Citi★3.9 (21k)· London

Work with Solidity, Web3J/Web3JS/Ethers.js/Viem, Java/Spring, Node.js, and blockchains such as Ethereum, Hyperledger Besu, Canton, and Solana, using Hardhat/Foundry/Truffle for testing. Contribute to Citi's Integrated Digital Assets Platform (CIDAP) building Web3 components for tokenization, smart contracts, and on-chain settlement.

You will use TensorFlow or PyTorch, Python, and CV/graphics libraries, plus 3D engines like Unreal or Unity, to develop generative models for graphics and video. As part of the Visual Computing Group, you'll design neural networks and ML for PlayStation's game rendering and live

Lovable★4.0 (43)· London

Uses Go, Rust, TypeScript; AWS, Azure, Google Cloud, Cloudflare; Kubernetes, Terraform, Temporal, OTEL, CI/CD; PostgreSQL, ClickHouse, Firestore, Spanner, BigQuery. Builds the platform for Lovable Enterprise enabling secure, cloud-agnostic deployment, defining architecture for sandboxing, networking, encryption, identity, and mentoring engineers.

Python micro-services with RabbitMQ and OpenShift/Kubernetes, using SQL Server and Parquet. The London Commodities Risk Technology team builds a front-office distributed platform for trading and risk calculations on assets like oil, gas, power, and exotics, collaborating with traders and quants.

Work with C# on .Net Framework 4.5.2+ and .Net 5+, using NUnit, xUnit, REST, Kafka/RabbitMQ, Git, and Linux. You will build Citi’s next-generation Equities technology platform for execution, clearing, and margin processes.

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.

Lovable★4.0 (43)· London

Build enterprise deployments using Go, Rust, and TypeScript on AWS, Azure, and Google Cloud, with Kubernetes, Terraform, and Temporal. You will build the platform that allows large customers to run Lovable securely and at scale across every major cloud provider.

You'll build backend runtimes, distributed systems, and orchestration services using Kubernetes, Postgres, Redis/Valkey, and object storage. Your work powers AI product runtimes that coordinate long-running agent workloads, execute code securely, and manage state across distributed environments.

Nuffield Health★3.2 (939)· London

You will work with Java 21, Spring Boot, Maven, RabbitMQ, Apache Camel, Git, GitHub Actions, Docker, Azure DevOps, Terraform, Ansible, and SQL databases. The Integration Squad designs, develops, and supports microservices and APIs for Nuffield Health's digital healthcare platforms, enabling secure connectivity across internal and third-party systems.

Atos★3.5 (3.2k)· London

You will work with **Java, Spring Boot, React JS, AWS Cloud, Microservices, Mulesoft (Anypoint Studio, API Manager), CI/CD, Git, and Jest**. The team supports, enhances, and modernizes complex enterprise applications as part of large-scale digital transformation and cloud migration programs at Atos, a global digital services provider.

A full-stack or backend specialist will use C# and .NET Framework, SQL Server (T-SQL), RESTful APIs, Azure DevOps, and messaging queues (RabbitMQ, Kafka) to build secure integration pipelines and backend services. They will execute a critical integration programme for an international Wealth Management firm to connect core internal and third-party systems.

You will work with Java, Spring Boot, React JS, JSF UI, AWS, Microservices, Mulesoft (Anypoint Studio, API Manager), CI/CD, Git and Jest. The team supports, enhances and modernizes complex enterprise applications and large-scale digital transformation initiatives for the company's global clients.

As a Backend Software Engineer, you'll use Go or Node.js to build and scale the company's core real-time messaging platform, working on low-latency Pub/Sub services and state synchronization in an AI-first engineering environment.

You will work with real-time middleware and a runtime platform for industrial control systems across AWS Data Centers. The team designs and evolves these tools to power data center infrastructure globally.

Work with Nvidia GB200 72NVL CX8 and AMD MIxxx architectures, coding in C, C++, C#, Java, JavaScript, or Python to benchmark, profile, and debug GPU clusters. You will help build foundational models powering Microsoft’s personalized AI assistant, Copilot, spanning training and inference infrastructure, model architecture, and data curation.

Python (3.10+) and Go development, with JavaScript/TypeScript for frontend; using RabbitMQ, Kafka, PostgreSQL, Redis, OpenTelemetry, and Prometheus. You will build and maintain low-latency real-time data feeds and web scraping pipelines to expand access to liquidity providers for sports prediction models.

Databricks★3.0 (21)· London

You will work with Python, Scala, JavaScript/TypeScript, Apache Spark, and cloud ecosystems (AWS, Azure, GCP) to build production-grade data and AI solutions on the Databricks platform. In this hands-on role, you lead architecture and design decisions while embedding with customer teams to deliver end-to-end data pipelines, ML/AI models, and user-facing applications.

You’ll work with Rust or Python, designing hardened sandboxed runtimes, building CLI tools, and implementing tracing/telemetry for distributed systems. Indices is building infrastructure that turns any website into a deterministic, programmable API for AI agents.

You'll work with PyTorch, distributed training, Docker/K8s/IaC, and Python backend. The company builds foundation models for extreme physics to accelerate progress in semiconductors, aerospace, defence, and fusion. Joining a small, research-heavy team, you'll be the first dedicated engineering owner for the ML stack.

G-Research★3.6 (18)· London

You will build automation frameworks and tooling using Python, Ansible, Terraform, and Jinja2, integrating them into CI/CD pipelines. This hands-on role sits at the intersection of networking and software engineering, developing APIs and self-service tools to power large-scale compute and research environments at a quantitative finance firm.

Work with Amazon Bedrock, AWS AgentCore, Python, TypeScript, and AI orchestration tools (RAG, prompt engineering, tool/function calling). Deploy and monitor production AI/ML or GenAI workloads on AWS serverless, event-driven infrastructure with CI/CD and IaC. The company builds AI agent solutions.

Design and build production-grade ML systems using MCP servers, recommendation systems, RAG pipelines, LLMs, and foundation models with Python, TensorFlow, PyTorch, FastAPI, and LangChain. You will own the end-to-end AI lifecycle for a sales data platform, deploying models into batch/real-time environments to drive forecasting, segmentation, and early warning systems. This role focuses on embedding context-aware intelligence into decision-making tools for business stakeholders.

Amazon★3.5 (56k)· London

You will architect and build a real-time middleware and runtime platform using Rust, C/C++, or Python, integrating industrial protocols like IEC 61131-3, EtherCAT, PROFINET, Modbus, OPC-UA, and IO-Link. This platform powers the industrial control systems across AWS Data Centers, connecting industrial hardware to cloud services. As the technical lead, you will own the platform’s architecture, set multi-quarter strategy, and mentor junior and mid-level SDEs.

You will own the C++17+ systems that ingest, process, and store high-rate sensor data from metal 3D printers, serving physics-informed ML inference and 3D insights in production. The work involves Python bindings (via pybind11), WebSockets, CMake, 3D geometry/meshes, and on-premise deployment. Nexus is an early-stage startup building the data and software layers for additive manufacturing of safety-critical parts.