The role involves developing embedded software and software for high-speed network platforms, working with GPU-based infrastructure and interconnect technologies. The company builds next-generation networking solutions integrating hardware and photonics for high-performance computing systems.

Citi★3.9 (21k)· London

You will work with Java, Spring, Web3J/Web3JS, Solidity, Docker, and Hardhat/Foundry to build Citi’s Integrated Digital Assets Platform (CIDAP), integrating blockchain networks and digital asset infrastructure.

Citi★3.9 (21k)· London

Backend Java developer building the Citi Integrated Digital Assets Platform (CIDAP) using Java Spring, web3 libraries (Web3J/Web3JS), Solidity, and containerized DevOps tools (Git, Jenkins, Helm).

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.

Lead Tembo’s platform, reliability, and cloud infrastructure across AWS and Azure environments. You will work hands-on with Terraform, CI/CD pipelines, and infrastructure as code, maintaining systems for mortgage, savings, and operational platforms that support homeownership products. This director-level individual contributor role shapes infrastructure strategy, operational resilience, and production operations.

Lead the Integrations team connecting Yuno’s payment platform to PSPs and gateways globally. You’ll work with Java, Golang, Kotlin, SQL, microservices, event-driven architectures, APIs, and AI-assisted coding tools like Claude Code, shaping scalable, secure payment infrastructure.

You will work with Snowflake, DBT, SQL, GitHub Enterprise, market data platforms and AI-assisted tooling such as GitHub Copilot and Snowflake Cortex AI. You will design, build and optimise scalable data solutions and data models for a financial services programme transforming investment decision-making and regulatory reporting.

Build a production platform using FastAPI, React, GCP, PostgreSQL, Docker, Terraform, and Redis, developing agentic AI systems and evaluations for automated cyberattack investigations. You'll own reliability end-to-end, including CI/CD, SLOs, and incident response. This is a founding role at an AI-native Digital Forensics and Incident Response startup.

You'll develop high-assurance software using C++, Java, C#, Python, JavaScript, PowerShell, and Linux/Windows, with CI/CD and source-control tooling. The team delivers mission-critical cyber capabilities for UK national security programs, including secure-systems development, vulnerability research, and reverse engineering. No team size is stated.

Hudson River Trading★4.5 (2)· London

You will write and maintain critical trading infrastructure using C/C++ or Python on Linux, working closely with engineers who design trading algorithms in a fast-paced, real-time environment. The role is with Hudson River Trading, a firm that brings a scientific approach to trading financial products.

State Street★3.4 (3k)· London

You'll use SQL, Shell scripting, Python, Ansible, and ITIL to automate operations and improve production reliability. As a Production Support Engineer at State Street, you will manage application onboarding, troubleshoot incidents, and drive self-healing and resiliency patterns for the company's institutional investment services platforms.

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.

BNY★3.5 (5.5k)· London

You'll use Java 17/21 with Spring, Maven, Groovy, JavaScript/TypeScript (Angular), Docker, GitLab CI/CD, IntelliJ, Windsurf, Splunk, and AppDynamics to build secure backend services, batches, and APIs for a global financial services company.

This role leads cybersecurity and internal systems for AIOS, which builds the world’s first full-stack AI doctor. You will own security strategy, identity and access management, endpoint security, incident response, and compliance with frameworks like HIPAA, GDPR, SOC 2, and ISO 27001, working across the company's healthcare, technology, and pharmacy platforms.

Build and scale Nxera Pharma’s computational drug discovery platform, working with Python, AWS, Docker, Prefect, GitHub Actions, Terraform/CDK, PostgreSQL, and Linux. You'll develop backend services, cloud infrastructure, CI/CD pipelines, and workflow orchestration alongside computational chemists and ML engineers. No team size is stated.

Senior C# .NET developer role on the Data team of a global energy trading house, building data platforms for market data collection, real-time streaming, governance, and machine learning, with a focus on data consumption and publishing. Tech stack includes C#, .NET, ASP.NET, Angular, SQL Server/Oracle, Docker, Kafka, Azure Service Bus, Grafana, and Azure DevOps.

Core Java, Spring Boot, JPA, Hibernate, Apache Camel, IBM MQ, XML/XSD/XSLT, JSON, SQL, TeamCity, and Linux. You will build microservices and RESTful APIs, likely in a front-office/trading environment within the investment banking domain.

The developer will work with ServiceNow HRSD, Flow Designer, legacy workflows, business rules, client scripts, ATF, JavaScript, REST APIs, and import sets. They will design, configure, and test HR Service Delivery solutions across the employee lifecycle for Infinity Quest, collaborating with product owners and architects in agile teams.

You will work with C++, Python, Rust, React, and kdb+ to design and build high-performance, scalable software solutions for a market-leading technology business. The role involves writing production code, collaborating on code reviews, and solving complex technical challenges.

Design and maintain scalable data integrations using Azure Logic Apps, Storage Accounts, API Management, Microsoft Fabric, and Azure DevOps for CI/CD. You will lead integration pipelines that enable data movement across Bell, ensuring governance and reliability. The role also includes mentoring junior team members.

Design, develop and optimise scalable data solutions using Azure Databricks, Azure Data Factory and Scala. This role processes large-scale datasets, builds ETL pipelines and works with stakeholders within a London-based long-term data engineering programme.

Python, PyTorch, Ray, distributed systems, cloud and GPU infrastructure. You will build platforms and services supporting ML training and deployment, develop tooling for data processing and model lifecycle, and maintain distributed systems for a well-funded AI company.

Design AI-powered services using Python, LangChain, LangGraph, Pydantic, and Azure OpenAI with Azure AI Search. The role builds and optimizes LLM integration, RAG patterns, and pipelines to enhance employee experience in HR technology. No team size is stated.

Work with BigQuery, Airflow, BigTable, DynamoDB, Python, Scala, Spark, TensorFlow/PyTorch, Docker, Kubernetes, and LLMs building end-to-end ML pipelines. You'll own ML-powered features for the Recommendations Experience team, connecting 200M+ users with personalized music.

Design Java-based integration using Spring Boot, Apache Camel, IBM MQ, REST/SOAP APIs, and microservices. Build scalable enterprise integration platforms in a financial services trading environment, with CI/CD (Git, TeamCity), automated tests (JUnit/Cucumber), and 3rd-line production support.