Java (JDK 11+), multithreading, SQL/NoSQL databases (Oracle, MySQL, PostgreSQL, MongoDB, Cassandra), message queuing (Kafka, Tibco, Solace), Linux, JVM, and TDD. This tech lead role builds high-performance FX risk calculation systems for Citi’s Markets technology team, which supports global trading and risk management.

Palantir★3.9 (37)· London

As an intern at Palantir, you will write high-quality code for Palantir Gotham, Foundry, or Apollo using Java, Go, and TypeScript, along with open-source tools like Cassandra, Spark, Elasticsearch, React, and Redux. You will join a small product-development team building features for users in public and private sectors, such as research scientists and intelligence analysts.

Palantir★3.9 (37)· London

You’ll work with Java, C++, Python, TypeScript, JavaScript, Kubernetes, Cassandra, Chromium, and open-source tools. As a new-grad infrastructure engineer, you’ll contribute to the shared infrastructure behind Palantir Foundry, Gotham, and Apollo—platforms deployed at key public- and private-sector institutions—as well as to Rubix and Mission Manager for sensitive environments. Teams are small, focused on backend, developer, frontend, or storage infrastructure, or on production infrastructure including a Kubernetes-based PaaS, Apollo, and Signals.

Palantir★3.9 (37)· London

You'll use Java, Go, and TypeScript alongside open-source tools like Cassandra, Spark, Elasticsearch, React, and Redux with Gradle and GitHub. You'll contribute to Palantir Gotham, Apollo, or Foundry—data platforms deployed across critical institutions.

IQVIA★3.7 (2.7k)· London

Works with cloud-native architecture, data warehousing, AWS, and big data technologies including Hive, Spark, Presto, Cassandra, Hadoop, and ML

This Staff Solutions Engineer role involves using Docker, Kubernetes, NGINX, HTTP, AWS, Postgres, Cassandra, and Linux to support Kong’s API Management & Connectivity solutions. The engineer leads the technical sale cycle with Enterprise & Strategic accounts, handling demos, proof-of-concepts, and customer onboarding.

You will work with Docker, Kubernetes, NGINX, HTTP, AWS, Postgres, Cassandra, Linux, DevOps/CI/CD pipelines, and API Gateway or Service Mesh. As a Solutions Engineer, you support field sales by leading technical sale cycles for Kong’s API Management & Connectivity solutions. The company builds Kong Konnect, a unified API and AI platform for securing and managing APIs and AI models.

Apple★4.1 (14k)· London

Use Golang, C++, Java, or Python along with Kubernetes, Cassandra, Zookeeper, Kafka, Redis, and other open-source tools to build and support Apple's next-generation infrastructural platform for iCloud and backend services at hyperscale. The role includes technical leadership of projects or small teams, developing resilient API-driven services.

Sainsbury’s★3.5 (16k)· London

In this Senior Data Engineer role you will design and build scalable data pipelines and platforms using PySpark or PyTorch on AWS EMR, Snowflake, Docker, Airflow, Kubernetes, SQL/NoSQL databases and CI/CD with GitHub Actions. You will partner with Data Scientists to make data reliable and production-ready for machine learning solutions, and mentor junior and mid-level engineers.

Design, develop, and optimize data pipelines using SQL, Python, Scala, Java, or Spark, along with ETL/ELT tools like Azure Data Factory, AWS Glue, and Apache Airflow, on cloud platforms such as Azure, AWS, or GCP. You will work with databases (SQL Server, Snowflake, MongoDB), big data technologies (Spark, Kafka, Databricks), and orchestration tools to build scalable cloud-based data platforms supporting enterprise analytics and machine learning.

Design, build and optimize scalable data pipelines, ETL/ELT processes, and cloud-native data platforms using Microsoft Azure, AWS, or GCP, with tools like Apache Airflow, Azure Data Factory, or AWS Glue, and big data technologies including Apache Spark and Databricks. This London-based senior role partners with data scientists, analytics, and software engineering teams to support enterprise reporting, analytics, and machine learning initiatives.

You will work with Apache Cassandra, CQL, and Linux administration within a high-throughput fraud detection platform for a banking-sector client's Financial Crime Technology team.

Booking.com★3.7 (1.2k)· London

Work on backend services using Java, micro-services, MySQL, Hadoop, Cassandra, and possibly AWS (DynamoDB, RDS, Step functions, EC2, Kinesis). The RegTech team in Fintech builds compliance and risk-management solutions, including sanctions screening, monitoring, and regulatory reporting.

You will work with Kotlin (or Java), SQL, React, TypeScript, Redux, Tailwind, AWS/GCP/Azure, Terraform, Docker, and Kubernetes. You will design and build backend services for a large-scale marketing platform and machine learning platform for a global telecommunications client.

You'll work with Java, Akka, Cassandra, Postgres, and Kafka in an event sourcing architecture within Tesco's payment services team, which handles 100M+ daily transactions and billions of events across cash, card, gift card, and wallet payments for 28 million+ UK shoppers. The role involves building and maintaining HTTP APIs that manage payments at global scale while detecting fraud, with responsibilities including test-driven development, system design leadership, production support, and mentoring other engineers.

CrowdStrike★3.8 (54)· London

You'll work with AWS, GCP, Kubernetes, Kafka, Golang, Python

BlackRock★3.8 (632)· London

You will work with React, Angular, or Vue, Java 17+, TypeScript, RESTful and GraphQL APIs, SQL and NoSQL (Cassandra, Ignite), AWS, Azure, or GCP, Docker, Kubernetes, CI/CD, and Spring Boot. The role builds scalable web applications and high-performance APIs for BlackRock's Aladdin investment and trading platform. You will mentor junior engineers and may lead a team.

Lead a hands-on engineering team building a greenfield Agentic AI Platform for banking workflows using Python, Java/Spring Boot, and Go, with LLM/agentic frameworks (Google ADK, LangChain), GCP, Vertex AI, Elastic, Pinecone, Databricks, Kafka, Kubernetes, and Terraform. You will drive architecture, code, and mentor a new team of software and ML engineers.

Citi★3.9 (21k)· London

Lead architecture and hands-on development of a greenfield Agentic AI Platform on GCP using Vertex AI, ADK, LangChain, multi-agent architectures, and RAG with Python, Java/Spring Boot, and Kubernetes. The platform empowers Citi’s corporate and investment bankers with autonomous agents to streamline workflows and deepen client relationships.

CrowdStrike★3.8 (54)· London

You will work with Go (Golang) or C++, AWS/GCP/Azure/Kubernetes, Kafka, Cassandra, Docker, and Redis. This role is on the CrowdStrike Detection Engine platform team, which builds a next-generation platform for creating advanced, unified detections across CrowdStrike’s Falcon products, processing internet-scale data streams for real-time detection generation.

You will work with AWS, Terraform, Linux, Cassandra, Couchbase, ScyllaDB, Kafka, CI/CD pipelines, and observability platforms. The role leads the design, engineering, and operation of large-scale distributed systems and database platforms, defining technical strategy and platform roadmaps.

Wise★3.5 (42)· London

You'll use Java (Spring), Kubernetes, AWS, RESTful APIs, Swagger, OpenAPI, OAuth2, and relational/non-relational databases like MySQL, PostgreSQL, MongoDB, and Cassandra. On the Wise Platform team, you'll provide technical consulting and integration support to global financial institutions and tech companies embedding Wise's international money movement products via API.

Citi★3.9 (21k)· London

You will work with Java, Angular, microservices, event-driven architectures (Kafka, RabbitMQ), Spring Boot, Docker, Kubernetes, and AI frameworks (Python, LangChain). At Citi, a global financial services firm, you will design and deploy AI-enabled full-stack applications, integrating agentic AI to solve complex business challenges.

Morgan Stanley★3.8 (5.4k)· London

You'll work with Java, distributed caches, grid computing (Coherence, Infinispan, Hazelcast), and Scala (advantage) on a Structured Rates desk-facing squad delivering technology for traders to execute trades and manage risk, with a focus on risk management systems.

CrowdStrike★3.8 (54)· London

You'll work with Java microservices, Apache Spark/Scala, Flink, Kubernetes, and AWS tooling to build a hyper-scale data lake that processes petabytes of events daily for CrowdStrike's cybersecurity platform. Your role involves designing ultra-high-scale data platforms, writing fault-tolerant code for event pipelines and analytics, and making data accessible to internal teams and customers for threat hunting and machine learning. You'll need 10+ years backend/cloud development experience, 5+ years with Spark/Flink/Iceberg or comparable tools, and 5+ years with Java/Scala/Kotlin.