Full-stack Java development on Linux/Unix, using AI coding tools like Claude Code, Windsurf, Devin, or GitHub Copilot. The role is for Ascendion, a technology services company.

You will build and evolve customer-facing interfaces for AI Virtual Agents using React, TypeScript, Next.js and Vite, and refactor the frontend into a scalable platform with a shared component library and design system. Unitary’s factory builds custom operations agents that complete complex workflows end-to-end in customer tools.

You will work with Python, AI coding agents (e.g., Claude Code, Codex), and potentially AWS, Kubernetes, and Temporal. Unitary builds Virtual Agents — AI-powered software workers that automate complex workflows end-to-end in customer tools, focusing on commercial insurance, marketplaces, and primary healthcare.

Goldman Sachs★3.9 (2.3k)· London

Build a high-performance, low-latency data platform for post-trade processing using Java, Kafka, Flink, SingleStore, HDFS/S3, and Scala. You will own the full lifecycle of core systems, designing distributed computation and an AI-powered UI/agent framework to deliver intelligent analytics over large-scale business data.

Zoopla★3.9 (18)· London

A 12-month maternity cover role on a dual-stack C#, .NET, and TypeScript backend with React microfrontends, using AWS managed services (ECS/Fargate, Lambda, SQS, DynamoDB, DocumentDB) and Terraform/SST. You'll build B2B SaaS software for estate agents and home builders at Alto Software Group. Take end-to-end ownership of features from design to production, working with the product team and AI coding agents.

Citi★3.9 (21k)· London

Build index‑calculation platform components at Citi using Scala and Python, integrating via REST APIs and Solace message queues, and working with Couchbase (NoSQL), Gradle, Jenkins, Tekton, and OpenShift. The SolstiCE team supports the Citi Investment Strategies (CIS) engineering group by developing and maintaining an index calculation platform for the Equity Derivatives Tech business.

DeepL★3.8 (4)· London

You'll work with C# / .NET, RESTful APIs, distributed architectures, and optionally React/TypeScript, plus MCP, CLIs, OAuth, and AI coding tools. You join the API Enterprise team, which builds enterprise adoption features (usage insights, cost controls, RBAC, compliance, data residency) for DeepL's Language AI API platform.

Native Kotlin and Jetpack Compose development on a consumer-facing Android app for in-store grocery trips, running on a known device inside live stores. Integrates on-device edge AI (ML Kit, TensorFlow Lite) and uses AI coding tools like Cursor or Claude Code. Reports to the Head of Android.

Senior Software Engineer building a multimodal AI data fusion platform for Defence and Security using Python, distributed systems, container orchestration, and agent frameworks across cloud, edge, on-premise, and air-gapped environments. You'll design core platform components, develop AI orchestration systems, define deployment architectures, and influence technical direction across the organization. Requires 7+ years shipping production software, systems design expertise, and experience architecting multimodal data systems.

Work with Java, GitHub Copilot, Devin.AI, Citi Squad, Stylus Workspaces (Gemini, OpenAI, Claude, Llama), Docker, Kubernetes, and CI/CD. Build high-performance, real-time FX risk management systems for a greenfield platform with a 10+ year strategic commitment. As a VP, lead end-to-end delivery and technical direction.

You will work with AWS, Kubernetes, Terraform, Python, Java or Scala, and AI-driven development tools (Claude, LLMs). You will build and maintain the distributed-compute and data-science platform that powers Macquarie's trading and analytics workflows, collaborating with quantitative analysts and trading desks.

Use Python, Azure, Docker, Kubernetes, Apache Airflow, and GitHub Actions to build scalable ETL pipelines, financial data pipelines, and cloud-native infrastructure. This front-office role is at a systematic equity hedge fund modernising its quantitative research platform, working directly with portfolio managers and researchers. Experience with S&P Xpressfeed, Snowflake, Bloomberg, MSCI Barra, Databricks, and LLMs is advantageous.

You will configure and maintain Workday, Greenhouse, CultureAmp, Kyriba, FloQast, and Workato, using Claude Code and agentic AI tooling. As an associate cross-platform engineer on the Finance & People Technology team, you support the SaaS estate underpinning finance and HR at a global alternative investment management firm.

Rebuild data infrastructure for a market-neutral systematic equities fund using Python, Microsoft Azure, Docker, Azure Kubernetes, Apache Airflow, and GitHub Actions for CI/CD. Work on ETL pipelines, vendor integration, and cloud-based research platforms, with relevant experience in Snowflake, Bloomberg, MSCI Barra, or Databricks. The role spans data engineering and quantitative development to transform financial data into investment signals.

Backend engineers will use Java, Elixir, Scala, and TypeScript, plus Kubernetes, Docker, Linux, git, SQL, and Spark, to build compliance technology for a tech-driven proprietary trading firm. The team supports regulatory reporting and trade surveillance across global markets, with developers owning tasks end-to-end.

You will work with Scala or Java, SQL, RDBMS, Apache Hadoop, and ANT on core backend development. The EMEA Reference Data team builds shared enterprise platforms for a global bank, supporting critical regulatory programs and international transactions.

You will use Python daily, with Ruby useful but not required, and AI tools like Claude in your workflow. The team focuses on greenfield projects in a start-up or small business environment.

Build and maintain scalable data pipelines (BigQuery, Cloud Composer, Airflow, Dataflow, Spark, Flink, dbt) on GCP for AI/ML experiences. Use Docker/k8s, Terraform, SQL, shell scripting, and monitoring tools (Monte Carlo, Looker, NewRelic, Splunk). Collaborate with product engineering, data science, and business teams.

Meta★4.0 (1.1k)· London

Work with SQL, ETL, data modeling, and languages like Python, C++, C#, or Scala to design scalable data solutions for Meta's family of apps (Facebook, Instagram, Messenger, WhatsApp, Reality Labs, Threads). Collaborate with engineering, data science, and product teams to optimize growth and user experience for billions of users and businesses.

Capital on Tap★3.9 (55)· London

First and foremost a software engineering role, you will work with C#, .NET, agentic systems and orchestration layers, and AI enablement tooling. You will build "AI on Tap", the company's internal hub for AI agents, and integrate agentic testing/verification across the pipeline to accelerate delivery for this financial platform.

You'll work across the full stack—backend distributed systems, cloud with IaC, and data pipelines including vector stores—using tools like Claude Code and AI agents for code review, refactoring, and parallel work. This Principal Engineer role on a large iGaming engagement oversees sportsbook, casino, and gaming platforms for a major client, managing a group of engineers and Tech Leads as the named delivery owner. The team includes engineers and Tech Leads that you directly line manage.

Koinly★3.0 (1)· London

Work with React 19, TypeScript, TanStack (Router, Query, Table), Radix UI, Mantine, Tailwind CSS v4, Vite, Vitest, Storybook, Highcharts, Sentry, Bun, and RabbitMQ on a data platform that reconciles crypto transactions and tax obligations for Koinly’s web application, with a React Native mobile app joining scope later.

Koinly★3.0 (1)· London

You will work with TypeScript on Bun, RabbitMQ, Redis, PostgreSQL, Vitest, Sentry, and Rust. The team owns the distributed data-processing backend that ingests, normalizes, and reconciles on-chain and exchange data for Koinly’s crypto tax calculation product.

You'll build scalable data infrastructure for AI applications using Python, SQL, Spark, dbt, LangChain, and cloud platforms (AWS, Azure, GCP), working with data pipelines, embeddings, vector search, and LLMOps tools like Terraform and LangSmith. QuantumBlack, McKinsey's AI division, develops next-generation AI systems and enterprise solutions for clients across industries. You'll collaborate with Data Scientists and ML Engineers in cross-functional Agile teams based in London, supporting the firm's AI adoption and complex problem-solving at scale.

You’ll work across full-stack engineering with AI tooling (Claude Code, agents, evals), cloud/IaC, distributed systems, APIs, data pipelines and vector stores on iGaming platforms (sportsbook, casino, gaming) for a major client. You’ll oversee a group of engineers and Tech Leads, line-managing leads and owning delivery.