1 to 25 of 32 API Design Jobs in London

Open Stack, Salesforce & React Native Specialists - London Atrium EME

Hiring Organisation
Atrium Global
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
Up to £550 per day
12+mths contract, 2 days onsite/3 days remote, PAYE/Umbrella options. Open Stack/Salesforce & ReactNative - Salesforce, ReactNative (Web), Java, TDD, RESTful API design & build, OAS/YAML, Unit Testing, GitLab, CI/CD Pipelines, SonarQube, Veracode, Jira, Confluence Open Stack BA - Salesforce, ReactNative (Web), Java … RESTful API design & build, OAS/YAML, Unit Testing, GitLab, CI/CD Pipelines, Jira, Confluence API Developer - Java, TDD, RESTful API design & build, OAS/YAML, GitLab, CI/CD Pipelines, Java Database-Hibernate/JPA, SonarQube, Veracode, Jira, Confluence Click Apply ...

Application Architect

Hiring Organisation
Experis
Location
Croydon, London, United Kingdom
Employment Type
Contract
Contract Rate
£710 - £735/day
site Due to the urgency and sensitivity of the work, active SC Clearance is mandatory . Responsibilities As an Application Architect, you will: Design and lead delivery of scalable, high-performance application architectures Define and apply modern application architecture patterns , including microservices, event-driven architectures, and SOA Support monolith … microservices transformation initiatives where required Architect cloud-native applications across AWS, Azure, and/or GCP Design API strategies , integration patterns, and messaging-based solutions Ensure strong alignment with application lifecycle management , CI/CD pipelines, and DevOps practices Work closely with platform and engineering teams to align ...

Mobile Engineer (Android)

Hiring Organisation
Captur
Location
City of London, London, United Kingdom
pressure; make frame-time and latency predictable across device classes Define and monitor SDK health metrics at scale (crashes, ANRs, error rates, perf envelopes) API design and developer experience Design clear, stable, Kotlin-first public APIs (versioned, well-documented, testable) Implement best practices for networking, auth … fixes and verify via dashboards Provide concise developer-facing change notes/migration snippets to the Solutions Engineer for release notes Roadmap contribution Co-design the next generation of the Android Captur SDK for release at the end of Q2 Champion performance budgets and device-class targets during planning ...

Backend Engineer (AI Platform) - London

Hiring Organisation
Revax
Location
London, England, United Kingdom
Role We’re hiring a Backend Engineer to build the core infrastructure behind Revax’s AI-native platform for professional services. You’ll design, optimise, and scale the systems that power multi-agent drafting, knowledge graphs, and auditable AI workflows used by accountants, tax advisors, and consultants at leading … graphs, and real-world enterprise workflows. What You’ll Do Build & own core backend systems · Build and optimise databases for complex, real-world data · Design and implement APIs using FastAPI for AI workflows and product features · Build and scale LangGraph-based multi-agent systems with checkpointing, retries, and observability ...

Senior Developer - AI Operations (Python/Golang)

Hiring Organisation
Sky
Location
TW75QD, Syon, Greater London, United Kingdom
Employment Type
Permanent
supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

Solutions Architect

Hiring Organisation
Euro Car Parks
Location
Central London, London, United Kingdom
Employment Type
Permanent
Ireland providing specialist services to a wide range of blue-chip clients. The role We are seeking technical polyglots who enjoy both technical architectural design, hands-on coding and peer reviews, though also like the idea of the equally important social/client-facing aspect of the role. … development architecture as well as supporting business analysts and product owners in planning and story-mapping for new development. You will act as technical design authority (TDA) for delivery of technical stories and produce technical documentation artefacts to support the delivery process. Main Responsibilities Duties will include: The design ...

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 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 ...

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 ...

SAP BTP Lead

Hiring Organisation
DXC
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
Youll collaborate with business and technical teams to drive innovation, modernize architectures, and maximize value from SAPs cloud technologies. What Youll Do: Lead architecture, design, and implementation of solutions using SAP BTP services such as SAP Build, Integration Suite, Event Mesh, AI Core, and HANA Cloud. Define clean-core … Guide teams in building custom apps, workflows, automations, and side-by-side extensions using CAP/RAP and low-code tools. Own integration and API strategies leveraging BTP Integration Suite (APIs, OData, REST/SOAP, event-driven patterns). Provide technical leadership, mentoring developers and ensuring adherence to coding ...

Junior Back-end Engineer

Hiring Organisation
ivee
Location
London Area, 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 ...

Senior PHP Full Stack Software Engineer - Sustainability

Hiring Organisation
RecruitmentRevolution.com
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP 70,000 - 80,000 Annual
want to expand this further - so you ll help define best practice for AI-enabled engineering across the team. Key Responsibilities: • Lead the design, build and maintenance of custom Moodle plugins, themes and core feature enhancements • Write high-quality, secure, reusable PHP and deliver robust front-end experiences • Architect … across application + infrastructure layers and drive resolution • Lead performance optimisation and scalability improvements • Ensure compliance with accessibility standards, GDPR, and data protection by design • Strengthen QA processes and data integrity (including release readiness) Collaboration & Stakeholder Management: • Work closely with product and design to shape solutions (not just ...

Senior PHP Full Stack Software Engineer - Sustainability

Hiring Organisation
RecruitmentRevolution.com
Location
EC1V, Bunhill, Greater London, Old Street, United Kingdom
Employment Type
Permanent
Salary
£70000 - £80000/annum + Benefits
want to expand this further - so you’ll help define best practice for AI-enabled engineering across the team. Key Responsibilities: • Lead the design, build and maintenance of custom Moodle plugins, themes and core feature enhancements • Write high-quality, secure, reusable PHP and deliver robust front-end experiences • Architect … across application + infrastructure layers and drive resolution • Lead performance optimisation and scalability improvements • Ensure compliance with accessibility standards, GDPR, and data protection by design • Strengthen QA processes and data integrity (including release readiness) Collaboration & Stakeholder Management: • Work closely with product and design to shape solutions (not just ...

Senior Full Stack Engineer (Team Lead)

Hiring Organisation
Futuria
Location
London Area, 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 ...

Backend Engineer – Build Scalable, High‐Impact Financial Infrastructure

Hiring Organisation
Albert Bow
Location
London Area, United Kingdom
+ mobile applications Building and maintaining high‐performance APIs and distributed microservices Solving problems around scalability, reliability, security, and automation Working with modern API protocols including GraphQL and gRPC Enhancing the platform that connects both traditional and on‐chain financial services Must‐have experience: Strong backend engineering background with …/or Golang Solid understanding of microservices, event‐driven systems & distributed architecture Strong knowledge of PostgreSQL and/or Redis Understanding of web semantics, API design & backend web standards Proficiency with Git and version control workflows Experience with CI/CD, build automation and modern engineering pipelines Excellent ...

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 ...

Senior Engineering Manager B2C

Hiring Organisation
Client Server
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
systems are scalable, reusable and clearly owned. You'll establish modern engineering standards across the full SDLC, including CI/CD, automated testing, observability, API design, security and operational readiness, enabling teams to deliver quickly and safely. You'll lead architecture and design reviews, make pragmatic technical … With end-to-end accountability for engineering domains, you'll define service expectations, KPIs and reliability targets while ensuring operational excellence. Collaborating with Product, Design, Data, AI and Operations, you'll translate business priorities into clear engineering roadmaps and guide stakeholders on feasibility and trade-offs, owning delivery outcomes ...

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 (Spring WebFlux)

Hiring Organisation
Fynity
Location
London Area, 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 ...

Senior / Founding Full Stack Developer

Hiring Organisation
G.R.E. Recruitment Limited
Location
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 ...

Mobile App Experience Layer Engineer

Hiring Organisation
ARM
Location
Stratford, London, United Kingdom
Employment Type
Contract
Contract Rate
£508 - £548/day Inside IR35
Experience - Java/Kotlin with Spring and Spring Boot - Google Cloud Platform (Cloud Run, Pub/Sub, Secret Manager) - Observability tools (Grafana, Splunk) - REST API design - TDD, pair programming, mobbing - Strong communication and mentoring - Git Preferred Experience - DevOps/CI/CD - Load & performance testing - Mobile integration experience ...

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 ...

Application Solution Architect

Hiring Organisation
Hays Technology
Location
City of London, London, United Kingdom
Employment Type
Contract
Contract Rate
£700 - £750/day £750pd inside IR35
Your new company Tier 1 Financial Services Client Your new role This role is for someone who can design and guide thebuilding of complex payment systems, making sure they follow regulations, use modern tech, and meet business needs. It requires deep banking knowledge, strong technical architecture skills, and excellent … PSD3, Open Banking, SEPA rulebooks, UK Payment Regulator mandates, ECB/TARGET services updates, ISO 20022 migration, and AML/CTF regulations. Proficiency in API Design, microservices, and integration platforms. Modernprogramming languages (Java, .NET, Python, JavaScript frameworks) What you'll get in return An exciting opportunity to join ...

Artificial Intelligence Engineer

Hiring Organisation
HireWise
Location
City of London, London, United Kingdom
edge AI functionality across a flagship cybersecurity platform, building scalable, performant systems that harness the power of data, ML models, and infrastructure. Key Responsibilities: Design, develop, and deploy production-grade ML/AI features — from data prep and model training to inference APIs and monitoring. Integrate and scale LLMs … PyTorch and scikit-learn . Hands-on experience with state-of-the-art foundation models, embeddings, and RAG. Strong knowledge of cloud computing, microservices, API design, and event-driven architectures. Experience with Jupyter notebooks for data exploration and model iteration. About You: You are driven, empathetic, and thrive ...