Top Backend Developer Jobs in London

Design, build, and own backend microservices and integrations for an AI-focused cybersecurity platform. Implement event-driven processing, ingest high-volume endpoint events, model and persist domain data, expose APIs and webhooks, and support analytics, reporting, and customer-facing visibility features.

Design and build a scalable backend platform to ingest and sync millions of rows from diverse data sources, shorten customer onboarding, route data securely, enable parallel agentic tooling, and create automated validation and correctness guardrails while keeping systems simple and reliable.

Lead high-impact AI solutions, overseeing architecture and deployment. Partner with stakeholders, coach engineers, and drive project success from inception to launch.

Develop and maintain the xAI API for high-throughput inference, managing model serving infrastructure, request routing, and scaling.

Administer, monitor, and support Java applications and Genesys Cloud. Provide production troubleshooting, minor bug fixes and enhancements, and act as primary POC for Java apps. Develop/support microservices using Java and Spring Boot, perform analysis of system behavior, and apply problem-solving and diagnostics to maintain service quality.

Lead end-to-end delivery of complex backend features, mentor and upskill engineers, define engineering standards, participate in on-call rotations and incident escalation, conduct technical interviews, and drive improvements to development processes and tooling.

Design, build and maintain modular, scalable, performant backend systems across the full software lifecycle; diagnose and resolve system issues; mentor junior engineers; collaborate with product and cross-functional teams; iterate quickly to deliver customer-focused features.

Build and operate distributed backend services and genomic reasoning engines that combine whole genome bioinformatics with AI. Design scalable data models, retrieval and vector search systems, and deterministic guardrails to ensure scientifically accurate, explainable genomic AI for production use.

The Backend Engineer will implement new SDK and Indexer features, automate testing, support integration, and oversee production releases.

The role involves owning product feature development, participating in system design, and maintaining software performance in an agile setting.

Lead development and production deployment of proprietary LLM-based algorithms and high-scale evaluation pipelines. Implement advanced prompt engineering, ship evaluation frameworks, and work across the stack (Python, Postgres, TypeScript/React) to translate research into production-ready AI products.

Build and own backend platform systems around AI models: design APIs, data models and schemas, implement integrations and data pipelines, create internal libraries/tooling, and drive features end-to-end from design to production while collaborating with engineers and AI specialists.

Build and maintain scalable Python backend microservices: productionize data science prototypes, fix production issues, improve monitoring, and ensure tested, well-documented code following engineering best practices.

Design and build scalable backend services and data pipelines in Python, deploy with Docker/Kubernetes, integrate enterprise systems (ERP, APIs, SFTP, event buses), process multi‑terabyte datasets, implement CI/CD and infra-as-code, ensure observability and reliability, and collaborate with customers and ML teams to deliver production enterprise features.

The Senior Backend Engineer will develop backend features for an AI product in healthcare, focusing on systems architecture, data storage, and API integration, while ensuring code quality and scalability.

Build and own backend services and APIs in Java for a multi-tenant SaaS. Ship end-to-end product features, operate services on AWS/EKS and Kubernetes, improve reliability, scalability, CI/CD/GitOps, observability, and platform tooling that enables agentic development. Drive architecture and work directly with product and customers.

Own end-to-end features across Java backends and a TypeScript/Angular frontend for a multi-tenant SaaS platform. Design APIs, schema and queries (MySQL/ClickHouse), build performant UIs, write unit/integration/e2e tests, deploy via containers/CI-CD, and integrate LLM/agentic workflows to help users find and fix data quality issues.

Design and build distributed backend services for the cloud monetization platform, focusing on correctness, consistency, scalable microservices, distributed transactions, and reliable asynchronous workflows. Influence system architecture, own service implementations, and collaborate across teams to support billing, reservations, payments, and revenue flows.

Develop and maintain server-side components for Tempo's flagship Jira Cloud products using Kotlin/Java. Design scalable distributed systems and APIs, write unit/integration/performance tests, optimize performance and database queries, collaborate with product, design, QA and docs teams, and contribute to code reviews with a focus on security, UX, and maintainability.

Build fault-tolerant, reliable cloud backend services for a hyperscaling AI platform, including compute, storage, networking, managed Kubernetes, databases, billing, monitoring and ML services.

Build and maintain backend services and APIs powering onboarding, accounts, payments, cards, transfers, rewards, FX, KYC and risk. Design reliable, secure, observable systems for real transactions; integrate with partners, payment providers and AI services; improve operational workflows, data integrity, and incident handling while collaborating with product, frontend, mobile and AI teams.

Design, develop, test, and maintain scalable backend systems for link modeling and temporospatial networking. Improve performance and parallelism across heterogeneous compute (CPU/GPU), optimize computational pipelines, and enhance reliability of distributed infrastructure. Collaborate on technical designs, lead architecture decisions, and support production system health, analysis, and visualization.

Lead architecture and delivery across the Consumer domain, specialising in search. Drive scalable, resilient system design, influence cross-team product decisions, mentor senior engineers, and raise engineering standards and observability.

Build and maintain high-performance, fault-tolerant distributed backend services and data pipelines for large genomic and health datasets. Design storage, indexing, and async event workflows; optimize latency, throughput, and reliability. Partner with bioinformatics and product teams to validate scientific accuracy and guard AI-driven responses.

As a Senior Python Backend Engineer at VidRush, you'll build AI-driven video production systems, ship production-level ML/LLM services, and work closely with product teams while ensuring high autonomy and delivery speed.