19 backend engineer jobs found in London

Senior Backend Engineer (Kotlin/GCP) 6 month contract initially, Outside IR35, Fully remote role (UK/Europe) A leading global consumer technology company is building products that prioritise safety, equity, and meaningful user experiences. They are seeking a Senior Backend Engineer with strong technical judgment, a high sense of ownership, and the ability to drive work forward even when requirements are not fully defined. You'll work primarily with Kotlin and Google Cloud Platform, helping to design, build, and evolve Back End systems that support products used by millions of users worldwide. This role suits someone who thrives in ambiguity, executes with focus, and elevates teams through clarity, momentum, and example. What You'll Do Design, build, and operate reliable, scalable Back End services using Kotlin Own and evolve systems running on GCP, contributing to architecture, reliability, observability, and cost optimisation Take loosely defined problems...

Senior Full-stack Python Typescript AI Engineer- Outside IR35   ROLE   This position is for a Senior Backend Developer working in python and typescript to support the development on a SaaS product with a focus on Ai.   This role involves designing, building, and optimising scalable backend services and APIs to support a single-tenant, multi‑instance SaaS platform, while contributing to the architecture and implementation of AI‑driven components such as Retrieval‑Augmented Generation (RAG) pipelines, vector databases, semantic search, and structured or knowledge‑graph‑based data modelling approaches. You will support the design of robust data models and pipelines capable of handling both structured and unstructured data with strong traceability and auditability, and help transition prototypes into production‑ready systems with a focus on security, access control, performance, reliability, observability, and monitoring. The role also includes building and managing...

Salesforce Engineer | £400 – £450 | Outside IR35 | 6 Months | Remote First   We’re recruiting for an experienced Salesforce Engineer for a 6-Month contract role. This position will play a key role in leading Salesforce refactoring, modernising backend systems, and driving modern engineering practices across our clients platform. Offering £400 - £450 per day, this role is determined as Outside IR35 and may require occasional travel to the office most local to you.   Key Requirements Take ownership of large‑scale Salesforce Apex refactoring and backend process improvements Enhance Salesforce integration architecture, reliability, CI/CD, and automated testing Drive modern engineering practices and support AI‑assisted development tools Resolve technical debt, improve performance, and ensure scalable architecture Requires strong Salesforce Apex, Java, CI/CD, integrations, automation, and refactoring experience Previous experience working in Fintech or regulated...

Salesforce Engineer | £400 - £450 | Outside IR35 | 6 Months | Remote First We're recruiting for an experienced Salesforce Engineer for a 6-Month contract role. This position will play a key role in leading Salesforce refactoring, modernising backend systems, and driving modern engineering practices across our clients platform. Offering £400 - £450 per day, this role is determined as Outside IR35 and may require occasional travel to the office most local to you. Key Requirements Take ownership of large-scale Salesforce Apex refactoring and backend process improvements Enhance Salesforce integration architecture, reliability, CI/CD, and automated testing Drive modern engineering practices and support AI-assisted development tools Resolve technical debt, improve performance, and ensure scalable architecture Requires strong Salesforce Apex, Java, CI/CD, integrations, automation, and refactoring experience Previous experience working in Fintech or...

Senior Full-stack Python Typescript AI Engineer- Outside IR35   ROLE   This position is for a Senior Backend Developer working in python and typescript to support the development on a SaaS product with a focus on Ai.   This role involves designing, building, and optimising scalable backend services and APIs to support a single-tenant, multi‑instance SaaS platform, while contributing to the architecture and implementation of AI‑driven components such as Retrieval‑Augmented Generation (RAG) pipelines, vector databases, semantic search, and structured or knowledge‑graph‑based data modelling approaches. You will support the design of robust data models and pipelines capable of handling both structured and unstructured data with strong traceability and auditability, and help transition prototypes into production‑ready systems with a focus on security, access control, performance, reliability, observability, and monitoring. The role also includes building and managing...

Data Engineer l AWS l Terraform l Python l DynamoDB l Backend l API l 3-Month Contract to permanent | £500- £525 per day | Remote hybrid We 're supporting a fast-growing health tech organisation looking for a hands-on Data Engineer to help stabilise and scale their AWS serverless pipelines. With rapidly increasing data volumes, they need someone who can bring automation, structure, and production-ready engineering. The Role Improve and maintain pipelines across Lambda, AppSync, DynamoDB, Postgres, SQS, ECS, and Step Functions Standardise fragmented legacy processes into scalable, automated workflows Support internal and participant-facing applications Work closely with the outgoing engineer to ensure smooth knowledge transfer Must-Have Skills Strong Terraform Deep AWS serverless experience Python for production workloads Solid DynamoDB knowledge Nice to Have GraphQL / AppSync Node.js or Python API background...

AI Engineer (Contract) – £500/day Outside IR35 📍 Canary Wharf, London (3 days onsite) 🇬🇧 UK-based applicants only We’re looking for experienced AI Engineers who think holistically, automate relentlessly, and know how to turn modern AI capabilities into production-grade, high-impact applications . Our AI organisation is building real-world AI products that deliver business value at speed. This role is ideal for seasoned engineers who combine strong software engineering fundamentals with a pragmatic, hands-on approach to AI tooling and infrastructure. What you’ll be doing Designing, building, and maintaining production-grade AI applications using modern engineering practices (CI/CD, testing, observability, cloud-native design). Developing reusable AI platforms and tools (e.g. conversational bots, AI-powered search, unstructured data processing, GenAI solutions). Working in cross-functional, embedded teams with business stakeholders to rapidly deliver...

🚀 Building a Senior AI Engineering Team (LLM + Distributed Systems) Global Investment Bank | Capital Markets Platform 📍 London (1–2 days onsite) 💰 £700–£1,200/day (Outside IR35) Contract to permanent available 📅 12-month contracts The Mandate We are building a production-grade AI platform inside a global investment bank. This is not a research team or a chatbot project. This is engineering-heavy , focused on integrating LLM systems into large-scale, distributed environments used by trading and quant teams. We are hiring across multiple levels: Lead Engineer (Agentic / RAG focus) Architect (end-to-end platform design- Agentic / RAG focus) Senior Engineers (x3) Agentic / RAG focus Potential Director-level hire to oversee the function What This Role Requires (Read Before Applying) You must have: Experience building distributed systems at scale Strong background in backend or data engineering Proven experience working on...

Contract Opportunity: AI Engineer (GenAI) Fully Remote (UK-based) Outside IR35 - £550 - £600 p/d DOE Start Date: 19th May Contract Length: 6 months (Full time) What you'll need: Strong Python engineering background (AI/ML or backend) Experience building with LLMs (LangChain, LlamaIndex, or LangGraph) Familiar with vector databases for embedding/indexing with images, audio, text and video Familiar with different multi-agent system patterns Comfortable with FastAPI or Flask Strong cloud experience (GCP or AWS) Nice to have: GCP experience Background in ML projects Experience working on data-heavy applications Familiarity with CI/CD pipelines If you're available from 19th May and interested in a short-term, high-impact GenAI project.

Java / Microservices / API design / LLMs / AI / Claude Code / Copilot Company:  Financial Services Location:  London - Hybrid 3 days per week Rate:  £575 IR35:  Outside CORE BANKING AND TRADING SYSTEMS EXPERIENCE ESSENTIAL Join a newly formed Service Modernisation & AI team driving AI-first software development in financial services. This is a hands-on role modernising high-impact legacy services while building AI-powered engineering workflows. What You’ll Do Modernise critical legacy Java services using AI-driven analysis and refactoring Apply migration patterns (e.g. strangler fig) to deliver clean, modern APIs Ship improvements in fast cycles with measurable gains in performance and reliability Build AI-powered tooling, including MCP servers and AI-assisted CI/CD pipelines Demonstrate how AI transforms developer productivity and code quality What We’re Looking For 6+ years’ backend engineering experience (Java)...

We are seeking a passionate Software Engineering Manager who will provide technical expertise and operate with excellence. Being creative, curious, and confident, you will be an integral part of our empowered, self-managing, multi-disciplinary engineering teams - designing, building, releasing, and maintaining products. You will play a key role in driving our ambition to create a best-in-class software engineering team, environment, and culture. This is an initial 6 month contract (outside IR35) that requires you to work on client site 3 days a week in London, Paddington.   Your key accountabilities will include: • Team Management: Build, mentor, and manage a high-performing software engineering team. Foster a culture of collaboration, innovation, and continuous improvement within the team. Facilitate communication and collaboration among team members. Ensure budgets, people and resource allocation, and workload, balance across projects. • Agile Delivery:...

Senior JavaScript Engineer contract - Outside IR35 - £575 per day Leading Ecommerce client is now recruiting a talented ‘Full Stack JavaScript Developer’ who is proficient in front and back-end development. (React/Node.js), with an emphasis on backend Node work initially. This role will be joining their platform team, designing, and building the foundations of which our clients innovative web and mobile applications run on. What will a day in the role entail? Working as an integral part of an agile team contributing towards the planning and development of systems/platforms. Collaborating with engineers, product owners and business analysts to define solutions, ways of working and share knowledge across the department. Reviewing code and providing support to members of your team. Working on client-facing applications in react / next.js Designing and building Node.js / GraphQL APIs. The ideal Senior JavaScript Engineer Senior level experience in modern...

Senior Software Engineer – Java (Contractor) Outside IR35 Rate: £400 - £500 per day Duration: 3 Months Plus Start Date: ASAP As a Senior Software Engineer (Java) – Contractor at Pulselive, you’ll be focused on delivering robust, high-performance backend services and APIs that power digital experiences for millions of sports fans globally. This role is ideal for an experienced, hands-on engineer with strong Java and Spring expertise who thrives in a collaborative and fast-paced delivery environment. You’ll work closely with cross-functional teams to build, integrate, and optimize systems that handle real-time sports data, video, and live commentary. This position is project- and delivery-focused, with no line management or people-leadership responsibilities required. Key Responsibilities: Design and develop scalable backend systems using Java and Spring Boot Deliver well-structured, maintainable, and testable code aligned with project...

Full job description Senior Software Engineer – Java (Contractor) Outside IR35 Rate: £400 - £500 per day Duration: 3 Months Plus Start Date: ASAP   As a  Senior Software Engineer (Java) – Contractor  at Pulselive, you’ll be focused on delivering robust, high-performance backend services and APIs that power digital experiences for millions of sports fans globally. This role is ideal for an experienced, hands-on engineer with strong Java and Spring expertise who thrives in a collaborative and fast-paced delivery environment. You’ll work closely with cross-functional teams to build, integrate, and optimize systems that handle real-time sports data, video, and live commentary. This position is project- and delivery-focused, with no line management or people-leadership responsibilities required.   Key Responsibilities: Design and develop scalable...

QA Automation Engineer Own QA at an award-winning E-commerce company E-commerce - Shopify/Recharge platform Modern QA Automation tools/frameworks (Cypress, Playwright, Selenium etc 6 months + Extensions | Outside IR35 Prior experience in E-commerce w/Shopify/Recharge heavily prioritised I'm working with an award-winning E-commerce company. Their scientifically backed, leading high street product has transformed thousands of lives and they are constantly evolving with an ever-growing customer base and successful E-commerce and subscription model. To support this evolution, they are looking for experienced QA Engineers to take over and own the QA function of the business. Ideally, you have some proficiency in test automation, modern QA tools and familiarity with key testing frameworks such as Cypress, Playwright, Selenium etc. Even more valuable if you have taken over and owned QA infrastructure/worked as a sole QA. As this is an E-commerce platform,...

Frontend Developer (Contract) - Fully Remote (UK Based) Role: Frontend Developer (Contract) Location: Fully Remote (UK) Contract Length: 6 Months (Initial) Day Rate: £400–£500 per day (Outside IR35) Start Date: ASAP 🚀 The Opportunity We’re working with a fast-growing digital product company that is scaling its engineering team to support a major platform rebuild. They are looking for a highly experienced Frontend Developer to join on a contract basis and help deliver a modern, high-performance web application used by thousands of users across the UK. This is a fully remote role (UK-based), offering the chance to work on a greenfield product with a strong engineering culture and autonomy. 🛠️ Responsibilities Build and maintain scalable frontend applications using modern frameworks Collaborate closely with designers, backend engineers, and product managers Contribute to architecture decisions and technical direction Implement responsive,...

Full job description The Role We are recruiting for a Digital Transformation Project Manager to support a government backed programme focused on modernising infrastructure and building systems. This is an outside IR35 contract offering £350 - £400 per day. Candidates must hold SC clearance or be eligible to obtain it. You will be responsible for delivering digital transformation initiatives across infrastructure, engineering and building services environments, working closely with stakeholders to ensure successful project delivery. Key Responsibilities Deliver digital transformation projects across infrastructure and building systems Manage full project lifecycle from planning through to delivery and handover Coordinate with internal teams, engineers and external stakeholders Ensure projects are delivered on time, within scope and budget Support integration of digital systems including BMS, smart building technology and asset...

QA Automation Engineer Own QA at an award-winning E-commerce company E-commerce - Shopify/Recharge platform Modern QA Automation tools/frameworks (Cypress, Playwright, Selenium etc 6 months + Extensions | Outside IR35 Prior experience in E-commerce w/Shopify/Recharge heavily prioritised I'm working with an award-winning E-commerce company. Their scientifically backed, leading high street product has transformed thousands of lives and they are constantly evolving with an ever-growing customer base and successful E-commerce and subscription model. To support this evolution, they are looking for experienced QA Engineers to take over and own the QA function of the business. Ideally, you have some proficiency in test automation, modern QA tools and familiarity with key testing frameworks such as Cypress, Playwright, Selenium etc. Even more valuable if you have taken over and owned QA infrastructure/worked as a sole QA. As this is an E-commerce platform,...

Lead DevOps Engineer (Contract) | Outside IR35 | £650/day 📍 Remote (London-based project) | 🔐 BPSS minimum | 6‑month rolling A major UK government‑backed scientific organisation is kicking off a major modernisation of its digital & engineering estate - and we’re looking for a hands‑on Lead DevOps Engineer who has led teams, owned platforms, and driven technical direction in secure, complex environments. If you’ve built high‑assurance cloud/on‑prem platforms, shaped DevOps strategy, and enjoy leading other engineers... this is the role. ✅ What You’ll Lead Driving modern DevOps practices across secure AWS/on‑prem platforms Defining IaC, CI/CD, and platform automation standards Mentoring DevOps/SRE engineers and providing technical leadership Improving reliability, observability, and delivery pipelines Working with security, research, and engineering teams on high‑impact infrastructure ✅ Tech Environment AWS • Terraform • CI/CD...