

Mid-Senior Ruby on Rails Engineer (B2B SaaS | Hybrid | UK)

Hiring Organisation
Transreport
Location
City of London, London, United Kingdom
architecture Extensive experience with PostgreSQL, including performance tuning and complex queries. Experience with background job processing using Sidekiq and Redis. Solid understanding of RESTful API design, JSON serialization, and authentication (e.g., JWT, SSO). Hands-on experience with AWS services and containerised deployments (Docker). Experience troubleshooting ...

Senior Node/AWS Developer

Hiring Organisation
Method-Resourcing
Location
City of London, London, United Kingdom
Employment Type
Permanent
Salary
£80,000
impact The skills and experience my client are looking for: 5+ years of experience in software engineering, with expertise in Node.js and REST API design. Strong knowledge of AWS and serverless architecture. Strong experience with TypeScript, ensuring clean, efficient, and maintainable code. Experience with CI/CD pipelines using ...

AI Platform Engineer

Hiring Organisation
The Portfolio Group
Location
London, Castle Baynard, United Kingdom
Employment Type
Permanent
owning the cloud-native platform that underpins conversational AI and generative AI products at scale. Sitting at the core of AI delivery, you will design, build, and operate the runtime, infrastructure, and operational layers supporting RAG pipelines, LLM orchestration, vector search, and evaluation workflows across AWS and Databricks. Working … platform powering conversational assistants and generative AI products. Build, operate, and optimise RAG and LLM-backed services, improving latency, reliability, and cost. Design and run cloud-native AI services across AWS and Databricks, including ingestion and embedding pipelines. Scale and operate vector search infrastructure (Weaviate, OpenSearch, Algolia, AWS Bedrock ...

Product Engineer

Hiring Organisation
Affinity Labs
Location
City of London, London, United Kingdom
full-stack product delivery, from infrastructure and AI integrations through to React/React Native interfaces, collaborating closely with founders, creators, product, and design to turn lean specs into scalable, user-loved software. We’re looking for a strong generalist with backend depth and real mobile experience. Responsibilities Implement … mobile + web frontend → APIs → data models → integrations) while maintaining quality and velocity. Build React Native mobile apps and shared component systems across products. Design and ship scalable backend services (APIs, integrations, AI workflows). Run tight build → test → iterate → ship loops; provide realistic estimates and surface blockers early. ...

Senior Java Engineer – Reactive

Hiring Organisation
Fynity
Location
City of London, London, United Kingdom
senior individual-contributor role within a high-performing engineering team, building asynchronous, message-driven systems designed for scale, resilience, and near-zero downtime. Design and implement high-throughput, low-latency systems processing millions of real-time payment events Build event-driven architectures using modern Java and reactive frameworks Work … extensively with non-blocking I/O, asynchronous flows, back-pressure, and concurrency Contribute to system and API design, focusing on scalability, fault tolerance, and observability Collaborate closely with architects, engineers, and client teams across Europe Operate in Agile environments (Scrum/Kanban) with a strong engineering culture ...

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 ...

Core Software Engineer

Hiring Organisation
Aries Global
Location
City of London, London, United Kingdom
seasoned technical leaders. What matters is how you think, build, and ship. You'll take end-to-end ownership of features from architecture design to measurable impact — shipping code that directly moves revenue, retention, or product velocity. You'll design clean abstractions in ambiguous environments, evolve systems into … . We care about outcomes, not activity. What We're Looking For You've built and shipped real systems. You understand data modelling, API design, system trade-offs, testing, and reliability. You know how to move fast without creating chaos. You're strong in at least one modern ...

Lead Full Stack Developer

Hiring Organisation
G.R.E. Recruitment Limited
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£95,000
Start Up - Smart Living Platform Fully Remote - Must be UK based £85,000 - £95,000 + Stock Options (DOE) Essential Exp: Laravel, Flutter, SaaS, API Design, MySQL/PostgreSQL/MariaDB G.R.E. Recruitment is DELIGHTED and EXCITED to partner with an exciting UK based PropTech Start-Up company … defining technical standards, scalability strategy, and product direction across the technical ecosystem. In this role you will: Own and evolve a Laravel-based REST API Develop and maintain a Flutter mobile application (iOS & Android) Design and implement secure, multi-tenant architecture Establish clean coding standards and engineering best ...

Ruby on Rails Engineer

Hiring Organisation
Rise Technical Recruitment
Location
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 ...