26 to 50 of 70 API Design Jobs in London

Senior Technical Lead

Hiring Organisation
Nextech
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£85,000 - £90,000 per annum
into a repeatable process. What you'll do Phase 1 (0-3 months): Lead the greenfield implementation of all core platforms. Build foundational REST API integrations and webhook-driven automations. Define the cross-platform data model - canonical field mapping, entity relationships and data quality standards across … automations in JavaScript and Python - ticket routing, billing triggers, licence lifecycle, CRM sequences, alert-to-action logic. Build and maintain Azure middleware (Logic Apps, API Management, Service Bus) as IaC via Terraform through a CI/CD pipeline. Iterate the acquisition onboarding playbook. What we're looking for * 5+ ...

Lead .NET Engineer/Architect

Hiring Organisation
Tria
Location
City of London, London, United Kingdom
Employment Type
Permanent
Salary
£80000 - £100000/annum
code quality, and conduct structured code reviews across the delivery team. Work directly with the BA to translate business requirements into sound technical design and produce low-level design documentation. Make architecture decisions, present options clearly to non-technical stakeholders, and govern integration standards across the programme. Support … roles, with strong hands-on .NET/C# delivery. Demonstrable experience leading architecture decisions on production-grade systems, not just contributing to them. REST API design and integration experience at scale, including defining and governing integration standards. Microsoft SQL Server: schema design, query optimisation, and working knowledge ...

AI Platform/ DevOps Engineer

Hiring Organisation
The Portfolio Group
Location
City of London, London, Castle Baynard, United Kingdom
Employment Type
Permanent
Salary
£70000 - £80000/annum + Benefits
secure, and cost-efficient platform infrastructure that enables AI engineering teams to ship and operate AI products reliably in production. What you'll do Design, build, and operate cloud-native AI platform infrastructure across AWS (Lambda, API Gateway, DynamoDB, S3, CloudWatch) and Databricks Deploy and operate containerised services … workflows, and RAG components Implement observability across AI workloads using CloudWatch, MLflow, and OpenTelemetry - covering latency, throughput, cost, and system health Apply secure-by-design principles including IAM, encryption, network controls, and audit logging Work closely with AI engineers to translate prototypes and proof-of-concepts into production-ready ...

Senior Product Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
rather than hours. You ship these without needing to be guided step by step. You're not a specialist who hands off at the API boundary. You think in user outcomes and delivery units, and you're reliable: your code handles edge cases, your APIs have clean contracts … across the stack — ship workable React/TypeScript frontend for product features; not a frontend specialist, but comfortable and pragmatic Collaborate with product and design — translate ambiguous requirements into concrete shipped work; be the engineer who unblocks, not the one who waits Maintain quality at speed — handle data integrity ...

Technical Solutions Architect

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
Role You will be responsible for creating enterprise‐quality AI, ML, and Data Science based solutions. You will be involved in technology selection, API design, and establishing core patterns within our products and client projects. You will consider the functional and non‐functional requirements to inform these decisions … quality solutions, with extensive experience and familiarity with how enterprise software solutions fit into a wider technical landscape Having a solid understanding of traditional Design Patterns and the ability to adapt these to the AI world Being a strong proponent for rigorous quality processes, automated testing and IaC principles ...

Enterprise Solution Architect

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
drive revenue growth. You will be the technical lead for our Enterprise deals, working closely with the Solutions Engineering team to understand their requirements, design solutions, and oversee detailed technical validation. You will collaborate with cross-functional teams, including Sales, Product, Engineering, and Customer Success, to ensure our clients … stacks and identify technical blockers. Collaborate with account teams to prove technical feasibility and eliminate risk. Provide expert guidance on Vanta’s platform and API capabilities, best practices, and integration strategies. Design comprehensive Technical Success Plans that map Vanta’s platform to complex customer architectures. ...

Principal Technical Lead

Hiring Organisation
RSSB
Location
City of London, London, United Kingdom
Employment Type
Contract, Work From Home
delivery of the platform, ensuring the team consistently ships high-quality, production-ready increments. Ensure engineering standards are followed across the team: coding conventions, API design, security practices, and code review processes. Lead estimation, sprint planning, and decomposition of technical work; proactively identify and manage technical risk, dependencies … architecture function, clearly articulating technical constraints, risks, or emerging complexity with architectural implications, supported by evidence and proposed alternatives. Ensure application of secure-by-design principles and validate and refine Figma wireframes. Represent the team's technical work clearly and credibly to non-technical audiences. Define and enforce ...

Senior Software Engineer [Rust]

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
demands of our customers, and expand our ecosystem to open up new possibilities. Guided by our Engineering Principles , you’ll collaborate on the design, implementation, delivery and operation of our products — in short: you’ll build it, you’ll run it! In addition to working with modern development frameworks … want to continuously iterate and improve our offering without compromising the stability or long-term maintainability of our systems. We serve millions of API requests with a 99.5% availability SLA. Our platform must remain a reliable foundation that our customers can build upon as we expand (new products ...

Full Stack Software Engineer

Hiring Organisation
Brio Digital
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP 450 Daily
looking for two experienced Senior Full Stack Software Engineers to join a high-performing engineering team. You will play a senior role in the design and delivery of modern, scalable web applications, bringing strong full stack expertise across Next.js, TypeScript, and AWS in a programme delivering meaningful impact across … services nationwide. KEY RESPONSIBILITIES Design and build high-quality, scalable full stack applications using Next.js and TypeScript Develop and maintain cloud-native solutions on AWS, following well-architected and security best practices Design, build, and consume RESTful APIs, ensuring performance, reliability, and security standards are met Write ...

Full Stack Software Engineer

Hiring Organisation
Brio Digital
Location
London, Baker Street, United Kingdom
Employment Type
Contract
Contract Rate
£450/day
looking for two experienced Senior Full Stack Software Engineers to join a high-performing engineering team. You will play a senior role in the design and delivery of modern, scalable web applications, bringing strong full stack expertise across Next.js, TypeScript, and AWS in a programme delivering meaningful impact across … services nationwide. KEY RESPONSIBILITIES Design and build high-quality, scalable full stack applications using Next.js and TypeScript Develop and maintain cloud-native solutions on AWS, following well-architected and security best practices Design, build, and consume RESTful APIs, ensuring performance, reliability, and security standards are met Write ...

Director, Forward Deployed Engineering

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
lead a team of elite engineers who embed directly with Fortune 500 customers to ship deeply integrated AI agents—owning everything from agent design and evaluation to the backend services, data systems, and cloud infrastructure that make them production‐ready. You'll partner closely with our Forward Deployed … volume for senior engineering roles. Hands‐on fluency with the full AI stack. Deep familiarity with LLMs and agent systems, evaluation frameworks, backend and API design (Python or TypeScript), data systems (PostgreSQL, DynamoDB, MongoDB, or similar), and cloud infrastructure (AWS, Azure, or GCP) including Kubernetes, Docker ...

Manager - Lead AI Engineer

Hiring Organisation
Anson Mccade
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£70,000
building and knowledge-sharing initiatives Skills & Experience Required Significant senior backend development experience with strong Python proficiency (async programming, concurrency, multithreading) Expertise in RESTful API design, OpenAPI/Swagger documentation and API lifecycle best practices Hands-on experience with ML libraries: PyTorch, PySpark, scikit-learn, Hugging Face … machine learning, cloud computing or data engineering highly advantageous Professional accounting qualification desirable but not required Nice to Have Experience with Microsoft Graph API Background in audit, financial services or regulated industry technology What's on Offer A competitive salary and benefits package, flexible hybrid working across 20+ ...

Senior Full Stack Developer & AI Engineer

Hiring Organisation
Harnham - Data & Analytics Recruitment
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£440 - £540 per day
collaborative, fast-moving, and driven by technical excellence. Engineers are trusted to lead, influence, and make meaningful decisions. The Role and Deliverables Lead the design and build of end-to-end AI-powered applications, from initial architecture through to production deployment. Architect scalable backend services and intuitive frontend interfaces … that expose AI capabilities to enterprise users. Design and implement agentic AI systems, including orchestration patterns, tool integration, and evaluation approaches. Set technical direction and best practices across the full stack, ensuring high standards of quality and maintainability. Provide technical leadership through code reviews, design input, and hands ...

ERP Ecosystem Architect

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
driving alignment across various teams with different priorities, ways of working to achieve solution standardisation. You sit at the intersection of business strategy, solution design, and delivery execution, shaping how D365 integrates and evolves globally. You work closely with integration architects, solution architects, developers, engineering/product teams … event-driven patterns.* Review and approve specifications, customisations, and integrations that impact end to end process flows across multiple systems.* Facilitate cross‐system design alignment with solution owners (POS, WMS, EDI, middleware, data platform, identity/security), ensuring decisions are understood, documented, and governable.* Support environment and build strategy ...

Machine Learning Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
pipelines using Python and common ML and DL libraries (e.g. Pytorch, Tensorflow) from early conceptualisation to full deployment in scalable production environments Ability to design, deploy and maintain ML solutions on modern frameworks to meet functional business requirements, adhering to software engineering best practices and with exposure to version … control, testing, MLOps, CI/CD and API design Hands on experience in using one of 3 major cloud technologies (AWS, Azure or GCP) in a production environment, as well as ML platforms (e.g., AWS Sagemaker, Azure Machine Learning studio) Be a ‘lifelong learner’ and can demonstrate ...

Lead Engineer, Risk Technology

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
clean, maintainable, performant applications; promote best practices, and collaborate closely with our quantitative and product teams. What You’ll Do High-Performance JVM Engineering: Design and build high-quality, scalable and performant low/zero-GC JVM services and APIs Technical Translation & Risk Modeling: Understand risk models & decompose complex … experience in architecting highly performant, low-latency systems. Testing Methodologies: In-depth knowledge of testing methodologies, including TDD, back testing and stress testing Software Design Excellence: Well versed in Agile methodologies, DRY, Clean Code, API design and micro-services. Technical Ecosystem: Experience in a full range ...

Contract Senior Software Engineer (Java or Python)

Hiring Organisation
SoCode Limited
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP 650 - 700 Daily
generated code for correctness, security, and financial accuracy Desirable, but no essential: Experience with Apache Airflow or similar workflow schedulers REST or GraphQL API design experience Knowledge of fixed income, FX, or derivatives products and associated P&L/risk methodologies ...

Contract Senior Software Engineer (Java or Python)

Hiring Organisation
SoCode Limited
Location
London, Baker Street, United Kingdom
Employment Type
Contract
Contract Rate
£650 - £700/day
generated code for correctness, security, and financial accuracy Desirable, but no essential: Experience with Apache Airflow or similar workflow schedulers REST or GraphQL API design experience Knowledge of fixed income, FX, or derivatives products and associated P&L/risk methodologies ...

Full Stack Software Engineer

Hiring Organisation
83zero Ltd
Location
City, London, United Kingdom
Employment Type
Permanent
Salary
GBP 100,000 - 130,000 Annual
roles, with a track record of building solutions end-to-end Experience deploying applications in cloud environments, preferably Microsoft Azure Strong experience in REST API design and OpenAPI standards Extensive experience working with databases, data platforms, and analytical tools Ability to research, propose, and implement solutions with minimal ...

Full Stack Software Engineer

Hiring Organisation
83zero Ltd
Location
London, Lime Street, United Kingdom
Employment Type
Permanent
Salary
£100000 - £130000/annum
roles, with a track record of building solutions end-to-end Experience deploying applications in cloud environments, preferably Microsoft Azure Strong experience in REST API design and OpenAPI standards Extensive experience working with databases, data platforms, and analytical tools Ability to research, propose, and implement solutions with minimal ...

Pre-Sales Technical Architect for SaaS Integrations

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
client data will be sourced, validated, and integrated into Mondra, leveraging where possible our existing Import and Export APIs and identifying where custom API development may be required for fulfil Mondra’s data requirements. You will also contribute to the client contracting process, ensuring technical commitments are clearly defined … including mapping data sources, transformation logic, and validation processes. Identify the client’s BI requirements, and define data export strategies (preferably via existing Mondra API). Identify the authentication/authorisation capabilities of the client, and promote the integration with Mondra’s Identity Provider via Single Sign On. Leverage ...

Senior Full Stack Engineer (GCP, Python, JavaScript) Remote

Hiring Organisation
Exalto Consulting ltd
Location
London, United Kingdom
Employment Type
Contract, Work From Home
Contract Rate
£400 Per Day
assisted development workflows. ● Agile Experience: Proven track record working within Agile teams and participating in iterative delivery. ● Core Engineering: Proficiency in Git, REST API design, and modern CI/CD practices This is a great opportunity to work for an exciting organisation and to start ASAP. The role ...

Senior Python Engineer: AI Agents & Forecasting

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
LangChain or LangGraph (agent memory, tool calling, state management) Dagster in production (assets, sensors, partitions) or equivalent pipeline orchestration Strong backend fundamentals including API design, async programming, and database modelling You've built systems that had to work reliably at scale, not just pass a demo Experience 5+ ...

Senior iOS Engineer – SEO Product

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
growth, starting with the Wise Currency Converter app developing it into a best‐in‐class travel money companion. You’ll work closely with product, design, analytics, marketing and engineering from the earliest stages of an idea. We want someone who is comfortable shaping what we build, making technical decisions … other engineers to shape ideas, define requirements, and turn them into simple, high‐quality customer experiences Owning iOS development end‐to‐end, from technical design through implementation, release, and iteration Own the observability and reliability of the app, including incident management and working hours support Making architecture decisions ...

Principal Solutions Architect

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
working hours, patterns and locations to suit you and our business. About the Opportunity As a Principal Solutions Architect, you will specialise in the design, development and governance of integrated digital project controls environments across major capital programmes. This is not a general IT solutions architecture role. … needed. Key Responsibilities Define enterprise aligned solution architectures for programme controls platforms covering cost, schedule, risk, performance reporting and data governance. Lead evaluation, selection, design and configuration of programme controls systems such as EcoSys, Oracle Primavera P6 and Unifier, Aconex, CDEs including SharePoint and ProjectWise, and related digital delivery ...