You will work with backend development, databases, APIs, cloud services and production machine learning systems. This is for a growing technology business. No specific project or team size is mentioned.

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.

You will work with C++, Linux, and real-time frameworks to design, develop, integrate, and verify software for high-performance real-time systems. The team builds and supports advanced test and data capture systems for the defence sector.

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

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.

Monzo★3.5 (108)· London

You will work with LLMs, autonomous agents, RAG, sequence-based architectures, Python, SQL, and Go, developing and deploying machine learning models in production. You’ll lead the design of a human-in-the-loop system that predicts, identifies, and routes customer problems to scale support for Monzo’s banking products across multiple geographies.

Monzo★3.5 (108)· London

You will build and deploy deep learning, graph-based, and sequence-based ML models using Python and SQL, with exposure to Go. You will design human-in-the-loop systems and autonomous agents to route, prioritise, and automate customer-support issues for millions of customers across thousands of support staff at Monzo. You will be one of four ML engineers embedded in product squads.

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.

Wise★3.5 (42)· London

Lead a growing Solutions Engineering team in EMEA, providing technical consulting and product guidance to top-tier banks integrating Wise’s international finance products via REST API. Work with RESTful design, OpenAPI, OAuth2, and microservice architecture to architect integrations and influence the product roadmap.

Work with Python, FastAPI, Docker, DuckDB, JSON Schema and Git to design, build and ship client ETL pipelines that map raw bank data onto the FIRE regulatory reporting standard. You will maintain a shared ETL framework, write validated mapping code, and mentor junior engineers at Suade, a regtech SaaS company automating compliance for financial institutions.

Samsara★3.6 (32)· London

Samsara interns work on the Connected Operations Cloud, building backend infrastructure in Golang, web clients with TypeScript/React and GraphQL, mobile with React Native, or embedded software for IoT devices. Projects involve scaling data ingestion, real-time data processing, and creating actionable insights for industries like transportation and agriculture.

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.

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.

Analytics Engineer role using SQL, dbt, Databricks, Kafka, Databricks Workflows, and data activation tools like Hightouch. You'll build data products and pipelines supporting ClearScore's 26 million users in making financial decisions, serving the operational platform and CRM.

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 work with time-series data, supervised and unsupervised ML, CI/CD, version control, and tools like Claude Code, MLflow, and cloud platforms (Azure, AWS, GCP) with MongoDB. Ceto provides operational intelligence for maritime, analyzing ship data to predict mechanical failures through anomaly detection and degradation forecasting.

You will work with Python, LangGraph, CrewAI, OpenAI/Claude Agent SDKs, AWS Bedrock, ECS Fargate, Lambda, Step Functions, and LLMs like GPT, Claude, and Perplexity. You will design and evolve multi-agent systems and LLM pipelines powering a production-grade AI-powered brand analytics platform that helps businesses understand market positioning.

You will build multi-agent AI systems using LangGraph, Neo4j knowledge graphs, FastAPI, and Google Cloud Platform. The role focuses on architecting and scaling AI-native software for tax advisory teams at a seed-stage London startup.

Google★4.3 (6.2k)· London

You'll develop in C++, Python, or Rust, building the Google Cloud Universal Ledger (GCUL), a cutting-edge payments platform addressing cost, speed, and fragmentation in financial systems. You'll implement low-latency features, including cryptography like homomorphic encryption and zero-knowledge proofs, while owning code for consensus, transaction dissemination, and finalisation.

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.

Hudson River Trading★4.5 (2)· London

Software engineering interns work with Python, C, or C++ on independent programming projects and gain hands-on exposure to HRT's algorithmic trading research and infrastructure.

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.