76 to 100 of 201 API Development Jobs in London

formation and compliance. Today, forming and maintaining cross-border entities is slow, opaque, fragmented, and expensive. Our mission is to abstract away this complexity with a unified dashboard and API suite — becoming the invisible infrastructure layer that powers fintechs, SaaS platforms, DAOs, funds, law firms, and global professionals. We bring deep domain expertise to the table: our team also … experienced investors and operators, we’re combining sector knowledge with strong financial support to build the “Stripe for incorporation. Role - As Founding Tech Lead , you will: Own the architecture, development, and delivery of our MVP dashboard and APIs. Lead technical decisions (stack, architecture, integrations) with a pragmatic, execution-first approach. Work closely with the founders, sales, and operations team … team). Ensure security, compliance, and reliability from day one (data protection, KYC standards). Responsibilities Product Build: Deliver Stage 1 MVP (dashboard for incorporations) quickly, iterating with users. API Development: Architect Stage 2 incorporation API and ensure it can scale across jurisdictions. Technical Leadership: Make key build vs buy calls, establish coding standards, CI/CD More ❯

formation and compliance. Today, forming and maintaining cross-border entities is slow, opaque, fragmented, and expensive. Our mission is to abstract away this complexity with a unified dashboard and API suite — becoming the invisible infrastructure layer that powers fintechs, SaaS platforms, DAOs, funds, law firms, and global professionals. We bring deep domain expertise to the table: our team also … experienced investors and operators, we’re combining sector knowledge with strong financial support to build the “Stripe for incorporation. Role - As Founding Tech Lead , you will: Own the architecture, development, and delivery of our MVP dashboard and APIs. Lead technical decisions (stack, architecture, integrations) with a pragmatic, execution-first approach. Work closely with the founders, sales, and operations team … team). Ensure security, compliance, and reliability from day one (data protection, KYC standards). Responsibilities Product Build: Deliver Stage 1 MVP (dashboard for incorporations) quickly, iterating with users. API Development: Architect Stage 2 incorporation API and ensure it can scale across jurisdictions. Technical Leadership: Make key build vs buy calls, establish coding standards, CI/CD More ❯

culture What experience you’ll bring: 5+ years building complex backend systems Deep expertise in C#, .NET, and cloud platforms (Azure preferred) Experience with microservices, serverless architecture, and secure API development Strong DevOps mindset with CI/CD, observability, and automation skills Proficiency in SQL and NoSQL (CosmosDB a plus) Excellent communication and leadership skills If you want More ❯

culture What experience you’ll bring: 5+ years building complex backend systems Deep expertise in C#, .NET, and cloud platforms (Azure preferred) Experience with microservices, serverless architecture, and secure API development Strong DevOps mindset with CI/CD, observability, and automation skills Proficiency in SQL and NoSQL (CosmosDB a plus) Excellent communication and leadership skills If you want More ❯

culture What experience you’ll bring: 5+ years building complex backend systems Deep expertise in C#, .NET, and cloud platforms (Azure preferred) Experience with microservices, serverless architecture, and secure API development Strong DevOps mindset with CI/CD, observability, and automation skills Proficiency in SQL and NoSQL (CosmosDB a plus) Excellent communication and leadership skills If you want More ❯

culture What experience you’ll bring: 5+ years building complex backend systems Deep expertise in C#, .NET, and cloud platforms (Azure preferred) Experience with microservices, serverless architecture, and secure API development Strong DevOps mindset with CI/CD, observability, and automation skills Proficiency in SQL and NoSQL (CosmosDB a plus) Excellent communication and leadership skills If you want More ❯

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 C# .Net 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 … As a Senior C# Developer/Software Engineer 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 C# Developer/Software Engineer (C# .Net) opportunity. 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 ❯

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 ❯

of the leading SasS company with a presence in the UK and Europe? The Company A market leading SaaS company with a UK and European presence. They have a development team of 15 and are continuing to grow over the next 12 – 18 months. They’re a close knit team and work from the office in central London … and finish earlier, whatever you feel makes you most productive. Responsibilities Play apart in creating and implementing ideas from the beginning Collaborate with other teams to communicate and translate development plans and implement a clear road map and timeframes Increase productivity across the team Ensure best practices are adhered to Take ownership of end to end development of … features and fixing code Have an input in regular code reviews Pair with colleagues to share your knowledge Requirements 5+ years of commercial development experience Strong background in JavaScript Experience with Vue.js or React Knowledge of API development Experience with containerisation – Docker or Kubernetes Knowledge of system design and Architecture Understanding of AWS or other cloud based More ❯

of the leading SasS company with a presence in the UK and Europe? The Company A market leading SaaS company with a UK and European presence. They have a development team of 15 and are continuing to grow over the next 12 – 18 months. They’re a close knit team and work from the office in central London … and finish earlier, whatever you feel makes you most productive. Responsibilities Play apart in creating and implementing ideas from the beginning Collaborate with other teams to communicate and translate development plans and implement a clear road map and timeframes Increase productivity across the team Ensure best practices are adhered to Take ownership of end to end development of … features and fixing code Have an input in regular code reviews Pair with colleagues to share your knowledge Requirements 5+ years of commercial development experience Strong background in JavaScript Experience with Vue.js or React Knowledge of API development Experience with containerisation – Docker or Kubernetes Knowledge of system design and Architecture Understanding of AWS or other cloud based More ❯

of the leading SasS company with a presence in the UK and Europe? The Company A market leading SaaS company with a UK and European presence. They have a development team of 15 and are continuing to grow over the next 12 – 18 months. They’re a close knit team and work from the office in central London … and finish earlier, whatever you feel makes you most productive. Responsibilities Play apart in creating and implementing ideas from the beginning Collaborate with other teams to communicate and translate development plans and implement a clear road map and timeframes Increase productivity across the team Ensure best practices are adhered to Take ownership of end to end development of … features and fixing code Have an input in regular code reviews Pair with colleagues to share your knowledge Requirements 5+ years of commercial development experience Strong background in JavaScript Experience with Vue.js or React Knowledge of API development Experience with containerisation – Docker or Kubernetes Knowledge of system design and Architecture Understanding of AWS or other cloud based More ❯

of the leading SasS company with a presence in the UK and Europe? The Company A market leading SaaS company with a UK and European presence. They have a development team of 15 and are continuing to grow over the next 12 18 months. They re a close knit team and work from the office in central London … and finish earlier, whatever you feel makes you most productive. Responsibilities Play apart in creating and implementing ideas from the beginning Collaborate with other teams to communicate and translate development plans and implement a clear road map and timeframes Increase productivity across the team Ensure best practices are adhered to Take ownership of end to end development of … features and fixing code Have an input in regular code reviews Pair with colleagues to share your knowledge Requirements 5+ years of commercial development experience Strong background in JavaScript Experience with Vue.js or React Knowledge of API development Experience with containerisation Docker or Kubernetes Knowledge of system design and Architecture Understanding of AWS or other cloud based More ❯

BPSS to start; active SC required due to timescale of the project Team: 10 direct reports, part of a 60+ programme Experience: 4+ years Essential Skills Technical: Strong Ruby development (primary focus), Python experience desirable Experience across multiple services, particularly data services Docker, Kubernetes, Git/version control API development and integration Agile working practices and adherence … to technical standards Approach: Pride in producing high-quality, well-documented code Ownership of the full development process Collaborative working with user-centered design (UCD) teams Thrives in small, agile, multi-disciplinary teams Key Responsibilities: Develop Ruby-based applications and data services Build and maintain APIs and open data platforms Ensure code is high-quality and well-documented Work … For: Senior Ruby developer with strong focus on code quality Experience working with data services Comfortable working in small, agile teams and collaborating with UCD teams Desirable Skills: Python development Experience in public sector or government projects Knowledge of search technologies and open data platforms Active SC clearance More ❯

BPSS to start; active SC required due to timescale of the project Team: 10 direct reports, part of a 60+ programme Experience: 4+ years Essential Skills Technical: Strong Ruby development (primary focus), Python experience desirable Experience across multiple services, particularly data services Docker, Kubernetes, Git/version control API development and integration Agile working practices and adherence … to technical standards Approach: Pride in producing high-quality, well-documented code Ownership of the full development process Collaborative working with user-centered design (UCD) teams Thrives in small, agile, multi-disciplinary teams Key Responsibilities: Develop Ruby-based applications and data services Build and maintain APIs and open data platforms Ensure code is high-quality and well-documented Work … For: Senior Ruby developer with strong focus on code quality Experience working with data services Comfortable working in small, agile teams and collaborating with UCD teams Desirable Skills: Python development Experience in public sector or government projects Knowledge of search technologies and open data platforms Active SC clearance More ❯

BPSS to start; active SC required due to timsecale of the project Team: 10 direct reports, part of a 60+ programme Experience: 4+ years Essential Skills Technical: Strong Python development (primary focus), Ruby experience desirable Experience across multiple services, particularly data services Docker, Kubernetes, Git/version control API development and integration Agile working practices and adherence … to technical standards Approach: Pride in writing high-quality, well-documented code Ownership of the full development process Collaborative working with user-centered design (UCD) teams Thrives in small, agile, multi-disciplinary teams Key Responsibilities: Develop Python-based applications and data services Build and maintain APIs and open data platforms Ensure code is of high quality and well-documented More ❯

Senior Full Stack Developer - Hybrid - £650/day Outside IR35 React .NET Python AWS API Asset Management Wealth Management Looking to speak with experienced Full Stack Developers to join a client of ours within the Asset space. They're looking to build a new division within the tech team and are looking for a Senior/Lead Full … Stack Developer. Details 3 days onsite in London Up to £650/day Outside IR35 Initial 6-month contract Key Skills Strong experience in full-stack development, with React, and .NET or Python Hands-on experience with AWS Strong API development and integration experience Experience with event-driven architecture Senior Full Stack Developer - Hybrid -  …/day Outside IR35 React .NET Python AWS API Asset Management Wealth Management More ❯

will play a pivotal role in helping to shape our data strategy. The Senior Data Analyst will lead on designing and delivering data solutions while remaining hands-on with development, demonstrating effective project management capabilities and the ability to juggle multiple priorities successfully. This role requires strong expertise in developing robust data solutions and interactive dashboards using Power BI … leadership on best practices, emerging technologies, and opportunities for innovation. Lead complex data transformation initiatives from inception to delivery, ensuring alignment with business objectives and regulatory requirements. Drive the development of existing and new advanced Power BI dashboards and reports. Assume ownership of data within Microsoft Dynamics 365, including cleansing, validation, and reconciliation. Design scalable data models and implement … experience in data analytics or engineering, within the financial services sector. Advanced proficiency in Power BI and Microsoft Dynamics 365 (including marketing and sales modules). Demonstrable full-stack development skills in SQL, Turbo C and Python, with proven experience in API development and data integration. Experience designing scalable data architectures and ETL pipelines. Proven ability to More ❯

will play a pivotal role in helping to shape our data strategy. The Senior Data Analyst will lead on designing and delivering data solutions while remaining hands-on with development, demonstrating effective project management capabilities and the ability to juggle multiple priorities successfully. This role requires strong expertise in developing robust data solutions and interactive dashboards using Power BI … leadership on best practices, emerging technologies, and opportunities for innovation. Lead complex data transformation initiatives from inception to delivery, ensuring alignment with business objectives and regulatory requirements. Drive the development of existing and new advanced Power BI dashboards and reports. Assume ownership of data within Microsoft Dynamics 365, including cleansing, validation, and reconciliation. Design scalable data models and implement … experience in data analytics or engineering, within the financial services sector. Advanced proficiency in Power BI and Microsoft Dynamics 365 (including marketing and sales modules). Demonstrable full-stack development skills in SQL, Turbo C and Python, with proven experience in API development and data integration. Experience designing scalable data architectures and ETL pipelines. Proven ability to More ❯

will play a pivotal role in helping to shape our data strategy. The Senior Data Analyst will lead on designing and delivering data solutions while remaining hands-on with development, demonstrating effective project management capabilities and the ability to juggle multiple priorities successfully. This role requires strong expertise in developing robust data solutions and interactive dashboards using Power BI … leadership on best practices, emerging technologies, and opportunities for innovation. Lead complex data transformation initiatives from inception to delivery, ensuring alignment with business objectives and regulatory requirements. Drive the development of existing and new advanced Power BI dashboards and reports. Assume ownership of data within Microsoft Dynamics 365, including cleansing, validation, and reconciliation. Design scalable data models and implement … experience in data analytics or engineering, within the financial services sector. Advanced proficiency in Power BI and Microsoft Dynamics 365 (including marketing and sales modules). Demonstrable full-stack development skills in SQL, Turbo C and Python, with proven experience in API development and data integration. Experience designing scalable data architectures and ETL pipelines. Proven ability to More ❯

will play a pivotal role in helping to shape our data strategy. The Senior Data Analyst will lead on designing and delivering data solutions while remaining hands-on with development, demonstrating effective project management capabilities and the ability to juggle multiple priorities successfully. This role requires strong expertise in developing robust data solutions and interactive dashboards using Power BI … leadership on best practices, emerging technologies, and opportunities for innovation. Lead complex data transformation initiatives from inception to delivery, ensuring alignment with business objectives and regulatory requirements. Drive the development of existing and new advanced Power BI dashboards and reports. Assume ownership of data within Microsoft Dynamics 365, including cleansing, validation, and reconciliation. Design scalable data models and implement … experience in data analytics or engineering, within the financial services sector. Advanced proficiency in Power BI and Microsoft Dynamics 365 (including marketing and sales modules). Demonstrable full-stack development skills in SQL, Turbo C and Python, with proven experience in API development and data integration. Experience designing scalable data architectures and ETL pipelines. Proven ability to More ❯

of the leading SasS company with a presence in the UK and Europe? The Company A market leading SaaS company with a UK and European presence. They have a development team of 15 and are continuing to grow over the next 12 – 18 months. They’re a close knit team and work from the office in central London … and finish earlier, whatever you feel makes you most productive. Responsibilities Play apart in creating and implementing ideas from the beginning Collaborate with other teams to communicate and translate development plans and implement a clear road map and timeframes Increase productivity across the team Ensure best practices are adhered to Take ownership of end to end development of … features and fixing code Have an input in regular code reviews Pair with colleagues to share your knowledge Requirements 5+ years of commercial development experience Strong background in PHP Experience with Laravel or similar frameworks Confident in JavaScript, ideally Vue.js Knowledge of API development Experience with containerisation – Docker or Kubernetes Knowledge of system design and Architecture Understanding More ❯

of the leading SasS company with a presence in the UK and Europe? The Company A market leading SaaS company with a UK and European presence. They have a development team of 15 and are continuing to grow over the next 12 – 18 months. They’re a close knit team and work from the office in central London … and finish earlier, whatever you feel makes you most productive. Responsibilities Play apart in creating and implementing ideas from the beginning Collaborate with other teams to communicate and translate development plans and implement a clear road map and timeframes Increase productivity across the team Ensure best practices are adhered to Take ownership of end to end development of … features and fixing code Have an input in regular code reviews Pair with colleagues to share your knowledge Requirements 5+ years of commercial development experience Strong background in PHP Experience with Laravel or similar frameworks Confident in JavaScript, ideally Vue.js Knowledge of API development Experience with containerisation – Docker or Kubernetes Knowledge of system design and Architecture Understanding More ❯