Senior Full-Stack Web Engineer: Scala/React, Mobile Migration

FlexTrade; City Of London; On-site; GBP 70,000 - 110,000; Full time

Job summary

FlexTrade is seeking a Senior Web Developer to join the FlexONE team and own critical product surfaces across web and mobile apps. You’ll work end-to-end on a Scala + Play backend and a React + AG-Grid frontend, using gRPC for communication with our core product’s backend systems.

You will lead the technical direction as we build our Web app from an MVP to a comprehensive companion to the desktop application, as well as continuing the evolution of our Mobile app.

Qualifications

• Strong experience with React and modern TypeScript.
• Proven ability to own features end-to-end across web and mobile apps.
• Experience with Scala/Java is a plus but not required.

Responsibilities

• Design & Build robust features across the stack (Scala/Play backend, React/AG-Grid frontend).
• Mobile Migration from Codename One to a JS-compatible framework (likely React Native).
• Quality & Reliability: testing, observability, performance across the stack.
• Team Growth: mentor engineers, assist with hiring, onboarding, and capability development as the team scales.
• Collaboration: partner closely with the Desktop application development team to ensure feature compatibility and parity.

Skills

React

TypeScript

Web development

Full stack

API design

Communication

Tools

Jenkins

GitLab

SonarQube

IntelliJ IDEA

Job description

FlexTrade is seeking a Senior Web Developer to join the FlexONE team and own critical product surfaces across web and mobile apps. You’ll work end-to-end on a Scala + Play backend and a React + AG-Grid frontend, using gRPC for communication with our core product’s backend systems.

You will lead the technical direction as we build our Web app from an MVP to a comprehensive companion to the desktop application, as well as continuing the evolution of our Mobile app.