26 to 46 of 46 API Design Jobs in London

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 ...

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 ...

Technical Architect

Hiring Organisation
Tria Recruitment
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£85,000
ensuring solutions are secure, scalable and aligned with the organisation's long-term technology strategy. Key Responsibilities Define and govern technical architecture standards and design principles Provide hands-on architectural leadership across cloud platforms, integrations and development Lead architecture reviews and technical design decisions Support engineering teams with … Senior Developer Strong experience with Microsoft Azure cloud platforms Experience working with Dynamics 365/CRM environments Knowledge of cloud architecture, integrations and API design Familiarity with DevOps and modern engineering practices Strong communication skills and ability to engage both technical and non-technical stakeholders Benefits Salary ...

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 ...

Solutions Architect (Microsoft stack)

Hiring Organisation
Experis
Location
London, United Kingdom
Employment Type
Permanent
Salary
£80,000
Architect to support major transformation work across organisations digital health platform roadmap. The team needs a technology-agnostic, Azure-centred solution architect who can design, assure, and guide the build of new healthcare-aligned digital products over the next 12-18 months. The role will work across Azure, Logic … Apps, Power Apps/Power Pages, Mircosoft Dynamics, API integration, orchestration layers, SaaS/PaaS selections , and will play a key part in enabling shift towards a standard Microsoft platform . This person will be responsible for end-to-end architectural oversight , ensuring guardrails, security, and governance are correctly ...

Tech Lead/Solution Architect (Energy/Utilities)

Hiring Organisation
Vallum Associates Limited
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
Up to £620 per day Inside IR35
London, UK - Hybrid Key Responsibilities : Design end-to-end solution architecture for energy or utility platforms and digital services. Define technical standards, APIs, integrations, and interoperability frameworks across systems. Assess technical solutions, risks, and architecture suitability for complex distributed platforms. Lead delivery of cloud-native, microservices-based platforms supporting … Technical Architecture roles. Background working in Energy/Utilities/Retail Energy markets. Experience designing cloud-native and microservices architectures. Strong knowledge of API design, system integration and interoperability standards. Experience managing data architecture, processing pipelines and platform scalability. ...

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 ...

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 ...

Senior Software Developer (Full Stack)

Hiring Organisation
Reed
Location
Holborn, London, England, United Kingdom
Employment Type
Full-Time
Salary
£80,000 - £95,000 per annum, Inc benefits
commercial software development experience. Proven success in high-performing engineering teams within fast-paced environments. Deep expertise in: Python (Django, Flask, or FastAPI) PostgreSQL (design, optimisation, maintenance) Containerisation (Docker/Kubernetes) Event-driven architecture (Kafka/RabbitMQ) Desirable experience includes: TypeScript/JavaScript (NextJS, NodeJS, Tailwind) Terraform and DevOps … practices Experience in building and scaling SaaS platforms in production. Strong background in software architecture, microservices, and API design. Hands-on experience with AWS platform. Excellent communication skills, capable of motivating and aligning technical teams. Experience with AI tools, APIs, or ML pipelines is highly desirable. Bonus: Exposure ...

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
City of London, London, 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 ...

Lead AI Engineer

Hiring Organisation
Aturiya AI
Location
City of London, London, 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 ...

Lead Full Stack Developer

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

Lead Software Engineer

Hiring Organisation
Pro Trader LLC
Location
City of London, London, United Kingdom
Web3 space, our roadmap includes future decentralised integrations – so an interest or background in blockchain technology is highly desirable. Key Responsibilities Lead the software design and development of our next-generation trading engine. Oversee a codebase primarily written in Kotlin, with additional components in Python, Flutter, and SQL. Implement … robust security protocols and cryptographic solutions to protect financial transactions and user data. Design and maintain high-performance financial algorithms. Collaborate with our international platform development and product teams to deploy services onto our cloud-agnostic developer platform and maintain cyber security. Mentor other engineers, fostering a culture ...

Senior Software Engineer | Charts Engineer | Data Visualisation | JavaScript | TypeScript

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. ...