Grace Owen

S

Engineering Manager, Hartwell Financial - PCI DSS · idempotency · Kafka

Hartwell Financial
London, UK · GMT (UTC+0)
9+ years experience
Saïd Business School
English
Co-founderHiring
Messaging unavailable

Overview

I've spent 9 years on payments infrastructure - first at Sky, now at Hartwell Financial. Led the migration of 64 services to Kafka. Before that: Meta and GSK. Most at home with Kafka and PostgreSQL. I write a small newsletter about payments infrastructure.

Good reasons to reach out
  • People who want to build this with me
  • Candidates for the role I'm hiring for
  • Working sessions on CSS
  • Speaking or podcast invitations
  • Questions about payments infrastructure
Please don't message about
  • Recruiters for roles outside my stack
  • Unpaid work or spec projects

Fastest replies in the morning

Skills
CSSPostgreSQLPCI DSSidempotencyKafkagRPC
Co-founderLooking for a co-founder
closes in 3 months

Looking for a technical co-founder for inventory forecasting for nonprofits

The idea
Inventory forecasting for nonprofits
Stage
Early revenue
I bring
9 years in payments infrastructure
Looking for
Commercial co-founder who has sold to enterprises
Commitment
Part-time to start
Location
London or remote

I bring 9 years of payments infrastructure (currently Hartwell Financial). Ideally you've run operations in MENA. Have a working prototype and design partners.

London, UK · remote OKgrpccssidempotency
Open
HiringHiring for a role
closes in 3 months

Hiring a founding frontend engineer for the payments platform team - London

Role
Founding frontend engineer
Level
Senior
Type
Full-time
Work mode
On-site
Compensation
$183k-$238k + equity
Team
Payments platform, 15 people
Start
Within a month
Must have
Production experience with PCI DSS Production experience with gRPC Good judgment about what not to build
Process
Intro call, technical deep dive, team chat

Comp £75k-£156k. We decide within ten days. Message me with one thing you shipped that you're proud of.

London, UKpostgresqlpci dssidempotency
Open

Experience

  1. Engineering Manager
    Mar 2026 - Present
    Hartwell Financial · 7 mo · Full-time · London, UK
    • Built the experimentation framework 15 product teams use to ship changes safely.
    • Moved 76% of payments platform traffic off a legacy monolith without a customer-facing incident.
    • Designed the reconciliation system that matches 5 million transactions a day.
  2. Senior Backend Engineer
    Jun 2022 - Mar 2026
    Meta · 3 yr 9 mo · Full-time · London, UK
    • Built the experimentation framework 30 product teams use to ship changes safely.
  3. Senior Backend Engineer
    May 2020 - Jun 2022
    GSK · 2 yr 1 mo · Full-time · London, UK
    • Shipped a rewrite that took build times from 19 minutes to under 2.
  4. Backend Engineer
    Dec 2017 - May 2020
    Sky · 2 yr 5 mo · Contract · London, UK
    • Took payment success rates from 95.3% to 96.9%.
    • Shipped 25 launches on the payments platform team without a rollback.

Projects

Write-up: payments infrastructure in practice
2026

A long-form guide to payments infrastructure for people starting out.

References

No references yet.

Education

  1. Saïd Business School
    MBA, Business Administration
    2018 - 2020
  2. University of Manchester
    BSc, Computer Engineering
    2013 - 2016

Details

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