BENJAMIN CEGLOWSKI

ceglow.skilinkedin.com/in/benceglowski

Principal Software Engineer

London, United Kingdom

Principal Full Stack Engineer with vast breadth & depth of experience building high-performance web applications. I specialise in frontend & full stack architecture, designing & building systems that scale, and enabling cross-functional teams to deliver superb products.

Passionate about the intersection of engineering excellence and design craft. Good user interfaces are invisible – they get out of the way and let people fulfil their intentions frictionlessly.

Currently focused on performance at scale, architecting for simplicity, honing developer experience & advocating accessibility.

Experience

HARMONIC SECURITY

2025 — Present

Principal Frontend Engineer (Permanent)

—Principal Product Engineer (user interface focused) at a fast-paced AI startup, responsible for delivering the core product interface end-to-end.

—Half of a tiny frontend team shipping massive features at lightning speed, using every tool at our disposal to ensure pace, quality, robustness and security.

—Weighing in on big and small decisions as a Product Engineer, and using full stack experience to help guide engineering and architecture practices across the spectrum of development disciplines.

—AI native role at a company whose entire product revolves around AI.

—Driving significant and continuous performance improvements, reducing load times and runtime overhead while maintaining a refined, responsive user experience.

—Instrumental in streamlining developer experience (DX), introducing tooling, build optimisations, and workflow improvements that accelerated development velocity across the team.

—Reduced product friction through thoughtful UI architecture, interaction design, and systematic refactoring, enabling faster feature delivery with fewer regressions.

—Established frontend standards and patterns that improved maintainability, consistency, and long-term scalability in a high-growth environment.

DELIBERATE SOFTWARE LTD

2021 — 2025

Lead Full Stack Software Engineer (Permanent)

—Designed and delivered end-to-end web solutions for clients across e-commerce and fintech.

—Principal-level technical leadership, mentoring, architecture, and strategic guidance.

—Perfect Moment — Full production and upkeep of e-commerce platform: TypeScript, Next.js, GraphQL, Clojure, Contentful, Commercetools.

—Moo — Full-stack services for checkout and back-end PIM integration: TypeScript, Next.js, AWS, Salsify, Commercetools.

—Ebury — Trading application: TypeScript, Next.js, Python, PostgreSQL, AWS; hands-on mentorship and technical direction.

CRAFTING THE INTERNET LTD

2018 — 2021

Lead Full Stack Software Engineer (Contract)

—Software engineering and technical leadership across transport, education, energy, and compliance. End-to-end architecture, mentorship, and best practices.

—Riskbase — Lead engineer for mobile risk-assessment app (TypeScript, React Native).

—Shell Agile Hub — Logistics tracking platform (TypeScript, React, GraphQL, Node.js, Azure).

—EF Education First — Scheduling platform for language tuition (TypeScript, React, MobX, Go).

—Trainline — International rail travel features (TypeScript, React, Redux, Node.js, C#).

ONEFINESTAY

2016 — 2018

Senior Full Stack Engineer (Permanent)

—Drove development of a new statically rendered React application architecture for the main platform.

—Advised product, SEO, and CRO teams; led migration from costly SaaS tools to in-house replacements.

—Full-stack: JavaScript, React, GraphQL, Node.js, Python, Django, AWS, Jest.

PHUSE.CA

2014 — 2016

Head of Software Engineering (Permanent)

—Led distributed, asynchronous engineering team delivering bespoke web consultancy.

—Oversaw project delivery and code quality across JavaScript, PHP, React, Node.js, Angular, Vue.js, MySQL.

—Implemented company-wide engineering standards and best practices; architected full-cycle applications.

THE BIO AGENCY

2012 — 2013

Senior Software Engineer · Frontend Team Lead (Permanent)

—Led front-end team developing web platform for Yell Group. Technical leadership, mentorship, training.

—JavaScript, HTML, CSS, PHP, MongoDB, Backbone, Ember (LAMP).

SHINE MARKETING

2011 — 2012

Web Software Engineer (Permanent)

—Developed end-to-end retail e-commerce websites for a London-based boutique consultancy.

—Delivered full-stack solutions using PHP, MySQL, JavaScript, HTML, CSS, and jQuery.

FREELANCE

2006 — 2011

Full Service Web Developer (Freelance)

—Delivered web design and development services for several Durban and London-based consultancies.

—Provided full-stack engineering across JavaScript, PHP, MySQL, Apache, and MongoDB, creating performant and maintainable digital solutions for clients.

Technical Skills

Languages

TypeScript

JavaScript

HTML5

CSS3

GraphQL

SQL

Frameworks

React

Next.js

Remix

Node.js

Astro

Svelte

Tools

Webpack

Vite

Figma

Git

Docker

CI/CD

Practices

Systems Design

Accessibility

Performance Optimisation

Test-Driven Development

Code Review

Mentorship

Education

Durban University of Technology

Bachelor of Technology (Distinction)

2006 — 2010

Kearsney College

Matric (IEB Higher Grade)

2005