Principal Software Engineer - Data & AI Platform (Hybrid)

Internetwork Expert; Greater London; Hybrid; GBP 140,000 - 190,000; Full time

Job summary

Simple Machines is a leading boutique technology firm seeking a Principal Software Engineer to design and deliver complex, scalable systems across backend, APIs, frontend, data pipelines, and cloud infrastructure. You’ll work with internal teams and client stakeholders, owning outcomes end-to-end in a consultative engineering environment.

You’ll join a high-performing team delivering a large-scale machine learning platform for global clients, collaborating across the full stack and embracing

Qualifications

• Strong foundation in JVM-based development (Kotlin preferred, Java welcome).
• Experience designing and implementing data-driven APIs.
• Background working on large-scale web services.
• Solid SQL experience, including schema design and performance-aware queries.
• Deep experience with automated testing (unit, integration; TDD/BDD preferred).

Responsibilities

• Design and build backend services for a highly scalable marketing platform.
• Own the design of APIs, applications, and supporting infrastructure.
• Document technical designs and requirements clearly for both internal teams and clients.
• Deliver solutions end-to-end: build, automate, deploy, operate, and support.
• Partner with clients and delivery teams to translate business requirements into robust technical solutions.
• Work within an Agile, iterative delivery model.
• Collaborate in a hybrid setup with both remote and in-person team members and stakeholders.

Skills

JVM development

Kotlin

Java

APIs design

Data-driven APIs

Large-scale web services

SQL schema design

Automated testing

React

TypeScript

Redux

Tailwind

AWS

GCP

Azure

Terraform

CloudFormation

Docker

Kubernetes

NoSQL

Git workflows

Scala

Functional programming

Tools

Docker

Kubernetes

Terraform

CloudFormation

AWS

GCP

Azure

ECS

React

TypeScript

Redux

Tailwind

Ktor

RxJava

DynamoDB

Cassandra

BigTable

Job description

Simple Machines is a leading boutique technology firm seeking a Principal Software Engineer to design and deliver complex, scalable systems across backend, APIs, frontend, data pipelines, and cloud infrastructure. You’ll work with internal teams and client stakeholders, owning outcomes end-to-end in a consultative engineering environment.

You’ll join a high-performing team delivering a large-scale machine learning platform for global clients, collaborating across the full stack and embracing