1 to 25 of 179 API Design Jobs

Senior Software Engineer

Hiring Organisation
Tiro Partners
Location
City of London, London, United Kingdom
Employment Type
Permanent
Salary
£80000 - £120000/annum
Java/Microservices/API design/LLMs/AI/Claude Code/Copilot Role: Senior Software Engineer Company: Financial Services Location: London - Hybrid 3 days per week Salary: up to £120,000 Join a Service Modernisation team driving AI-first software development in financial services. This … development tools (e.g. Claude Code, GitHub Copilot, LLMs) Experience with MCP, AI automation, or agentic AI systems Strong understanding of microservices and API design Java/Microservices/API design/LLMs/AI/Claude Code/Copilot ...

Senior Software Engineer

Hiring Organisation
Tiro Partners Limited
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£80,000 - £120,000 per annum
Java/Microservices/API design/LLMs/AI/Claude Code/Copilot Role: Senior Software Engineer Company: Financial Services Location: London - Hybrid 3 days per week Salary: up to £120,000 Join a Service Modernisation team driving AI-first software development in financial services. This … development tools (e.g. Claude Code, GitHub Copilot, LLMs) Experience with MCP, AI automation, or agentic AI systems Strong understanding of microservices and API design Java/Microservices/API design/LLMs/AI/Claude Code/Copilot ...

Senior Software Engineer

Hiring Organisation
Logiq Systems
Location
United Kingdom
Logiq develops as we scale. You will also be the champion of software engineering best practices across Logiq Systems. A few of your responsibilities: Design and develop full-stack features using React, Python, PostgreSQL and serverless technologies (AWS Lambda, Fargate). Design and implement RESTful APIs and event … Full-stack: Proven experience in full-stack software development. We are using Python (REST & GraphQL) for the backend, React for the frontend. Cloud architecture design: Proven experience in scalable cloud architecture design. API design: Solid understanding API design (REST & GraphQL). SQL/NoSQL databases ...

Senior Web Application Developer ASP.NET MVC 5, C#, & React

Hiring Organisation
PCR Digital
Location
Hammersmith, London, United Kingdom
Employment Type
Contract
Contract Rate
£425 - £538/day Inside IR35 to Umbrella
years of Web application development experience consisting of strong C#, ASP.NET MVC 5, and React. Strong knowledge of Object-Oriented Programming, SOLID principles, common design patterns and RESTful API design and integration (experience with SOAP WebServices and XML/XPat) also required. We are looking … Server, Entity Framework, and React experience desirable to have HTML5, CSS3, JavaScript, jQuery. * Strong knowledge of Object-Oriented Programming, SOLID principles, and common design patterns. * Experienced in RESTful API design and integration; experience with SOAP WebServices and XML/XPath. * Skilled in using IoC containers (Autofac, Ninject ...

Artificial Intelligence Engineer

Hiring Organisation
SBS
Location
United Kingdom
grade AI systems in a regulated financial services environment. Location: UK or EU Hybrid/Remote: Remote (Occasional travel required) Responsibilities: AI Solution Development Design, build, and deploy AI/ML models and intelligent applications across SBS platforms Develop solutions leveraging: Machine Learning (ML) Natural Language Processing (NLP) Generative … capabilities into core banking, payments, and digital platforms Work closely with Product Managers, Architects, and Developers to embed AI into customer-facing solutions Support API development and microservices architecture for AI-driven features Data Engineering Collaboration Partner with data engineers to ensure data quality, availability, and pipeline integrity Work ...

Software Developer (UK)

Hiring Organisation
Vinley
Location
Edinburgh, Scotland, United Kingdom
APIs — Develop and extend ASP.NET Core Web APIs and Razor Pages applications (user management, admin tools, financial data services) using C# and Dapper ORM. Design and optimize SQL Server databases — Write and maintain stored procedures, manage database schema changes using SQL Server Database Projects (dacpac/sqlpackage), and optimize … queries across large financial datasets. Maintain Python data pipelines and APIs — Support and extend Python-based Flask API endpoints and data processing pipelines using pandas, ensuring data flows reliably from external sources into the platform. Work with Azure cloud services — Deploy and manage applications on Azure App Service, Azure ...

Senior Software Developer

Hiring Organisation
Birketts LLP
Location
Sevenoaks, Kent, England, United Kingdom
Employment Type
Full-Time
Salary
Competitive salary
This is a hands-on software engineering role, ideal for someone who thrives on solving complex problems in a collaborative, agile environment. You will: Design, develop and test Azure cloud native software using C# and .Net technologies, in line with an agreed schedule Ensure code is testable, safe, functional … secure, performant and reliable, all proven through testing Apply software development, microservices and API design best practices, and participate in code reviews Produce relevant and high standard documentation, developer-level tests, and deployment procedures Give accurate task estimates, and provide progress status to management Collaborate with cross-functional ...

SC Cleared Software Engineer

Hiring Organisation
TechShack
Location
United Kingdom
Employment Type
Contract
Contract Rate
GBP 450 - 500 Daily
IR35 - 6 months Rolling We're working with a government consultancy looking to hire an SC Cleared Software Engineer. The role sits between the API Design function and software delivery teams. You will be responsible for developing software that consumes API-driven data sources, contributing … definition of API standards, and supporting the rollout of those standards across existing systems. Skills: - Node.js - Angular - API Design - Active SC Clearance - Microservices experience This role is remote and has a 1 stage interview process. Role is urgent so ASAP start date. SC Cleared Software Engineer - Remote ...

Software Engineer

Hiring Organisation
TechShack
Location
United Kingdom, UK
IR35 - 6 months Rolling We're working with a government consultancy looking to hire an SC Cleared Software Engineer. The role sits between the API Design function and software delivery teams. You will be responsible for developing software that consumes API-driven data sources, contributing … definition of API standards, and supporting the rollout of those standards across existing systems. Skills: - Node.js - Angular - API Design - Active SC Clearance - Microservices experience This role is remote and has a 1 stage interview process. Role is urgent so ASAP start date. SC Cleared Software Engineer - Remote ...

Lead Full Stack Developer

Hiring Organisation
Goodman Masson
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£80,000 - £100,000 per annum
shaping Meteor's digital future. Key Responsibilities Lead, mentor, and inspire a team of developers, fostering a culture of technical excellence and continuous improvement Design, develop, and maintain high-quality software solutions across the full stack Architect and implement systems using .NET, JavaScript, SQL, and modern frontend frameworks Oversee … API design and integrations, ensuring secure and efficient data exchange Translate business and stakeholder requirements into clear technical solutions Conduct code reviews and ensure adherence to coding, security, and quality standards Drive continuous improvement in development workflows, testing, and deployment practices Support the professional development of team members ...

Product Manager – Global Card Issuing Platform (BaaS)

Hiring Organisation
WorldFirst
Location
City of London, London, United Kingdom
infrastructure that allows clients to launch card programs anywhere in the world through a single integration. You will be responsible for a unified Global API and SDK suite that abstracts the complexity of regional payment networks. Whether a client is launching in Europe, North America, or APAC, your product … will provide a consistent, white-label experience. You will drive both the technical "how" (API/SDK design) and the strategic "where" (global expansion and regional issuing setups). What you’ll do: Unified Global API Strategy: Design and maintain a single, polymorphic API architecture ...

Head of Forward Deployment Engineering

Hiring Organisation
Triple
Location
United Kingdom
agents to connect with any core banking system, card processor, or dispute platform Own the technical quality of every client integration, from secure API design and data pipeline reliability to compliance with bank-grade security requirements Create scalable deployment tooling, integration templates, and automation that reduce time … Deep experience integrating with enterprise systems in financial services, payments, or similarly regulated industries Strong proficiency in Python and SQL. Hands-on experience with API design, data pipelines, and infrastructure automation Track record of building engineering teams or functions from early stage, including hiring, process design ...

C# / .Net Software Engineer (Freelance / contractor)

Hiring Organisation
Qim info
Location
London Area, United Kingdom
collaborate with international clients and are looking for skilled contractors to support project-based engagements. 📄 Your responsibilities: The objective of this role is to design, build, and govern an API integration layer connecting multiple internal and external systems within a complex energy trading environment. 💼 Required technical skills: API … Integration Architecture: Strong expertise in API integration, REST API design and exposure, interface-driven architectures, integration-heavy environments, abstraction layers, system decoupling Backend Development: .NET Core, C#, API services, integration services Architeture & Platforms: Design of scalable and reusable integration layers, interoperability with multiple systems (internal ...

Lead Ruby Developer - Inside IR35 - Public Sector

Hiring Organisation
Tecknuovo Ltd
Location
United Kingdom
Employment Type
Contract
Contract Rate
GBP Annual
Remote Start date: ASAP Contract length: Initial contract until 30th October 2026 Project context: This project focuses on the strategic rewrite of the existing API layer between the GiT CRM and Website platform. The current architecture has created operational and maintenance challenges, and a full rewrite is required … deliver a scalable, maintainable, and long-term solution. The proposed approach will separate the API into two distinct components: A CRM-facing API responsible for interfacing directly with CRM data and services. A facade layer responsible for interfacing with wider platform services including GiT, GSE, and Apply. This ...

Principal Software Engineer (Payments)

Hiring Organisation
X4 Technology
Location
City of London, London, United Kingdom
their latest platform, provide technical expertise at both the architectural and hands-on development levels, and mentor junior team members. What You’ll Do: Design and build scalable payment applications and APIs Develop modern frontend interfaces and backend services Integrate with payment providers and financial systems Optimise database performance …/Angular), HTML5, CSS3 Backend: Python REST APIs Data: MySQL, PostgreSQL, Redis Cloud & DevOps: AWS, Docker, CI/CD, Kubernetes (nice to have) Architecture: API design, OAuth/JWT authentication, queues, webhooks, payment integrations Previous experience in Financial Services What We’re Looking For: Strong system design ...

Senior Full Stack Developer (React & C#.NET)

Hiring Organisation
Adecco
Location
London, United Kingdom
Employment Type
Contract
Python (pyspark): Experience with data pipelines and analytics is a plus. Power BI: Familiarity with developing dashboards and data models. Architecture: Knowledge of microservices, API design, and event-driven architectures. DevOps/CI/CD: Experience with Azure DevOps, GitLab, GitHub Actions, or similar tools. Cloud Platforms: Proficient … Azure preferred). Databases: Strong skills in SQL Server, PostgreSQL, or other relational databases. containerisation: Experience with Docker and Kubernetes. Key Responsibilities Design & Develop: Create and maintain full stack applications using React JS and C#.NET Core. Build Services: Develop high-performance backend services and RESTful APIs with a focus ...

Senior Java Engineer (AWS, REST, SOAP) - Hybrid - Sussex

Hiring Organisation
Salt Search
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£500 - £700 per day
engineering discipline, independent problem-solving ability, and a commitment to building robust, scalable systems. You will work across modern cloud-native architectures, contribute to API and microservices development, and help drive best practices across the engineering organisation. Key Responsibilities Design, develop, and maintain high-quality Java applications using … Spring Boot. Build and optimise RESTful APIs and contribute to GraphQL service development. Develop cloud-native solutions using AWS services such as Lambda, API Gateway, DynamoDB, ECS, S3, and others. Contribute to microservices architecture, event-driven systems, and distributed design patterns. Implement CI/CD pipelines using tools ...

Solution Architect (Principal Consultant)

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
transformation and ensuring data is protected and used ethically. Talan UK & Ireland provides a range of consultancy and outsourcing capabilities including programme management, market design and governance. We also have extensive and award-winning capabilities across cyber security, data privacy and digital transformation. We are a Great Place … recruiting an ambitious and technically accomplished Solutions Architect to join our Digital business unit as a Principal Consultant. You will lead the design and delivery of scalable, secure, and cloud-native platforms across Energy (including Low Carbon and UK regulatory systems), Financial Services, Public Sector, and Healthcare domains. This ...

Senior Developer

Hiring Organisation
Reed.co.uk
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£90,000 per annum
venture backed by the strength and stability of an established business. Key Responsibilities End-to-end development of high-quality, scalable SaaS platforms from design through deployment and maintenance. Architect and implement robust backend services primarily using Python and PostgreSQL. Develop and maintain responsive, performant front-end applications with … Provide technical mentorship and leadership to development teams, fostering best practices in coding, testing, and deployment. Participate in code reviews, architecture discussions, and system design decisions. Troubleshoot and resolve complex technical issues across the full stack. Ensure software security, scalability, and performance are maintained at all times. Keep abreast ...

Technical Co-Founder / CTO

Hiring Organisation
BLACKLINE
Location
London, England, United Kingdom
required 3. Backend Intelligence Layer * User profiles + preference memory * Provider availability + scheduling logic * Workflow orchestration (requests → bookings → confirmations) * CRM integration ⸻ Core Responsibilities * Design and build the end-to-end AI concierge system * Select and integrate LLMs, voice models, and orchestration frameworks * Build WhatsApp automation (e.g. via Twilio … architecture that scales without degrading experience ⸻ Technical Requirements You should have strong hands-on experience in: AI/LLM Systems * Prompt engineering + agent design * Tool use/function calling * Memory systems (vector DBs, session memory) * Multi-step workflow orchestration Voice Systems * Real-time speech pipelines (STT/ ...

Full Stack Java Developer

Hiring Organisation
Brio Digital
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£500/hour
looking for an experienced Senior Java Developer to join a high-performing engineering team. You will take a lead role in the design and delivery of complex, enterprise-scale solutions, bringing strong Java, AWS, and API expertise to a programme that is making a real difference to patient … care across the country. KEY RESPONSIBILITIES Lead the design and development of robust, scalable Java-based applications across the programme Build and maintain cloud-native solutions on AWS, applying well-architected principles throughout Design, develop, and test REST APIs to a high standard, ensuring performance, reliability, and security ...

AWS Solution Architect - Senior Manager

Hiring Organisation
Anson Mccade
Location
Central London, London, United Kingdom
Employment Type
Permanent
high-performing cloud practice. This is an opportunity to work at the forefront of cloud transformation, partnering with tier-one clients across industries to design and deliver innovative, scalable, and secure AWS solutions. You'll play a pivotal role in shaping enterprise cloud strategies while leading complex transformation programmes. … strategy Certifications & Education AWS Certification (Associate or Professional - e.g. Solutions Architect, DevOps Engineer) Degree in Computer Science, Engineering, or related discipline Technical Expertise Architecture & Design Translating business needs into scalable cloud architectures Cost optimisation and cloud best practices Data & AI Experience with data platforms, analytics, and AI/ ...

Senior Full Stack Engineer (AWS Microservices & Integrations)

Hiring Organisation
Narwhal Labs
Location
City Of Bristol, England, United Kingdom
SaaS product at scale. This is an office-based role and candidates must be located in or within commutable distance of Bristol. Responsibilities: Design and build microservices behind API Gateway (REST/HTTP), running on Lambda and containerised workloads on EC2/Fargate Model multi-tenant data across … DynamoDB and RDS (PostgreSQL), using S3 for object storage and KMS for secrets and encryption Build and maintain an integrations layer including OAuth/API-key onboarding, webhook ingestion with idempotency, retries and DLQs, rate-limit mediation, circuit breakers and versioned connector contracts Integrate with third-party platforms ...

Lead Architect

Hiring Organisation
Accelerant
Location
United Kingdom
pragmatic decision making Act as an escalation point for complex cross team technical challenges Ensure architectural decisions are clearly communicated, understood, and consistently applied Design and Innovation Define and maintain architectural patterns across backend services, APIs, data platforms, and front end systems Design scalable, resilient systems for analytics … data stores, favoring open standards and long term maintainability Architect distributed systems with focus on reliability, fault tolerance, and scalability Standards & Governance Establish API design standards ensuring consistency, discoverability, and ease of integration Define front end standards prioritizing web platform capabilities, progressive enhancement, and accessibility (WCAG) Create governance ...

Software Engineer - Data Platform for Trading

Hiring Organisation
Harrington Starr
Location
City of London, London, United Kingdom
large-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 logic Design and build backend services in Python or C# Modernise legacy platforms and improve system performance Build and maintain AWS-hosted services and APIs Collaborate with distributed engineering and product teams Top Skills Required Advanced SQL Server expertise (performance tuning, indexing, complex queries) – non-negotiable Backend development ...