API Design Jobs in England

276 to 300 of 348 API Design Jobs in England

Founding Engineer (Backend)

City of London, London, United Kingdom
Affinity Labs
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 ❯
Posted:

Founding Engineer (Backend)

london, south east england, united kingdom
Affinity Labs
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 ❯
Posted:

Founding Engineer (Backend)

slough, south east england, united kingdom
Affinity Labs
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 ❯
Posted:

Founding Engineer (Backend)

london (city of london), south east england, united kingdom
Affinity Labs
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 ❯
Posted:

Founding React Native Engineer (Full-Stack)

London Area, United Kingdom
Affinity Labs
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 ❯
Posted:

Founding React Native Engineer (Full-Stack)

City of London, London, United Kingdom
Affinity Labs
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 ❯
Posted:

Founding React Native Engineer (Full-Stack)

london, south east england, united kingdom
Affinity Labs
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 ❯
Posted:

Founding React Native Engineer (Full-Stack)

slough, south east england, united kingdom
Affinity Labs
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 ❯
Posted:

Founding React Native Engineer (Full-Stack)

london (city of london), south east england, united kingdom
Affinity Labs
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 ❯
Posted:

eFX Engineer

City of London, London, United Kingdom
Sanderson Recruitment
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 ❯
Employment Type: Permanent
Posted:

eFX Engineer

London, South East, England, United Kingdom
Sanderson
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 ❯
Employment Type: Full-Time
Salary: £84,000 - £160,000 per annum
Posted:

Full Stack Engineer

Birmingham, England, United Kingdom
Hybrid / WFH Options
Propel
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 ❯
Posted:

Staff Frontend Developer - Outside IR35 Contract

City of London, London, United Kingdom
Burns Sheehan
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 ❯
Posted:

Staff Frontend Developer - Outside IR35 Contract

London Area, United Kingdom
Burns Sheehan
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 ❯
Posted:

Staff Frontend Developer - Outside IR35 Contract

london, south east england, united kingdom
Burns Sheehan
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 ❯
Posted:

Staff Frontend Developer - Outside IR35 Contract

london (city of london), south east england, united kingdom
Burns Sheehan
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 ❯
Posted:

Staff Frontend Developer - Outside IR35 Contract

slough, south east england, united kingdom
Burns Sheehan
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 ❯
Posted:

Senior Software Engineer - Unified Client Experience (UCX)

England, United Kingdom
Hargreaves Lansdown PLC
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 ❯
Employment Type: Permanent
Salary: GBP Annual
Posted:

Senior Mobile Engineer

London, United Kingdom
Skin Analytics Ltd
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 ❯
Employment Type: Permanent
Salary: GBP Annual
Posted:

Software Engineer

Suffolk, England, United Kingdom
Oscar Technology
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 ❯
Employment Type: Contractor
Rate: £375 - £425 per day
Posted:

Software Engineer

Suffolk, East Anglia, United Kingdom
Oscar Associates (UK) Limited
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 ❯
Employment Type: Contract
Rate: £375 - £425 per day
Posted:

Embedded Software Developer

Bristol, United Kingdom
Hybrid / WFH Options
Smartbox Assistive Technology
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 ❯
Employment Type: Permanent
Salary: £50000 - £60000/annum
Posted:

Embedded Software Developer

Bristol, Gloucestershire, United Kingdom
Hybrid / WFH Options
Smartbox Assistive Technology
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 ❯
Employment Type: Permanent
Salary: GBP 50,000 - 60,000 Annual
Posted:

Embedded Software Developer

Bristol, Avon, South West, United Kingdom
Hybrid / WFH Options
Smartbox Assistive Technology
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 ❯
Employment Type: Permanent, Work From Home
Salary: £60,000
Posted:

Python Developer

Sheffield, England, United Kingdom
Hybrid / WFH Options
NearTech Search
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 ❯
Posted:
API Design
England
10th Percentile
£52,500
25th Percentile
£61,250
Median
£75,000
75th Percentile
£98,125
90th Percentile
£126,250