1 to 25 of 26 API Development Jobs in London

API Development - London - FTE £80k

Hiring Organisation
Uniting People
Location
London, United Kingdom
Employment Type
Any
Salary
GBP 80,000 Annual
API Development London £80k - FTE Required qualifications, capabilities, and skills Formal training or certification on API Management Platform concepts and proficient advanced experience Hands-on practical experience delivering system design, application development, testing, and operational stability Advanced in one or more programming language(s) - Golang … automation and continuous delivery methods In-depth knowledge of the financial services industry and their IT systems Practical cloud native experience Professional experience in API management technology eg APIGEE, Kong, Mulesoft Strong understand of OpenAPI Specification (OAS) for RESTful APIs DevOps (CICD, Kubernetes, Terraform) Preferred qualifications, capabilities, and skills ...

Java Developer - Java Frameworks, SC Cleared

Hiring Organisation
CBSbutler Holdings Limited trading as CBSbutler
Location
Croydon, London, United Kingdom
Employment Type
Contract
Contract Rate
£450 - £475/day
Cleared Java Developer to support the delivery of modern, cloud-based applications within an AWS environment. The role will involve backend development, API delivery, and contributing to greenfield microservices-based solutions. Hybrid working is required, with on-site presence in Croydon . Key Skills (Essential) Strong Java development experience Spring Boot SQL and report writing Experience working in AWS environments EBSA experience API development and microservices architecture Experience with CI/CD pipelines Containerisation using Docker and/or Kubernetes Experience delivering greenfield development projects Active SC Clearance Desirable Skills React Next.js Experience working ...

Solutions Architect

Hiring Organisation
Euro Car Parks
Location
Central London, London, United Kingdom
Employment Type
Permanent
though also like the idea of the equally important social/client-facing aspect of the role. The role is responsible for defining the development architecture across a blend of in-house bespoke solutions and 3rdparty products and helping to shape the longer-term strategic development architecture … developing architecture strategy and target architecture model. You will be working closely with delivery team members to coach and promote best-practice solution development architecture as well as supporting business analysts and product owners in planning and story-mapping for new development. You will act as technical design authority ...

AI Engineer

Hiring Organisation
Stackstudio Digital Ltd
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
From £450 to £475 per day
with GenAI, Gemini or Open source LLMs, Train, finetune and Onboard new LLMs Experience in building GenAI applications using Python Hands-on Experience with API Development and Microservices architecture and End to End integrations Knowledge of RAG (Retrieval-Augmented Generation) and ADK, MCP Solid understanding of LLMs, prompt … engineering, and graph-based workflows Hands-on Experience with API Development and Microservices architecture Experience in CI/CD pipelines, and containerization (Docker/Kubernetes), Harness and Git actions Practical experience implementing LLM and GenAI solutions, including prompt engineering, model fine tuning, RAG pipelines, embeddings, and vector databases ...

Dynamics 365 CRM Senior Developer

Hiring Organisation
Nigel Frank International
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£65,000 - £70,000 per annum
experienced Software Architect/Senior Developer with strong expertise in Microsoft Dynamics 365 and related technologies. The role involves leading the application development function while maintaining hands-on technical capability across the Dynamics 365 ecosystem and integrated enterprise systems. This position blends technical leadership, architectural ownership and delivery oversight … with a strong focus on system design, integration strategy and scalable solution development. Key Responsibilities Development Leadership & Delivery* Lead, mentor and support the development team.* Own and maintain the application development roadmap.* Ensure high-quality and timely delivery of development projects.* Establish coding standards, governance ...

Senior Back End Developer

Hiring Organisation
KodeLab
Location
London Area, United Kingdom
with AI and Web3 teams to power machine learning models, smart contracts, and tokenized assets . Collaborate with Front-End & DevOps Teams – Ensure seamless API integrations, CI/CD deployments, and overall system reliability. Maintain High Availability – Proactively monitor and troubleshoot issues, ensuring zero downtime for mission-critical applications. … Technical Strategy – Stay ahead of fintech trends and recommend best practices for system architecture and security. What You Bring 3+ Years of Back-End Development Experience – Strong background in high-availability, performance-driven systems. Proficiency in Node.js (or Python/Go) – Experience with backend frameworks such as Nest.js, Express.js ...

Head of Engineering

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
remains unfazed by shifting priorities. Above all, you’re a mature, intrinsically motivated technology leader who loves data. Our daily work spans building API integrations, maintaining robotic data-extraction processes, writing OCR engines, and refactoring data pipelines. At the same time, we’re beginning to invest in AI (agentic … documentation to support internal alignment and external needs (e.g. RFPs, due diligence). People & Culture : Provide career leadership: conduct regular 1:1s, support professional development, and align individual goals with Kyckr’s mission. Talent Acquisition : Recruit top engineering talent: screening, running technical and culture-fit interviews, and ensuring smooth ...

Senior Software Engineer

Hiring Organisation
Digital Waffle
Location
London Area, United Kingdom
SaaS business is hiring a Senior Back End Engineer to help build and evolve its platform, with a strong focus on modern AI-assisted development workflows. This is a hands-on role suited to someone who is already leveraging AI engineering tools day to day to improve speed, quality … across a modern TS/JS stack Working alongside legacy PHP systems, helping evolve and modernise the platform Using AI engineering tools to accelerate development, debugging and delivery Designing scalable services and clean system boundaries Integrating third-party APIs including AI, analytics and external services Collaborating closely with product ...

Full Stack NextJS Developer

Hiring Organisation
INTEC SELECT LIMITED
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£90,000 - £110,000 per annum
design build deploy) Contributing to architecture and best practices Collaborating closely with product and engineering teams What they’re looking for: 5+ years’ software development experience Strong Next.js/React/TypeScript background Experience building scalable web applications Solid understanding of SSR, SSG & frontend performance API development ...

Senior Java Backend Developer

Hiring Organisation
Vallum Associates Limited
Location
London, United Kingdom
Employment Type
Permanent
Salary
£80,000
risk management and backend operations for both corporate and retail trading. You will also contribute to shaping the technical roadmap and improving the Software Development Life Cycle (SDLC). Key Responsibilities: Design, develop, and maintain high-performance backend services for complex data processing systems Architect scalable solutions for high … years of experience in software engineering with strong Core Java expertise At least 2 years of experience working with SQL databases Strong experience in API development and automation Familiarity with cloud platforms such as AWS, Azure, or GCP Experience working in Agile environments Hands-on experience with ...

Back End Engineer

Hiring Organisation
Zuma Labs
Location
Greater London, England, United Kingdom
/finance experience. Experience with writing unit and integration tests and maintaining CI/CD pipelines. Preferred Qualifications & Experience Experience with GraphQL or REST API development. Knowledge of asynchronous programming, message queues, or real-time streaming architectures. Familiarity with cloud platforms (AWS, GCP, Azure) and container orchestration (Kubernetes/ ...

Technical Product Owner (R based)

Hiring Organisation
Stackstudio Digital Ltd
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
From £550 to £600 per day
libraries such as: tidyverse (data manipulation and visualization) data.table (high-performance data processing) caret/mlr3 (machine learning) shiny (interactive dashboards) plumber (API development) Create reusable R modules and packages for internal use Configure and manage R environments across local, server, and cloud platforms Optimize R code … privacy standards Promote coding standards, testing, and peer reviews for R scripts Evaluate and recommend new tools or libraries to enhance productivity Working with development teams to facilitate package development and deployment Configuring and managing package sources, including mirrors and custom repositories Ensuring the availability and accessibility ...

Engineering Manager - Software & ML

Hiring Organisation
Capital One UK
Location
City, London, United Kingdom
Employment Type
Permanent
Salary
GBP Annual
London, London Engineering Manager - Software & ML About this role We are looking for a Software Engineering Manager who brings a solid foundation in modern development and some experience with Machine Learning environments . You'll lead and grow a team that builds the core software powering our data-driven … Collaborate with Product Managers and Data Scientists to ensure ML models are effectively integrated into our production software. Build Robust Systems: Oversee the development of platforms that are performant, secure, and capable of handling the unique deployment needs of AI-powered features. Optimize Delivery: Enhance engineering and agile processes ...

SC Java Developer

Hiring Organisation
Sanderson Government and Defence
Location
South East London, London, United Kingdom
Employment Type
Permanent
Salary
£60,000
What You'll Work On You'll be developing robust, secure, and efficient services using modern Java frameworks and tooling. Expect to contribute to API development, containerised applications, and cross-functional engineering initiatives. Must-Have Skills Strong commercial experience with Java Hands-on expertise with RESTful APIs Proficiency ...

Software Engineer - Data Platform for Trading

Hiring Organisation
Harrington Starr
Location
City of London, London, United Kingdom
scale financial data platform, modernising legacy enterprise systems while building scalable cloud-based services on AWS. Own SQL Server optimisation, backend service design, and API development in a high-impact platform modernisation initiative. What You'll Do Develop and optimise SQL Server queries, stored procedures, and data processing … APIs Collaborate with distributed engineering and product teams Top Skills Required Advanced SQL Server expertise (performance tuning, indexing, complex queries) – non-negotiable Backend development in Python or C# AWS environment experience Proven experience in enterprise or legacy systems – critical Strong analytical and problem-solving abilities We'd expect ...

Python Developer Backend (AI) - remote

Hiring Organisation
Initialize Ltd
Location
City of London, London, United Kingdom
Employment Type
Permanent
Salary
£60,000
excellent opportunity to join this innovative and fast-growing AI tech. organisation! Skills/experience 2+ years solid commercial Python coding experience (backend, API development would be great). Good understanding of Docker, Kubernetes, and scalable distributed systems . An Agile mindset and Experience working in agile teams ...

Python Developer

Hiring Organisation
Initialize
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£40,000 - £60,000 per annum
excellent opportunity to join this innovative and fast-growing AI tech. organisation! Skills/experience 2+ years solid commercial Python coding experience (backend, API development would be great). Good understanding of Docker, and scalable distributed systems . An Agile mindset and Experience working in agile teams, using ...

Full Stack Engineer

Hiring Organisation
Stealth Startup
Location
City of London, London, United Kingdom
else's code so everything you create will also have to be thoroughly documented for future engineers as we expand the department. Key Responsibilities Development and full ownership of our core platform. Comfortable with multi-organisational architecture that you will design and build. Build intelligent document generation workflows. Implement … 3+ years commercial experience with a significant portion as a full-stack engineer. Strong experience with Node.js andReact.js — component architecture, state management, hooks, REST API development, authentication, middleware. PostgreSQL — schema design, query optimisation, migrations. Comfortable with multi-tenant SaaS architecture and making design decisions independently. Third-party API ...

Java Engineer – Buyside FX Trading Systems

Hiring Organisation
Albert Bow
Location
City of London, London, United Kingdom
work closely with a Senior Java Engineer and Lead Quant, focused on execution and delivery. Must‐Have Skills Strong Java Spring Boot REST API development Solid understanding of performance, reliability, and production systems AWS (EC2, S3) Docker/Kubernetes Terraform CI/CD pipelines Prometheus & Grafana Low‐latency ...

Full Stack Engineer - Equity

Hiring Organisation
Dental startup
Location
Central London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£60,000
right person to build it properly. The Role You'll be the first technical hire. You'll own the full stack database architecture, API layer, and front-end, and you'll work directly with the founder on every major decision. Short feedback loops, real autonomy, no committees. This … greenfield build. You won't be maintaining anyone else's code. Key Responsibilities Architect and build the core platform from scratch schema, API, and front-end Build multi-organisation, multi-location management with role-based access and isolated data per org Build intelligent auto-assignment logic and document generation ...

Data Scientist

Hiring Organisation
Stackstudio Digital Ltd
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
From £400 to £450 per day
Bias etc. Implemented security best practices, Experience to address spikes and Denial of wallet attacks, DDoS attack and other Spike arrest strategies Knowledge of API Gateways and ISTIO, ability to Diagnose and intercept failures in End to End communication Hands-on Experience with API Development and Microservices ...

Kotlin Engineer

Hiring Organisation
Ncounter
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£90,000 - £100,000 per annum
high-quality, structured information in near real time. You will join a highly capable engineering function focused on delivering scalable backend services, working across API development and Kotlin-based microservices that power content ingestion, indexing and distribution workflows. The environment is data intensive, with a strong emphasis … years commercial experience with Kotlin, or strong Java (8/11) with a desire to transition • 7+ years working across JVM-based backend development • Strong experience with Spring Boot and building RESTful or GraphQL services • Solid understanding of relational databases such as PostgreSQL or MySQL • Experience working within ...

Python Developer Backend (AI) - remote

Hiring Organisation
Initialize Ltd
Location
City, London, United Kingdom
Employment Type
Permanent
Salary
GBP 60,000 Annual
excellent opportunity to join this innovative and fast-growing AI tech. organisation! Skills/experience 2+ years solid commercial Python coding experience (backend, API development would be great). Good understanding of Docker, Kubernetes, and scalable distributed systems click apply for full job details ...

Senior Full Stack Engineer

Hiring Organisation
Access Computer Consulting
Location
City of London, London, United Kingdom
Employment Type
Contract
Contract Rate
£400 - £440/day
Java Full Stack, React, Kubernetes & Docker. Experience in building responsive, component based user interfaces using modern front end frameworks. Hands on expertise in API design and development (REST/JSON), including versioning and backward compatibility. Experience with UI testing, component testing, and front end build tooling. Experience ...

Global IT GenAI Software Engineer Director - AI & Innovation

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
/LLM engineers or data scientists developing Gen AI applications. Along with core Generative AI expertise, you will bring expertise in full backend development in technologies like python, typescript including REST, GraphQL etc. APIs development, core functional logic, performance, and stability of custom-built products. Conceptualize Generative … hallucinations, bias and other metrics in Gen AI products. Experience in constructing and querying knowledge graphs including graph‐based reasoning. Experience in front end development technologies (e.g. REACT) would be good to have. Excellent communication skills, with the ability to explain complex technical concepts to various audiences. Proven ability ...