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.

Backend engineers use Python, Django, Django-REST-framework, GraphQL (Graphene), Celery, Postgres, and AWS (Packer, Consul, Terraform). They build and maintain the AI-driven energy management platform that powers utilities and optimises renewable generation. The global engineering team is around 1,400 people.

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.

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.

Senior WordPress Developer role: build bespoke WordPress sites and apps using PHP, MySQL, ACF, WooCommerce, Gutenberg, JavaScript (ES6+), SASS/SCSS, Git, Composer, npm, Vite, CI/CD. You’ll also drive AI-assisted development (RAG, MCP, Copilot) and mentor junior developers.

SQL, MySQL, PostgreSQL, Doris Event, QuickSight, and possibly Amplitude, Mixpanel, GA4, Airbridge, Adjust, Airflow, dbt, Git or Python. You will own analytics schema, data models, and BI dashboards for ZYMIX, a Gen Z social super-app launching in the UK, bridging product analytics with data building.

You will work with JavaScript, PHP, HTML, CSS, Laravel, Bootstrap, APIs/JSON/XML, MySQL, and optionally React. As part of a fullstack team, you will design, build, and maintain frontend and backend systems for a fine bridal jewellery manufacturer’s online platform, migrating legacy systems to Laravel.

Infosys★3.8 (17k)· London

You will work with Java, Spring Boot, Hibernate, JPA, React/Angular/Vue.js, HTML5, CSS3, JavaScript, RESTful APIs, SQL/NoSQL databases, Git, and CI/CD tools on cloud platforms (AWS, Azure, GCP). As a Senior Consultant at Infosys, a global digital services and consulting firm, you'll contribute across the consulting lifecycle—defining problems, proposing solutions, and guiding development, configuration, and deployment while mentoring teams and shaping client-focused solutions. Docker and Kubernetes experience is a plus.

Cato Networks seeks a Senior Full Stack Engineer for their secured access team to design and build web security solutions and internal infrastructure platforms using Java, Go, Spring Boot, GraphQL, PostgreSQL, MySQL, MongoDB, and Redis. The role involves end-to-end development from large-scale data processing to web interfaces, working on enterprise SaaS microservices at scale across security products and infrastructure. Requires 6+ years backend development experience, SaaS microservices expertise, and familiarity with relational/non-relational databases in CI/CD environments.

Work with Golang, Kubernetes, gRPC, RESTful APIs, HashiCorp Vault, and cloud-native tooling to build AI-powered platforms. The team, part of Citi's Chief Technology Office, defines the bank's tech and engineering strategy by engineering cutting-edge products at planetary scale.

You will work with Node.js, React, JavaScript, TypeScript, REST APIs, MySQL, Git, Next.js, Express.js, and Tailwind CSS, along with AWS or GCP cloud infrastructure. Mas & Pas Limited is the employer; no specific product or project is described in this listing.

Senior Software Engineer designs and maintains backend services and APIs using Java, Python, and Node.js, working with microservices and Spring Boot. The role involves building REST, GraphQL, and SOAP APIs, using relational and NoSQL databases (MySQL, PostgreSQL, Oracle, Redis), and performing cloud-native development in AWS environments. This position supports financial systems and integrations within the leading global business aviation company, Vista.

Wise★3.5 (42)· London

Build backend

Fivetran★3.3 (8)· London

Senior Sales Engineer working with AWS, GCP, Azure, Snowflake, BigQuery, Databricks, Kubernetes, Docker, Podman, Grafana, Linux, Windows, Python, Java, and databases like Oracle, SQL Server, Postgres, MySQL, and NoSQL. The role supports Fivetran’s Commercial sales team by understanding customer data replication needs and leading proof-of-value processes for the company’s automated data pipeline and transformation solutions.

American Express★4.1 (9.7k)· London

You will work with Kotlin/JVM, Java, React, Postgres, MongoDB, Redis, Docker, Kubernetes, and GitHub Actions. The Financial Insights and Tools group builds financial analysis software for American Express customers, powered by APIs and underlying platforms for web and mobile applications.

Work with Kotlin/JVM, Java, React, APIs, Postgres, MongoDB, Redis, Docker, Kubernetes, GCP GKE, AWS ECS/EKS, Ktor, Spring, and GitHub Actions. The Financial Insights and Tools group builds customer-facing web and mobile features that aggregate and analyze financial data to enhance personal finance management.

American Express★4.1 (9.7k)· London

Work with Kotlin/JVM, Java, React, Postgres, MongoDB, Redis, Docker, Kubernetes (GCP GKE, AWS ECS/EKS), GitHub Actions, Ktor, and Spring. The Financial Insights and Tools group within Digital Banking builds financial analysis and planning applications for American Express customers on web and mobile, powered by APIs.

You will work with PHP, MySQL, JavaScript, AJAX, HTML/CSS, modern AI tools, and the in-house “Spark” framework. Nutritics builds cloud-based apps for hospitality and foodservice businesses, managing food data, menus, supply chains, and environmental impact.

State Street★3.4 (3k)· London

You will work with ReactJS, NextJS, TypeScript, NodeJS, Java, Spring Boot, Docker, and AWS to build cloud-native microservices. The role involves modernizing legacy platforms and developing enterprise-scale applications for a financial services firm. You will also mentor junior developers.

Connected Places Catapult★3.0 (2)· London

You will apply statistical analysis, machine learning, AI, and generative AI (LLMs, agentic workflows) using Python, and work with R, Java, Terraform, and C++. As a Consultant Data Scientist, you deliver digital and data solutions to accelerate innovation for public bodies and infrastructure providers in transport and the built environment. You operate within a project-based team under guidance of a Head of Applied Data Science.

Netbuilder★3.0 (1)· London

Full-stack developers use Java, Spring Boot, React, TypeScript, Oracle, MySQL, Git, Jenkins, Spinnaker, Docker, and Kubernetes to build, enhance, and support scalable web applications, APIs, and enterprise platforms for NETbuilder, a digital solutions provider.

Sony Music Entertainment★4.2 (454)· London

Lead Software Engineer for Sony Music’s PDEGO team, working with Python, JavaScript, TypeScript, React, Snowflake, MySQL, Neo4j, Kafka, OpenSearch, REST, OAuth, and AWS. You'll lead technical design and implementation of scalable distributed systems powering global B2B2C platforms for monetization, analytics, marketing, and music release.

Sony Music Entertainment★4.2 (454)· London

The Senior Software Engineer works with Python, JavaScript, TypeScript, React, and AWS, designing RESTful APIs and services with OAuth and data platforms like MySQL, Snowflake, Kafka, and OpenSearch. Within PDEGO, this team builds and evolves scalable, full-stack platforms that power Sony Music’s global business, supporting artists, songwriters, labels, and partners.

Work across the stack with React, TypeScript, and Node.js or Golang on privacy-focused systems and architecture that keep users' location data inaccessible. As part of Wheely's small core-engineering team, you'll collaborate with Product Managers, Designers, and Software Engineers to shape solutions from concept through production.