76 to 100 of 111 API Design Jobs in London

architecture Extensive experience with PostgreSQL, including performance tuning and complex queries. Experience with background job processing using Sidekiq and Redis. Solid understanding of RESTful API design, JSON serialization, and authentication (e.g., JWT, SSO). Hands-on experience with AWS services and containerised deployments (Docker). Experience troubleshooting ...

division. This position falls under our Cross Border line of business and is located in London. In this role, you will contribute to the design and development of our eMoney and FX payment systems. You will report directly to the Engineering Manager and collaborate closely with Product, Design … will set you up for success by providing: Assigned workspace or home office setup Company-issued equipment Role Responsibilities Provide significant contribution to the design, development, and maintenance of secure and scalable payment systems. Collaborate with engineering managers, designers, and product teams to gather and analyse requirements, implement technical ...

features-you will be building impactful, user-facing applications from day one. Working closely with the founding team, you will help architect robust APIs, design intuitive frontend interfaces, and integrate cutting-edge AI/ML models into our core product. Qualifications & Experience Essential: 0-2 years of hands … projects). Education: A degree in Computer Science, Information Technology, or a related discipline. Core Fundamentals: A solid grounding in web development fundamentals, REST API design, and secure coding practices. Frontend: Proficiency in React and TypeScript, with a clear sense of how to build maintainable component hierarchies. Backend ...

role, with strong backend expertise in Typescript and Node and front capability in React • Proficiency in SQL, Redux, cloud services (AWS or GCP), RESTful API design and GraphQL • Strong analytical skills with the ability to design, optimise, and troubleshoot complex UIs • Excellent communication and leadership skills; ability ...

support and operational efficiency. This role suits a senior engineer with strong full-stack skills and a passion for modernising financial systems. Key Responsibilities Design, develop and maintain C#/.NET applications used across retail banking operations. Build modern, responsive front-end interfaces using Blazor . Work extensively with … Server to design schemas, optimise queries and improve data performance. Lead the introduction of AI and machine-learning capabilities into existing products and workflows. Collaborate with product, data and architecture teams to define AI use cases and integration patterns. Drive best practices across coding standards, testing, CI/ ...

working on the underlying systems that make complex visualisations fast, accurate, and scalable. The challenges range from rendering performance and interaction design through to algorithms, graphics, API design, and numerical correctness. What you’ll be doing Designing and building core charting features used by developers around … exceptionally high technical standards High levels of ownership and autonomy Small team, significant impact Opportunity to deepen expertise in performance, graphics, visualisation, and systems design Package Salary up to £200,000 Hybrid working (London) Private healthcare Pension Additional benefits If you’re interested in building the technology behind modern ...

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 ...

product mission by partnering with stakeholders to define strategy, technical architecture, product roadmap, and execution plans. Champion high code quality, scalable and resilient system design, and customer focus across the team. Lead by example, fostering a culture of innovation and ownership. Participate in on‐call rotation every four weeks. … teams of 6+ individual contributors, delivering major product milestones. Experience building scalable, distributed systems in public or private cloud environments. Strong knowledge of REST, API design patterns, and microservices. Experience managing full‐stack development teams (UI and backend services). Familiarity with container orchestration, deployment models, modern ...

role, with strong backend expertise in Typescript and Node and front capability in React Proficiency in SQL, Redux, cloud services (AWS or GCP), RESTful API design and GraphQL Strong analytical skills with the ability to design, optimise, and troubleshoot complex UIs Excellent communication and leadership skills; ability ...

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+ ...

evolution of core Ruby on Rails operational platforms. Optimise PostgreSQL performance and Sidekiq background job efficiency. Manage secure third-party integrations and RESTful API design. Partner with Platform teams on AWS and CI/CD reliability. The Person: Deep experience with Ruby on Rails and OOP. Expert in PostgreSQL ...

months - Hybrid - INSIDE IR35 I am working with a client who are seeking an experience Solution Architect with strong background in leading the architectural design for the replacement of legacy systems. Key Responsibilities: * 'As-Is' Architecture Baseline: Work closely with the existing technical experts to decode and document … complex, often undocumented 'As-Is' state, including direct database connections, legacy XML feeds, and custom point-to-point scripts. * Target State Design: Provide the strategic oversight for the design of the comprehensive 'To-Be' architecture mapping to the 7 core functional modules (Commissioning, Identity, Rights/Contracts, Financial ...

Data & ML Pipelines: Model data for strict auditability, versioning, and efficient querying, feeding structured datasets directly into downstream machine learning models. Empower Internal Teams: Design and implement intuitive, responsive web interfaces that allow non-technical stakeholders (Legal, Operations, Trust & Safety) to author and manage content policies with robust approval … services using Java, Kotlin, or Go . Modern Frontend Skills: Hands-on experience building clean, intuitive internal tooling using React and TypeScript . System Design & Integrity: Deep understanding of API design, backward compatibility, and data modeling for complex, versioned systems where stability is critical. Data Savvy: Experience ...

worlds leading banks in their high-performing engineering teams, building asynchronous, message-driven systems designed for scale, resilience, and near-zero downtime. Design and implement high-throughput, low-latency systems processing millions of real-time payment events Build event-driven architectures using modern Java and reactive frameworks Work extensively … with non-blocking I/O, asynchronous flows, back-pressure, and concurrency Contribute to system and API design, focusing on scalability, fault tolerance, and observability Collaborate closely with architects, engineers, and client teams across Europe Operate in Agile environments (Scrum/Kanban) with a strong engineering culture Tech ...

senior individual-contributor role within a high-performing engineering team, building asynchronous, message-driven systems designed for scale, resilience, and near-zero downtime. Design and implement high-throughput, low-latency systems processing millions of real-time payment events Build event-driven architectures using modern Java and reactive frameworks Work … extensively with non-blocking I/O, asynchronous flows, back-pressure, and concurrency Contribute to system and API design, focusing on scalability, fault tolerance, and observability Collaborate closely with architects, engineers, and client teams across Europe Operate in Agile environments (Scrum/Kanban) with a strong engineering culture ...

products (e.g., Concierge an agentic AI workflow tool, Prism a Mercer knowledge fabric for scheme data, and similar initiatives), from problem framing and design through build, release, and support. Translate risk advisory/consulting needs into clear technical requirements, user stories, and solution designs; partner with stakeholders through … Proven experience as a Tech Lead/Lead Engineer delivering production software, including hands-on coding and code review ownership. Strong backend engineering skills (API design, data modelling, performance) and experience building secure, role-based applications. Experience working directly with business stakeholders in a financial firm, with ...

improving APIs that support critical platform functionality Investigating production issues and tracing problems across distributed systems Working with product and engineering teams to design scalable solutions Improving reliability, observability and performance across existing services Reviewing code, sharing knowledge and helping raise engineering standards across the team Tackling real-world … APIs used by customers or internal teams Other Skills Needed: Solid backend engineering experience in C#, Java, or Go, with a strong grasp of API design and architecture. Hands-on experience managing and debugging production systems across cloud and self-managed infrastructure. Proven ability to navigate complex third ...

develop new features, enhance existing systems, and ensure our platform remains stable and efficient. Your deep understanding of Rails architecture, PostgreSQL optimisation, and API design will be essential as you contribute to ongoing development projects. If you enjoy collaborating in Agile/Scrum environments, value clean code ...

Senior Software Engineer — AI & Multimodal Data Platforms About the Role We are seeking an experienced Senior Software Engineer to help design and build next-generation AI systems used in Defence, Security, and Resilience environments. You will work on a cutting-edge multimodal data fusion platform that transforms large-scale … closely with senior technical leadership, platform engineers, security stakeholders, and mission-focused teams to deliver robust, scalable, production-grade software. What You’ll Do Design, build, and operate core platform components across the AI and data stack. Develop distributed systems that ingest, transform, and serve diverse multimodal datasets. Contribute ...

seasoned technical leaders. What matters is how you think, build, and ship. You'll take end-to-end ownership of features from architecture design to measurable impact - shipping code that directly moves revenue, retention, or product velocity. You'll design clean abstractions in ambiguous environments, evolve systems into … . We care about outcomes, not activity. What We're Looking For: You've built and shipped real systems. You understand data modelling, API design, system trade-offs, testing, and reliability. You know how to move fast without creating chaos. You're strong in at least one modern ...

Autogen, Google ADK). Architecting RAG pipelines, vector database integrations, and prompt management strategies. Building guardrail frameworks to prevent hallucinations, injection and bias. Designing API-first and event-driven architectures. Influencing enterprise roadmaps, governance forums and technical standards. Partnering with senior engineers, value streams, and product stakeholders. What … bring Expertise in Azure AI, AWS Bedrock or Google Vertex. Strong experience with LLM evaluation/MES frameworks. Deep knowledge of integration security, API design and cloud-native patterns. Experience delivering solutions in regulated environments (desirable). Naturally proactive, consultative and comfortable influencing at senior levels. TPBN1_UKTJ ...

across the business, embeds intelligent automation into products and workflows, and uses modern AI tools to accelerate engineering and innovation. What you'll do Design and build scalable backend services in Python (FastAPI or similar). Own cloud infrastructure across AWS (GCP experience a bonus). Build secure APIs … with product, data and client teams. What we're looking for Proven experience building and operating production backend systems at scale. Strong Python, Postgres, API design and AWS expertise. Experience with Redis, CI/CD and cloud-native architectures. A genuine AI advocate with experience using ...

TypeScript, Next.js, and Google Cloud Platform (GCP). You’ll collaborate closely with designers to create exceptional user experiences, and with platform engineers to design and implement serverless APIs and background services that scale globally. This is a fantastic opportunity to join a rapidly growing startup as we enter … equivalent commercial experience) Strong knowledge of React, TypeScript, and Next.js Experience with GCP or another cloud provider (e.g. AWS, Firebase, or Azure) Understanding of API design and asynchronous data handling Familiarity with CI/CD workflows and version control (Git) Strong problem-solving skills and attention to detail ...

ENGINEER Leading Investment House| London | Contract Role THE ROLE Design and build core AI platform components for a leading buy-side investor. You'll own the LLM gateway, MCP connector layer, observability tooling, and privacy proxy translating business use cases into governed, production-ready AI systems . WHAT … Design and maintain LLM gateway, MCP connector layer, observability, and privacy proxy Develop MCP connectors across data sources (M365, Salesforce, Kensho, Moody's, internal systems) Build AI-powered tools and workflows for business teams Integrate Databricks/Unity Catalog as data foundation for AI features Write clear specifications before ...

Data platforms - Fabric, Snowflake, CosmoDB, DataBricks, MongoDB, RDBMS Data replication/CDC - Qlik Replicate, Oracle Golden Gate Data modeling - ERStudio Message-oriented data movement API design and access Data Analytics and AL/ML - AzureML Data virtualization Streaming data Data integration and ETL/ELT Tools - Matillion, Alteryx … NoSQL data stores, methods, and approaches (star and snowflake, dimensional modelling and third normal form) Experience with data security and data access controls and design Deep understanding of SoX, GDPR and Regulatory/CNI control environments In-depth experience in providing resolution to an extensive range of complicated data ...