hello world

Cosmin Onea

Software Consultant / Serial Entrepreneur

Helping teams ship better software through pragmatic architecture, domain-driven design, and lean engineering practices.

About

who I am

I'm a software consultant, founder, and tech lead with over 25 years of experience building and scaling software systems. I've led engineering teams at companies like SiriusXM, Springer Nature, Pret A Manger, and Just Eat — working across payments, e-commerce, publishing, and media.

I specialise in turning complex domains into clean, maintainable architectures. Whether it's designing event-driven systems, introducing domain-driven design to a legacy codebase, or setting up lean delivery practices for a startup, I focus on solutions that work today and scale tomorrow.

As a founder, I co-founded Contingent Technologies (VC-backed) and built QontaHub, a modern accounting practice management platform. I bring the same pragmatic, product-minded approach to every engagement.

Skills & Disciplines

architecture

Domain-Driven Design Event-Driven Systems Microservices API Design

engineering

TypeScript Node.js React .NET Kotlin Go

practices

Lean Development TDD CI/CD Platform Engineering

domain

Payments E-commerce Publishing SaaS

Experience

career.map()

01

Kingfisher

Principal Software Engineer · 2026 – Present

Leading development of e-commerce platform capabilities across B&Q and Screwfix brands, focusing on scalable architecture and delivery excellence.

TypeScript React Node.js AWS Microservices
02

SiriusXM

Senior Software Engineer · 2023 – 2026

Led engineering teams building streaming platform features, driving architectural decisions and delivery practices for a global media product.

TypeScript React Node.js AWS Event-Driven
03

Springer Nature

Tech Lead / Senior Software Engineer · 2021 – 2022

Built content delivery and publishing platform systems for one of the world's largest academic publishers.

Kotlin TypeScript React AWS DDD
04

Pret A Manger

Tech Lead / Senior Software Engineer · 2021 – 2022

Developed e-commerce and digital ordering systems during a period of rapid digital transformation.

TypeScript React .NET Azure Microservices
05

Contingent Technologies

→ ventures
Co-Founder / Senior Software Engineer · 2019 – 2021

Co-founded a VC-backed startup, building the product from zero, raising funding, and bootstrapping the engineering team.

TypeScript React Node.js AWS DDD
06

Tesco

Software Engineer · 2018 – 2020

Worked on large-scale retail platform systems serving millions of customers across grocery and general merchandise.

Java Kotlin React GCP Microservices
07

Informa

Tech Lead / Senior Software Engineer · 2016 – 2018

Built content management and digital publishing platforms for a leading events and academic publishing group.

.NET TypeScript React Azure CMS
08

Just Eat

Software Engineer · 2014 – 2016

Developed core platform features for one of the UK's largest food delivery marketplaces during a period of hyper-growth.

.NET JavaScript SQL Server RabbitMQ Microservices

Ventures

founder.projects()

QontaHub

CEO / CTO

A modern Accounting Practice Management product designed to streamline workflows for accounting firms — from client onboarding to task management and compliance tracking.

  • Built from the ground up as a SaaS platform
  • Full product ownership: strategy, architecture, and engineering
  • Focused on replacing legacy tools with a modern, intuitive experience
TypeScript React Node.js PostgreSQL AWS

Contingent Technologies

Chief Product Officer / Senior Engineer

Co-founded a VC-backed startup tackling workforce management. Raised funding, bootstrapped the engineering team, and built the product from zero to market.

  • Raised venture capital funding
  • Recruited and led the founding engineering team
  • Designed and built the core platform architecture
TypeScript React Node.js AWS DDD

Contact

get in touch

Interested in working together or have a question? Drop me an email or connect on social media.