Sekimora | Conor O'Flanagan, software consultant

What I can help with

Trading and fintech front ends

Live data over WebSockets, order and position views, AML/KYC onboarding. I've worked alongside traders and compliance people and know what they ask for.

Fractional tech lead

A few days a week leading your engineers: architecture decisions, code review, release planning and mentoring. Or a one-off review of where your codebase and process stand. I led a team at Archax for four years.

I also help teams get real use out of AI coding tools like Claude Code and Codex: what to hand them, how to review what comes back, and how to fit them into your existing workflow.

Rewrites

Moving Electron or legacy apps to a single web codebase that can ship whenever you need it to. How that went at Archax.

Small products from scratch

Front end, API, Postgres, and cheap hosting on Cloudflare. Set up so someone else can take it over later.

Tools that sell for a small business

Something on your website that customers actually use: a planning check for an architect, a print file check for a print shop, a ring designer for a jeweller. It answers their question, shows what you know, and brings them back to you. See a few in progress.

Experience

Apr 2022 to 2026
London

Archax

Lead Software Developer

Led three engineers, and ran standups, retros and release planning for a group of about seven including QA, BAs and a PM.
Led the rewrite of an Electron/Finsemble desktop app into one web app for both trading and client onboarding. Front-end code went down by roughly half, and we got rid of a CMS everyone assumed we needed.
Releases used to go through several systems. Now there's one codebase and we deploy when we want.
Real-time trade management runs on plain React hooks and context, with no state library in the hot path.
Set up PostHog, which showed us for the first time where people were dropping out of onboarding (the appropriateness test and proof of address, mostly).

Nov 2018 to Oct 2021
London

J.P. Morgan

Software Engineer

Worked on the core team of a desktop trading dashboard that other teams built React widgets on. It had around 100 widgets by the time I left.
Built FDC3 context sharing, so picking a ticker in one app updated the others in the same workspace.
Helped teams replace old UIs they didn't want to maintain, and worked with traders directly on problems in their screens.
Mentored junior engineers on React.

2016 to 2018
London, Dublin

Earlier

React and React Native at When You Move, and CI/CD work at AIB.

Case studies

Replacing a desktop app · Archax

Why I told Archax to drop its desktop trading app

Archax traded through an Electron desktop app built for institutional traders, something like a Bloomberg terminal. When the company turned towards retail crypto traders, I advised replacing it, and the onboarding portal an outside team ran, with one web app. Seven months later releases were an ordinary deploy, onboarding had come in-house, and there was about half the front-end code to look after.

React, WebSockets, Cypress, PostHog

Things I run myself

Gamdromeda

A map of Steam players and the games they have in common. A crawler works through the Steam API at about one request a second, and the Postgres database is past 33 million library rows.

Node, Postgres, Docker

Marbelladex

A Next.js site with a waitlist. A Cloudflare Worker in front of it serves a cached copy from KV if the origin goes down, so visitors never get an error page.

Next.js, Cloudflare Workers and KV, SQLite

In progress

Live · for a client

How big can I build without planning permission?

Live on tof.ie for Terry & O'Flanagan, architects, and still growing. Size a rear extension in 3D and see it checked against Ireland's exempted development rules: the 45 m² limit, the 25 m² open space rule, and the 2026 changes most guides still miss.

Next.js

Proposal · for a workshop

BM WAGEN, a BMW workshop's site

For an independent BMW, MINI and Rolls-Royce workshop in San Pedro de Alcántara, whose site dates from 2014. Phone, hours and WhatsApp booking at the top, in Spanish, English and German, with their Google reviews next to the booking form.

Astro, Spanish, English and German

Concept · for a print shop

Print file check

For a print shop in San Pedro de Alcántara. Drop in a business card PDF and it checks it against their spec: size, bleed, crop marks, CMYK, fonts and image resolution. It runs in the browser, so the file never gets uploaded.

pdf.js, plain JavaScript, Spanish and English

Concept · a made-up jeweller

Halloran, a goldsmith's commission site

For a made-up Dublin jeweller: plan a ring, the book of how it was made that comes with it, turned a page at a time, and type a name to see it cut in Ogham on a gold band in 3D, inside or across the edge.

Astro, three.js

Tools

TypeScript, JavaScript, React, React Native, Next.js, Node, Electron, PostgreSQL, SQLite, AWS, Docker, Cloudflare (Workers, KV, Tunnels, Access), PostHog, Claude Code, Codex.