26 to 47 of 47 API Design Jobs in London

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

Hiring Organisation
Transreport
Location
London Area, 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 ...

Senior Node/AWS Developer

Hiring Organisation
Method Resourcing
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£80,000 per annum
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 ...

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 ...

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 ...

Backend Engineer

Hiring Organisation
Searchability
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£50,000 - £75,000 per annum
architecture and deployments Exposure to cutting-edge AI and real-time data systems Fast-paced, collaborative engineering environment THE BACKEND ENGINEER ROLE: You'll design, build, and maintain high-performance APIs using Python and FastAPI, working with large volumes of live sports data. The systems are real-time … subject to required skills) your application to our client in conjunction with this vacancy only. KEY SKILLS Python, FastAPI, PostgreSQL, AWS, Docker, Backend Development, API Design, Real-Time Systems, Software Engineering, Sports Data ...

Back End Developer

Hiring Organisation
NearTech Search
Location
City of London, London, United Kingdom
influence architectural decisions at a critical stage of growth. The Senior Backend Engineer (Full Stack, backend-leaning) will take ownership of complex backend REST API Services and deliver scalable systems using TypeScript and Node.js . You will closely with Product, Engineering and Operations, working alongside the Lead Engineer … refine technical direction, improve delivery standards and elevate system reliability. The Senior Backend Engineer (Full Stack, backend-leaning) will... • Design and maintain scalable Node.js/TypeScript services and REST APIs • Own backend initiatives end-to-end, from architecture to rollout • Strengthen testing strategy across unit and integration layers • Improve ...

iOS Developer

Hiring Organisation
Expedia Group
Location
City of London, London, United Kingdom
architectural direction, influencing engineering standards, and shaping the evolution of AI-enabled capabilities across the mobile platform. In this role, you will: 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 and API designs, including effective data modelling to support complex business requirements. Drive cross-functional collaboration to define, develop, and ship impactful features, ensuring alignment with organisational goals and technical strategy. Champion best practices in software engineering, testability, and maintainability through code reviews and mentoring. Safely integrate ...

Product Engineer

Hiring Organisation
SR2 | Socially Responsible Recruitment | Certified B Corporation™
Location
City of London, London, United Kingdom
product managers, engineers, and end users to understand new customer use cases Turn those use cases into reusable platform capabilities , rather than bespoke solutions Design and build scalable data models, workflows, and abstractions that work across multiple customers Build and extend AI-enabled workflows as part of the core … fully specified Nice to Have (Not Essential) Experience with modern data platforms (e.g. Databricks, Snowflake, dbt, Airflow, Foundry) Some exposure to backend development or API design TypeScript experience Familiarity with enterprise systems (ERP, CRM, etc.) Exposure to AI-enabled systems , generative AI, or workflow orchestration ...

Mobile Engineer

Hiring Organisation
Expedia Group
Location
London Area, United Kingdom
Senior Mobile Engineer (Android) 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. Why Join … with a growth mindset. We value our team culture and work together from the office three times a week. In this role, you will: Design, build, and maintain advanced Android applications with a focus on scalable architecture and robust performance. Collaborate with cross-functional teams to deliver high-quality ...

Full Stack Engineer

Hiring Organisation
Intellect Group
Location
London Area, United Kingdom
operations teams and field contractors across the UK. You will work on modern web applications using Python, Django, HTML, HTMX and React, contributing to API design, system architecture and end to end feature delivery. This is a high ownership role suited to someone comfortable working autonomously ...

Full Stack Engineer

Hiring Organisation
Intellect Group
Location
City of London, London, United Kingdom
platform used by clients, operations teams and field contractors across the UK. You will work across Python and Django on the backend, contributing to API design, system architecture and end to end feature delivery. The environment includes modern web technologies such as React and HTMX, supported ...

Lead AI Engineer

Hiring Organisation
Aturiya AI
Location
London Area, United Kingdom
Next.js. You've worked with LLMs in production - prompt engineering, evals, handling non-determinism. Not just tutorials. You have taste. You care about UX, API design, code structure - not because someone told you to, but because sloppy work bothers you. You default to action. When something's unclear ...

Mulesoft Developer

Hiring Organisation
Bridge Recruitment UK Limited
Location
Central London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£75,000
Salesforce MuleSoft Developer (Hybrid Role) Were looking for an experienced Salesforce MuleSoft Developer to design, build, and maintain integrations between Salesforce and external systems. Youll work closely with cross-functional teams to deliver scalable, high-performance integration solutions aligned with business needs. What youll do: Design, develop, test … 3+ years Salesforce experience Strong background in software development and OOP Hands-on MuleSoft & Salesforce integration experience MuleSoft certification(s) Solid understanding of API design and integration best practices Bachelors degree in Computer Science, Engineering, or related field Salesforce ecosystem experience is a strong plus. ...

Senior / Founding Full Stack Developer

Hiring Organisation
G.R.E. Recruitment Limited
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP 95,000 Annual
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 ...

Android Developer

Hiring Organisation
Expedia Group
Location
London Area, United Kingdom
setting architectural direction, influencing engineering standards, and shaping the evolution of AI-enabled capabilities across the mobile platform. In this role, you will: Architect, design, and deliver advanced Android mobile solutions, ensuring scalability, performance, and maintainability across Expedia Group’s travel platforms. Lead technical direction for multi-service … quality, and knowledge sharing. Safely integrate and operate AI/ML-enabled solutions that improve mobile user experiences and business outcomes. Collaborate with product, design, and engineering stakeholders to deliver innovative mobile features and drive technical strategy across the organisation. Minimum Qualifications: Bachelor’s degree in Computer Science ...

JavaScript TypeScript Engineer | D3 | SVG | Canvas | Data Visualisation | 2D Graphics

Hiring Organisation
techstack Recruitment
Location
City of London, London, United Kingdom
typical frontend role. You’ll be working at the heart of a graphics and visualisation engine — solving problems around rendering, performance, correctness, and API design. Why engineers take this role You work on the hard stuff This is core library engineering: rendering engines, chart primitives, 2D graphics, and public … Strong JavaScript and/or TypeScript fundamentals Experience with 2D graphics (Canvas, SVG, Processing, or similar) Solid grounding in data structures, algorithms, and software design Experience with at least one statically typed language Working understanding of basic linear algebra Apply in confidence. Company details shared at first conversation. ...