276 to 300 of 365 API Design Jobs in the UK

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 ❯

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 ❯

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 (<40s) 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 ❯

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 ❯

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 ❯

scale, regulated environments - ideally in Investment, Asset or Wealth Management. Solid experience in building and deploying frontend applications in React or React Native with hands-on knowledge of secure API design and authentication services. Experience in Java and Spring Boot, or iOS (Swift) or Android (Kotlin) along with exposure to Figma and Vercel is a big plus. Capable More ❯

Strong ability to integrate with REST APIs, manage secure authentication flows, and handle offline scenarios Basic understanding of backend systems (e.g. Node.js, AWS) to debug issues and contribute to API design discussions Proficient in Git, with best practices for branching, tagging, and changelogs Comfortable using tools like Jira, TestRail, and writing technical documentation Experience working in cross-functional 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 ❯