226 to 250 of 282 API Design Jobs in the UK excluding London

join them at inception of the project. This is a rare opportunity to influence best practices from the ground up, working directly with the FX Options trading desk to design and build a system that handles large volumes of market data in near real-time. Key Responsibilities: Design and develop scalable, high-performance systems using modern C# .Net … with a strong grasp of recent language features and .NET ecosystem Proven experience working with FX Options trading systems or directly with Options traders Solid understanding of systems integration, API design, and microservices architecture Experience handling large-scale market data in low-latency or real-time environments Hands-on experience converting monolithic applications into microservices Desirable: Exposure to More ❯

Stack or Backend Developer to play a key role in shaping the backend of our next-generation B2C platform. You’ll work closely with our front-end team to design and deliver robust, scalable APIs and infrastructure that power our consumer experience. What You’ll Do: Develop and maintain production-grade APIs and backend systems using Node.js. Leverage AI … and security for scale. Collaborate with front-end engineers to integrate APIs seamlessly. What We’re Looking For: Extensive experience building high-traffic consumer applications. Strong understanding of RESTful API design, database optimization, and security. Proven AI-assisted development workflow. Ability to work autonomously within established technical frameworks. Nice to Have: React/Next.js, Azure, Payload CMS, microservices More ❯

Stack or Backend Developer to play a key role in shaping the backend of our next-generation B2C platform. You’ll work closely with our front-end team to design and deliver robust, scalable APIs and infrastructure that power our consumer experience. What You’ll Do: Develop and maintain production-grade APIs and backend systems using Node.js . Leverage … security for scale. Collaborate with front-end engineers to integrate APIs seamlessly. What We’re Looking For: Extensive experience building high-traffic consumer applications . Strong understanding of RESTful API design, database optimization, and security . Proven AI-assisted development workflow. Ability to work autonomously within established technical frameworks. Nice to Have: React/Next.js, Azure, Payload CMS More ❯

Stack or Backend Developer to play a key role in shaping the backend of our next-generation B2C platform. You’ll work closely with our front-end team to design and deliver robust, scalable APIs and infrastructure that power our consumer experience. What You’ll Do: Develop and maintain production-grade APIs and backend systems using Node.js . Leverage … security for scale. Collaborate with front-end engineers to integrate APIs seamlessly. What We’re Looking For: Extensive experience building high-traffic consumer applications . Strong understanding of RESTful API design, database optimization, and security . Proven AI-assisted development workflow. Ability to work autonomously within established technical frameworks. Nice to Have: React/Next.js, Azure, Payload CMS More ❯

Stack or Backend Developer to play a key role in shaping the backend of our next-generation B2C platform. You’ll work closely with our front-end team to design and deliver robust, scalable APIs and infrastructure that power our consumer experience. What You’ll Do: Develop and maintain production-grade APIs and backend systems using Node.js . Leverage … security for scale. Collaborate with front-end engineers to integrate APIs seamlessly. What We’re Looking For: Extensive experience building high-traffic consumer applications . Strong understanding of RESTful API design, database optimization, and security . Proven AI-assisted development workflow. Ability to work autonomously within established technical frameworks. Nice to Have: React/Next.js, Azure, Payload CMS More ❯

fast to take things to the next level. Youll join as a Senior Backend Engineer , taking ownership of complex Python/Django services that power enterprise decarbonisation. Expect to design elegant APIs, tackle data-heavy challenges, and collaborate closely with sustainability experts and product teams. What makes this special? High-performance engineering team smart, passionate, and collaborative Big mission …/CD, and plenty of greenfield challenges Youll be a great fit if you bring: 7+ years backend experience (Python expertise essential) Strong knowledge of Django (or similar) and API design Experience scaling apps, with an eye for performance and reliability A proactive, problem-solving mindset and love for collaboration Enjoy a collaborative, chic, and modern office environment More ❯

in tight cycles. This is an early-stage, hands-on role with significant autonomy and responsibility to drive backend product development, collaborating closely with founders, creators, and product/design to turn lean specs into reliable, scalable services. Responsibilities Implement features end-to-end on the backend (APIs → data models → integrations) and maintain quality while moving fast. Run tight … safety guardrails). Essential Requirements 2–4+ years building production backends/services , with shipped work and clear ownership. Strong Python (FastAPI) and database skills ( PostgreSQL/MongoDB ); solid API design fundamentals. Familiarity with AWS serverless patterns and Docker for bespoke services; basic CI/CD concepts. Comfortable with Redis (caching/sessions) and common queue/messaging More ❯

in tight cycles. This is an early-stage, hands-on role with significant autonomy and responsibility to drive backend product development, collaborating closely with founders, creators, and product/design to turn lean specs into reliable, scalable services. Responsibilities Implement features end-to-end on the backend (APIs → data models → integrations) and maintain quality while moving fast. Run tight … safety guardrails). Essential Requirements 2–4+ years building production backends/services , with shipped work and clear ownership. Strong Python (FastAPI) and database skills ( PostgreSQL/MongoDB ); solid API design fundamentals. Familiarity with AWS serverless patterns and Docker for bespoke services; basic CI/CD concepts. Comfortable with Redis (caching/sessions) and common queue/messaging More ❯

in tight cycles. This is an early-stage, hands-on role with significant autonomy and responsibility to drive backend product development, collaborating closely with founders, creators, and product/design to turn lean specs into reliable, scalable services. Responsibilities Implement features end-to-end on the backend (APIs → data models → integrations) and maintain quality while moving fast. Run tight … safety guardrails). Essential Requirements 2–4+ years building production backends/services , with shipped work and clear ownership. Strong Python (FastAPI) and database skills ( PostgreSQL/MongoDB ); solid API design fundamentals. Familiarity with AWS serverless patterns and Docker for bespoke services; basic CI/CD concepts. Comfortable with Redis (caching/sessions) and common queue/messaging More ❯

and iterating across tight cycles. This is an early-stage, hands-on role with significant autonomy and responsibility to drive product development cycles, collaborating closely with founders, creators, and design to turn lean specs into live products. Responsibilities Implement features end-to-end (React Native → APIs → data) and maintain quality while moving fast. Run tight build, test, iterate, ship … 6+ years building production mobile apps (React Native), with shipped apps. Strong React Native proficiency (Expo experience strongly preferred). Full-stack capability: backend in Python (FastAPI) and databases; API design; basic cloud infra familiarity. Startup mindset: high ownership, pace, ambiguity; willing to burn the midnight oil when needed. Growth mindset & flexibility: open to feedback; not rigid about More ❯

and iterating across tight cycles. This is an early-stage, hands-on role with significant autonomy and responsibility to drive product development cycles, collaborating closely with founders, creators, and design to turn lean specs into live products. Responsibilities Implement features end-to-end (React Native → APIs → data) and maintain quality while moving fast. Run tight build, test, iterate, ship … 6+ years building production mobile apps (React Native), with shipped apps. Strong React Native proficiency (Expo experience strongly preferred). Full-stack capability: backend in Python (FastAPI) and databases; API design; basic cloud infra familiarity. Startup mindset: high ownership, pace, ambiguity; willing to burn the midnight oil when needed. Growth mindset & flexibility: open to feedback; not rigid about More ❯

and iterating across tight cycles. This is an early-stage, hands-on role with significant autonomy and responsibility to drive product development cycles, collaborating closely with founders, creators, and design to turn lean specs into live products. Responsibilities Implement features end-to-end (React Native → APIs → data) and maintain quality while moving fast. Run tight build, test, iterate, ship … 6+ years building production mobile apps (React Native), with shipped apps. Strong React Native proficiency (Expo experience strongly preferred). Full-stack capability: backend in Python (FastAPI) and databases; API design; basic cloud infra familiarity. Startup mindset: high ownership, pace, ambiguity; willing to burn the midnight oil when needed. Growth mindset & flexibility: open to feedback; not rigid about More ❯

Manchester)Up to £160,000 + benefits/Bonus Join a leading financial technology and trading organisation driving innovation in electronic markets. As an eFX Software Engineer, you'll design and deliver high-performance, low-latency trading solutions that underpin mission-critical systems. This role offers the chance to work on cutting-edge technology where speed, scalability, and resilience … are key. About the Role Lead the design and development of secure, high-performance eFX systems Define and evolve Java patterns and techniques optimised for ultra-low latency (<40μs) Architect fault-tolerant, scalable trading systems Influence technical strategy, architecture, and product roadmaps Collaborate with multiple teams to deliver best-in-class E-trading platforms Ensure all solutions meet security … compliance, and performance standards What You'll Bring Strong experience in software engineering, architecture, and database design Expert-level Java development, including low-GC and lock-free patterns Proven background in FX trading systems, pricing, and risk management Deep understanding of CPU architecture, cache optimisation, and Linux performance tuning Expertise in networking and messaging (TCP, UDP, Multicast, FIX) Knowledge More ❯

a regular on-site presence (2 days onsite). Key Skills: - 5 years professional experience with TypeScript, JavaScript, and Node.js - Experience with frameworks such as React and NextJS, and API Design - Excellent communication skills with stakeholders and team members - Solid understanding of web development fundamentals and performance optimisation techniques - Ability to design, develop, test, deploy, and continuously More ❯

building something that lasts. What will you be doing: Own critical parts of the UI and its architecture, ensuring performance, usability, and resilience. Bring strong views on frontend patterns, API design, and how the frontend and backend fit together (they currently use Python, REST, GraphQL, microservices). What They Are Looking For: Proven expertise in JavaScript and React More ❯

building something that lasts. What will you be doing: Own critical parts of the UI and its architecture, ensuring performance, usability, and resilience. Bring strong views on frontend patterns, API design, and how the frontend and backend fit together (they currently use Python, REST, GraphQL, microservices). What They Are Looking For: Proven expertise in JavaScript and React More ❯

building something that lasts. What will you be doing: Own critical parts of the UI and its architecture, ensuring performance, usability, and resilience. Bring strong views on frontend patterns, API design, and how the frontend and backend fit together (they currently use Python, REST, GraphQL, microservices). What They Are Looking For: Proven expertise in JavaScript and React More ❯

ASAP What we're looking for: 4+ years' experience in software engineering (SaaS or start-up background preferred) Strong proficiency in Python and C#, with hands-on experience in API design and cloud architecture (Azure). Experience with Excel add-ins or Office JavaScript APIs is highly desirable. Exposure to vectorization, RAG (Retrieval-Augmented Generation), or AI-driven … Background or interest in commercial real estate technology. Self-starter with excellent communication skills and the ability to operate autonomously in a dynamic, growing business. What you'll do: Design & Develop: Build and maintain robust back-end services and APIs powering the company's automation suite. Integrate Smartly: Enhance and expand integrations across Microsoft 365 applications (Excel, Word, PowerPoint … . Architect Systems: Help design scalable, secure, and high-performance data infrastructure. Collaborate: Partner closely with the founding team and business stakeholders to translate complex workflows into elegant technical solutions. Lead by Example: Take control of the project, uphold code quality, and drive best practices across the stack. Shape the Future: Contribute to the long-term technical roadmap and More ❯

ASAP What we're looking for: 4+ years' experience in software engineering (SaaS or start-up background preferred) Strong proficiency in Python and C#, with hands-on experience in API design and cloud architecture (Azure). Experience with Excel add-ins or Office JavaScript APIs is highly desirable. Exposure to vectorization, RAG (Retrieval-Augmented Generation), or AI-driven … Background or interest in commercial real estate technology. Self-starter with excellent communication skills and the ability to operate autonomously in a dynamic, growing business. What you'll do: Design & Develop: Build and maintain robust back-end services and APIs powering the company's automation suite. Integrate Smartly: Enhance and expand integrations across Microsoft 365 applications (Excel, Word, PowerPoint … . Architect Systems: Help design scalable, secure, and high-performance data infrastructure. Collaborate: Partner closely with the founding team and business stakeholders to translate complex workflows into elegant technical solutions. Lead by Example: Take control of the project, uphold code quality, and drive best practices across the stack. Shape the Future: Contribute to the long-term technical roadmap and More ❯

one or more of the following languages: C, C++, Rust. 4+ years of experience in embedded software development in C. Knowledge of Computer Science fundamentals in data structures, algorithm design, problem-solving, and complexity analysis. Strong grounding in embedded software architecture, with a focus on maintainability, modularity, fault-tolerance and testability. Confident and experienced with automated testing, including unit … integration and system tests, mocking and automation frameworks. An understanding of API design and the creation of clear, stable abstractions for hardware/firmware interaction. Skilled at debugging in constrained environments and using hardware/software debugging tools. A proven track record of innovation and quality software development throughout the entire software product lifecycle. Ability to solve complex More ❯

one or more of the following languages: C, C++, Rust. 4+ years of experience in embedded software development in C. Knowledge of Computer Science fundamentals in data structures, algorithm design, problem-solving, and complexity analysis. Strong grounding in embedded software architecture, with a focus on maintainability, modularity, fault-tolerance and testability. Confident and experienced with automated testing, including unit … integration and system tests, mocking and automation frameworks. An understanding of API design and the creation of clear, stable abstractions for hardware/firmware interaction. Skilled at debugging in constrained environments and using hardware/software debugging tools. A proven track record of innovation and quality software development throughout the entire software product lifecycle. Ability to solve complex More ❯

one or more of the following languages: C, C++, Rust. 4+ years of experience in embedded software development in C. Knowledge of Computer Science fundamentals in data structures, algorithm design, problem-solving, and complexity analysis. Strong grounding in embedded software architecture, with a focus on maintainability, modularity, fault-tolerance and testability. Confident and experienced with automated testing, including unit … integration and system tests, mocking and automation frameworks. An understanding of API design and the creation of clear, stable abstractions for hardware/firmware interaction. Skilled at debugging in constrained environments and using hardware/software debugging tools. A proven track record of innovation and quality software development throughout the entire software product lifecycle. Ability to solve complex More ❯

ownership and contribute to software used in production from day one in a team where ideas are valued, shared, and acted upon where of benefit. What you’ll do Design, build, and maintain backend services and APIs in Python Collaborate with frontend and mobile engineers on end-to-end delivery Contribute to architecture and best-practice decisions across the … stack Write clean, maintainable, and well-tested code Essential experience Strong Python development skills Experience with Django (Flask/FastAPI are fine too) RESTful API design and integration Relational databases (PostgreSQL or similar) Git Worth noting: Whilst this is a backend role, you will need to have some light exposure to Javascript when required (purely for some ticketing More ❯

ownership and contribute to software used in production from day one in a team where ideas are valued, shared, and acted upon where of benefit. What you’ll do Design, build, and maintain backend services and APIs in Python Collaborate with frontend and mobile engineers on end-to-end delivery Contribute to architecture and best-practice decisions across the … stack Write clean, maintainable, and well-tested code Essential experience Strong Python development skills Experience with Django (Flask/FastAPI are fine too) RESTful API design and integration Relational databases (PostgreSQL or similar) Git Worth noting: Whilst this is a backend role, you will need to have some light exposure to Javascript when required (purely for some ticketing More ❯

Stack or Backend Developer to play a key role in shaping the backend of our next-generation B2C platform. You ll work closely with our front-end team to design and deliver robust, scalable APIs and infrastructure that power our consumer experience. Develop and maintain production-grade APIs and backend systems using Node.js . Leverage AI coding tools (GitHub … etc.) Optimize databases, authentication, and security for scale. Collaborate with front-end engineers to integrate APIs seamlessly. Extensive experience building high-traffic consumer applications . Strong understanding of RESTful API design, database optimization, and security . Proven AI-assisted development workflow. Nice to Have: React/Next.js, Azure, Payload CMS, microservices architecture. Contract: Full-time, initial term More ❯