1 to 25 of 40 Permanent API Development Jobs in the City of London

seeking a Full Stack Software Engineer to join our team! We're particularly looking for someone with strong Golang experience and with some experience of TypeScript and React frontend development . If you also have a knack for Kubernetes/containerisation, that's a significant bonus! In this role, you'll be a key contributor to the development … We're excited to have you contribute to our mission! Responsibilities : As a Safe Intelligence Full Stack Software Engineer, you will: Engineering of Golang-based backend systems , focusing on API development and integration. Contribute significantly to software development on our TypeScript-based frontend systems , primarily utilizing React to craft intuitive and highly functional user interfaces. Productize and … dataset management, verification workflows, and result/metric aggregations. Collaborate closely with our scientific and technical teams to interface with and containerize our PyTorch-based verification toolkit. Champion an API-first development approach to deliver feature-rich, versioned interfaces that support both our TypeScript user interface and Python-based SDKs. Develop and maintain Infrastructure as Code (IaC) and More ❯

seeking a Full Stack Software Engineer to join our team! We're particularly looking for someone with strong Golang experience and with some experience of TypeScript and React frontend development . If you also have a knack for Kubernetes/containerisation, that's a significant bonus! In this role, you'll be a key contributor to the development … We're excited to have you contribute to our mission! Responsibilities : As a Safe Intelligence Full Stack Software Engineer, you will: Engineering of Golang-based backend systems , focusing on API development and integration. Contribute significantly to software development on our TypeScript-based frontend systems , primarily utilizing React to craft intuitive and highly functional user interfaces. Productize and … dataset management, verification workflows, and result/metric aggregations. Collaborate closely with our scientific and technical teams to interface with and containerize our PyTorch-based verification toolkit. Champion an API-first development approach to deliver feature-rich, versioned interfaces that support both our TypeScript user interface and Python-based SDKs. Develop and maintain Infrastructure as Code (IaC) and More ❯

Data Engineer – Onsite (Central London) ⭐️ £50,000 – £55,000 + benefits ⭐️ 5 days onsite – Central London ⭐️ SQL, Python, API development ⭐️ Financial background preferred Join a leading investment management firm with a strong reputation for innovation in the financial sector. This is a fantastic opportunity to play a key role in building and maintaining robust data infrastructure supporting high … for a hands-on Data Engineer with solid SQL skills and experience in building and maintaining back-end APIs. SQL - strong experience essential. Python experience required. Proven experience in API development and maintenance. Previous experience within a financial services or investment management environment preferred. Strong analytical mindset and attention to detail. Excellent problem-solving and communication skills. More ❯

Data Engineer – Onsite (Central London) ⭐️ £50,000 – £55,000 + benefits ⭐️ 5 days onsite – Central London ⭐️ SQL, Python, API development ⭐️ Financial background preferred Join a leading investment management firm with a strong reputation for innovation in the financial sector. This is a fantastic opportunity to play a key role in building and maintaining robust data infrastructure supporting high … for a hands-on Data Engineer with solid SQL skills and experience in building and maintaining back-end APIs. SQL - strong experience essential. Python experience required. Proven experience in API development and maintenance. Previous experience within a financial services or investment management environment preferred. Strong analytical mindset and attention to detail. Excellent problem-solving and communication skills. More ❯

As a Senior Software Engineer, you will play a pivotal role in architecting and developing our next-generation web application and API. This role requires technical leadership, hands-on development, and mentoring of junior developers. You will drive the adoption of best practices, ensuring scalability, security, and performance. If you are passionate about software development, enjoy solving complex … tangible impact. This role will be eligible for visa sponsorship only for candidates that are already based in the UK. Key Responsibilities Technical Leadership: Lead the technical design and development of scalable, secure web applications and APIs, driving best practices across the development lifecycle. Architecture & Design: Oversee system architecture decisions, ensuring alignment with business goals and scalability requirements. … Mentorship: Mentor and guide junior developers, fostering a collaborative learning environment. API Development: Design and build RESTful API endpoints using NodeJS and Express, including detailed API documentation. Database Management: Design, optimize, and maintain complex SQL data models, ensuring efficient data structures, query performance, and reliability. Full-Stack Development: Develop responsive and performant front-end applications More ❯

As a Senior Software Engineer, you will play a pivotal role in architecting and developing our next-generation web application and API. This role requires technical leadership, hands-on development, and mentoring of junior developers. You will drive the adoption of best practices, ensuring scalability, security, and performance. If you are passionate about software development, enjoy solving complex … tangible impact. This role will be eligible for visa sponsorship only for candidates that are already based in the UK. Key Responsibilities Technical Leadership: Lead the technical design and development of scalable, secure web applications and APIs, driving best practices across the development lifecycle. Architecture & Design: Oversee system architecture decisions, ensuring alignment with business goals and scalability requirements. … Mentorship: Mentor and guide junior developers, fostering a collaborative learning environment. API Development: Design and build RESTful API endpoints using NodeJS and Express, including detailed API documentation. Database Management: Design, optimize, and maintain complex SQL data models, ensuring efficient data structures, query performance, and reliability. Full-Stack Development: Develop responsive and performant front-end applications More ❯

We are looking for a API solution architect who has had experience of dealing with Cognizant. Key Responsibilities • API Strategy & Leadership • Define and own the API delivery roadmap aligned with business and digital transformation goals. • Evangelize API-first architecture across the organization. • Lead and mentor a high-performing team of API developers, product owners, and … delivery managers. • Program & Delivery Management • Oversee the successful delivery of API projects from concept to production across multiple teams and geographies. • Establish KPIs and OKRs to measure performance, velocity, and reliability of API releases. • Ensure timely delivery while maintaining high quality, scalability, and security standards. • Architecture & Governance • Work closely with architects and platform teams to ensure consistent and … scalable API designs. • Establish API governance models, including versioning, security, documentation, and usage guidelines. • Ensure compliance with relevant standards (e.g., REST, GraphQL, OpenAPI, OAuth2). • Stakeholder & Partner Collaboration • Collaborate with internal business units, external partners, and clients to understand integration needs. • Act as the point of contact for strategic API integrations with partners and third-party platforms. More ❯

We are looking for a API solution architect who has had experience of dealing with Cognizant. Key Responsibilities • API Strategy & Leadership • Define and own the API delivery roadmap aligned with business and digital transformation goals. • Evangelize API-first architecture across the organization. • Lead and mentor a high-performing team of API developers, product owners, and … delivery managers. • Program & Delivery Management • Oversee the successful delivery of API projects from concept to production across multiple teams and geographies. • Establish KPIs and OKRs to measure performance, velocity, and reliability of API releases. • Ensure timely delivery while maintaining high quality, scalability, and security standards. • Architecture & Governance • Work closely with architects and platform teams to ensure consistent and … scalable API designs. • Establish API governance models, including versioning, security, documentation, and usage guidelines. • Ensure compliance with relevant standards (e.g., REST, GraphQL, OpenAPI, OAuth2). • Stakeholder & Partner Collaboration • Collaborate with internal business units, external partners, and clients to understand integration needs. • Act as the point of contact for strategic API integrations with partners and third-party platforms. More ❯

Senior API/PHP Developer – Fully Remote (UK) – £80,000+ Venchr is partnering with a fast-growing SaaS company that’s redefining financial management in the luxury and yachting sector. Their platform unites accounting, payments, FX, and project management into a single, powerful ecosystem — helping clients worldwide streamline complex operations with ease. They’re now seeking a Lead PHP … Developer with a strong focus on API architecture and backend systems to join their fully remote UK-based engineering team. In this role, you’ll take ownership of designing, developing, and optimizing APIs that power mission-critical services. You’ll collaborate closely with product, DevOps, and frontend teams to ensure the platform remains scalable, secure, and future-proof. Beyond … hands-on coding, you’ll play a key part in setting technical standards, mentoring other engineers, and driving forward the API and integration strategy that underpins the company’s growth. What You’ll Bring Proven experience leading backend/API development using PHP and Laravel Expertise in RESTful API design, versioning, authentication, and performance optimization Strong More ❯

Are you a technically minded problem-solver with a passion for learning and development? This is a brilliant opportunity for a Tech Support Developer with around three years of experience to join a fast-moving, innovative tech company working on fascinating, real-world challenges. Tech Support Developer Salary: £50k Based: London (3 days in office) In this varied and … run smoothly. You’ll work closely with the engineering team, gaining hands-on experience with Node.js and backend systems, with the chance to get involved in other areas of development as your skills grow. Key Responsibilities: Investigate, troubleshoot, and resolve production issues across front-end, back-end, and infrastructure layers Collaborate with clients, customer success, and engineering teams to … platform functionality Contribute to improving support processes, documentation, and system reliability Continuously develop your technical knowledge across a range of technologies Required Skills & Experience: 3+ years’ experience in Node.js development Proficiency in TypeScript and JavaScript Experience with React , Express , and REST API development Strong understanding of SQL and Git Excellent analytical and problem-solving skills A genuine More ❯

Are you a technically minded problem-solver with a passion for learning and development? This is a brilliant opportunity for a Tech Support Developer with around three years of experience to join a fast-moving, innovative tech company working on fascinating, real-world challenges. Tech Support Developer Salary: £50k Based: London (3 days in office) In this varied and … run smoothly. You’ll work closely with the engineering team, gaining hands-on experience with Node.js and backend systems, with the chance to get involved in other areas of development as your skills grow. Key Responsibilities: Investigate, troubleshoot, and resolve production issues across front-end, back-end, and infrastructure layers Collaborate with clients, customer success, and engineering teams to … platform functionality Contribute to improving support processes, documentation, and system reliability Continuously develop your technical knowledge across a range of technologies Required Skills & Experience: 3+ years’ experience in Node.js development Proficiency in TypeScript and JavaScript Experience with React , Express , and REST API development Strong understanding of SQL and Git Excellent analytical and problem-solving skills A genuine More ❯

APIs, including endpoint testing, integration testing, and security testing. Automation Testing Skills: Proficient in developing and maintaining automated test scripts to streamline the testing process. Extensive experience in automating API testing with tools like Swagger for API documentation and Postman for API development, testing, and debugging. Familiarity with scripting languages and frameworks to enhance automation capabilities. More ❯

APIs, including endpoint testing, integration testing, and security testing. Automation Testing Skills: Proficient in developing and maintaining automated test scripts to streamline the testing process. Extensive experience in automating API testing with tools like Swagger for API documentation and Postman for API development, testing, and debugging. Familiarity with scripting languages and frameworks to enhance automation capabilities. More ❯

Work with automation-generated code and make it production-ready Build robust backend services using Python APIs and data workflows Create seamless integrations with external systems Champion AI-assisted development practices across the engineering team What You'll Do: Own backend features and API integrations (Python, FastAPI, gRPC, SQL) Adapt and extend auto-generated pipelines and front-end … outputs Build connectors for APIs, files, and external systems Integrate LLM-based capabilities with robust evaluation and monitoring Champion AI-assisted development practices and tools Set up guardrails and context packs for AI-powered workflows Mentor team members on AI development best practices Help the team ship high-quality code faster using AI tools Work closely with cross … functional teams including Solution Strategists, Data Platform, and Support teams Contribute to architectural decisions and technical strategy What We're Looking For: Strong Python backend/API development experience Solid SQL and data modeling capabilities A solid background within start-ups and able to work on multiple projects similtaneously Proven experience with integrations (APIs, SFTP, SharePoint, webhooks) Hands More ❯

Work with automation-generated code and make it production-ready Build robust backend services using Python APIs and data workflows Create seamless integrations with external systems Champion AI-assisted development practices across the engineering team What You'll Do: Own backend features and API integrations (Python, FastAPI, gRPC, SQL) Adapt and extend auto-generated pipelines and front-end … outputs Build connectors for APIs, files, and external systems Integrate LLM-based capabilities with robust evaluation and monitoring Champion AI-assisted development practices and tools Set up guardrails and context packs for AI-powered workflows Mentor team members on AI development best practices Help the team ship high-quality code faster using AI tools Work closely with cross … functional teams including Solution Strategists, Data Platform, and Support teams Contribute to architectural decisions and technical strategy What We're Looking For: Strong Python backend/API development experience Solid SQL and data modeling capabilities A solid background within start-ups and able to work on multiple projects similtaneously Proven experience with integrations (APIs, SFTP, SharePoint, webhooks) Hands More ❯

getting to know the client’s needs, the company’s platform features and technologies from the ground up. Experience needed as a Back End Developer: 3+ years of Node.js development Type Script/Strong JavaScript skills React REST API development SQL Git More ❯

getting to know the client’s needs, the company’s platform features and technologies from the ground up. Experience needed as a Back End Developer: 3+ years of Node.js development Type Script/Strong JavaScript skills React REST API development SQL Git More ❯

approach. Overview: We’re hiring on behalf of our client for a Product Engineer (backend C# .net core) to join their growing team. The role will focus on backend development for a platform that blends telephony, voice AI, and LLMs to create next-generation voice automation features. You’ll play a key role in building core product functionality, from … the future). Write performant SQL for PostgreSQL databases; help design schemas and queries. Build and manage WebSocket connections for real-time features. Build clean automation tests (unit, functional, API). Build minimal UI components using Blazor SSR (checkboxes, graphs ..etc). Assist with deployment using Docker (containerisation) and AWS (EC2, RDS). Integrate with telephony and AI services … experience with C# (.NET Core) in Linux-based production environments. Comfortable navigating ambiguity and working with minimal supervision. Strong SQL knowledge, with experience using PostgreSQL in live systems. REST API development experience; understanding of JWT and cookie-based auth. Familiarity with Docker and AWS services, from a developer perspective. Comfortable with WebSockets. Comfortable with building lightweight frontends in More ❯

approach. Overview: We’re hiring on behalf of our client for a Product Engineer (backend C# .net core) to join their growing team. The role will focus on backend development for a platform that blends telephony, voice AI, and LLMs to create next-generation voice automation features. You’ll play a key role in building core product functionality, from … the future). Write performant SQL for PostgreSQL databases; help design schemas and queries. Build and manage WebSocket connections for real-time features. Build clean automation tests (unit, functional, API). Build minimal UI components using Blazor SSR (checkboxes, graphs ..etc). Assist with deployment using Docker (containerisation) and AWS (EC2, RDS). Integrate with telephony and AI services … experience with C# (.NET Core) in Linux-based production environments. Comfortable navigating ambiguity and working with minimal supervision. Strong SQL knowledge, with experience using PostgreSQL in live systems. REST API development experience; understanding of JWT and cookie-based auth. Familiarity with Docker and AWS services, from a developer perspective. Comfortable with WebSockets. Comfortable with building lightweight frontends in More ❯

be collaborating with he strategy team on Greenfield projects which you'll take ownership of and will see the business impact of. There's a focus on backend and API development although you'll also have elements of front end work with JavaScript and React.js. Location: You'll be based in plush City office on a fulltime basis … Monday to Friday. About you: You have expertise with C# .Net, ASP.Net development You have a strong knowledge of databases (SQL or Oracle) You're comfortable with JavaScript/React You have a thorough knowledge of Computer Science fundamentals such as OOP, Design Patterns, Data Structures, Algorithms You are collaborative with excellent communication and stakeholder management skills You are … you: As a Senior Software Engineer/Developer you will receive a competitive package: Salary to £150k Bonus paid every six months based on personal performance (10-25%) Professional development Pension Health Insurance Gym membership Social events, free fruit, snacks, coffee etc. Apply now to find out more about this Senior Software Engineer/Developer (C# .Net) opportunity. At More ❯

and impact. Cutting-edge stack: Build with modern tools — Python, FastAPI, TypeScript, LLMs, MLOps — on high-stakes, real-world problems What We’re Looking For 2+ years of software development experience Proven track record of building and shipping full-stack products in fast-paced, product-driven teams Hands-on experience building production AI systems with Python, PyTorch, and LLMs … OpenAI, Anthropic, etc.), integrated into real user workflows Familiarity with MLOps tools and CI/CD for both traditional and ML-driven systems Strong backend and API development skills — comfortable owning systems end-to-end, from data pipelines to user-facing interfaces Passion for building clean, usable products that solve real problems, fast Comfortable wearing multiple hats, challenging More ❯

and impact. Cutting-edge stack: Build with modern tools — Python, FastAPI, TypeScript, LLMs, MLOps — on high-stakes, real-world problems What We’re Looking For 2+ years of software development experience Proven track record of building and shipping full-stack products in fast-paced, product-driven teams Hands-on experience building production AI systems with Python, PyTorch, and LLMs … OpenAI, Anthropic, etc.), integrated into real user workflows Familiarity with MLOps tools and CI/CD for both traditional and ML-driven systems Strong backend and API development skills — comfortable owning systems end-to-end, from data pipelines to user-facing interfaces Passion for building clean, usable products that solve real problems, fast Comfortable wearing multiple hats, challenging More ❯

be collaborating with he strategy team on Greenfield projects which you'll take ownership of and will see the business impact of. There's a focus on backend and API development although you'll also have elements of front end work with JavaScript and React.js. Location: You'll be based in plush City office on a fulltime basis … Monday to Friday. About you: You have expertise with C# .Net, ASP.Net development You have a strong knowledge of databases (SQL or Oracle) You're comfortable with JavaScript/React You have a thorough knowledge of Computer Science fundamentals such as OOP, Design Patterns, Data Structures, Algorithms You are collaborative with excellent communication and stakeholder management skills You are … you: As a Backend Software Engineer/Developer you will receive a competitive package: Salary to £150k Bonus paid every six months based on personal performance (10-25%) Professional development Pension Health Insurance Gym membership Social events, free fruit, snacks, coffee etc. Apply now to find out more about this Backend Software Engineer/Developer (C# .Net) opportunity. At More ❯

web and mobile applications. Collaboration with developers, testers, and mobile engineers is key to embedding AI insights and building a unified ecosystem. You will promote best practices in AI development, governance, ethics, and integration, shaping our innovation roadmap. Additionally, you will optimize algorithms with tools like Python, TensorFlow, PyTorch, scikit-learn, and cloud services (e.g., AWS SageMaker), including data … plus tools like Pandas, NumPy, and SQL, is essential. Experience defining value-driven AI strategies and guiding teams on best practices is required, along with knowledge of software principles, API development, CI/CD, and AI in financial contexts. Strong problem-solving, code quality focus, and collaboration skills are vital. We provide a competitive package with benefits, bonuses More ❯

up new horizons, our faith in its potential unveils a new outlook where, together, humans and machines build a new future filled with knowledge, inspiration, and incredible discoveries. The development of a functional humanoid robot underpins an era of abundance and well-being where poverty will disappear, and people will be able to choose what they want to do. … low-level language (e.g., C++, C, Bash) for developing robot-side services. Strong experience with React (or similar frameworks) for creating user-friendly and scalable web applications. Expertise in API development, data handling, and creating scalable service architectures. Proficiency with CI/CD pipelines, containerization (e.g., Docker, Kubernetes), and workflow automation. Understanding of network protocols and secure data More ❯