Principal Software Engineer at eMed UK

Clive Shirley Architecture, code and shared understanding

I design and ship safe changes in regulated systems: payments, healthcare interoperability, multi-region platforms and AI-assisted delivery.

I help teams work through difficult technical decisions, make the trade-offs explicit and put those decisions into practice. I stay hands-on with design, code and review, sharing what I know and learning from the people closest to the problem.

Get in touch About me
Portrait of Clive Shirley
Hampshire, UK

Selected impact

Outcomes, not just output

One contract
pricing & checkout

Replaced separate price configurations with a shared pricing API and shipped multi-account payment routing and a partner configuration portal.

4M+
patient records

Decommissioned a UK telehealth platform with GDPR-safe exports and an immutable, access-controlled media vault.

70M+
messages a day

Real-time Twitter firehose ingestion, ranking and anomaly detection for electronic trading firms at FSWire.

Selected work

Decisions put into practice

What needed to change, what I contributed and what happened next. Sometimes the right outcome is not to build.

Payments as a platform, not a one-off integration

Delivered

Problem
Provider-coupled payment code and separate price configurations made each checkout change harder to reason about.
Decision & contribution
I designed and built a shared pricing API, multi-account payment adapters and the first partner configuration portal, rather than adding another bespoke checkout path.
Outcome
The pricing API and portal are in production. I handed portal development to another engineer so the platform could grow beyond its first release.
Read the write-up

Fix developer experience before re-platforming

Delivered

Problem
Running one service locally still depended on shared environments. A new runtime alone would not give engineers an isolated development loop.
Decision & contribution
I compared the options and built Medley: a one-command local stack with explicit dependencies and readiness checks, reusing Tilt rather than building a process supervisor.
Outcome
Medley became part of engineering onboarding and moved into the backend monorepo. The runtime decision remained separate from the local-development fix.
Read the write-up

Identity: the right outcome was not to migrate

Decision made

Problem
A lower licence bill made replacing the identity provider look attractive, before migration effort and ongoing ownership were counted.
Decision & contribution
I wrote the build-vs-buy analysis, including operating cost, engineering effort and migration risk, to make the decision explicit.
Outcome
The business retained the incumbent after commercial renegotiation. My contribution was the analysis; commercial owners made the decision and negotiated the agreement.

What I do

Where I add the most value

I help teams change how platforms take payments, handle patient data and operate across borders, without losing sight of reliability or the people maintaining them.

Architecture & modernisation

Evolving monoliths into platforms without stopping the business, with decisions written down so they stay reviewable.

  • ADRs
  • DDD
  • Strangler Fig
  • CQRS
  • Event-driven

Payments & pricing

Multi-provider, multi-region payment domains, configuration-driven pricing and zero-downtime provider migrations.

  • Stripe
  • Braintree
  • BACS
  • Adapters
  • B2B2C

Healthcare interoperability

HL7 FHIR domain modelling, e-prescribing and signing, and pharmacy claims submission and reconciliation.

  • HL7 FHIR
  • AES/PAdES
  • NCPDP
  • X12 835

Scale & reliability

Back-pressure, bulkheads, autoscaling signals, graceful shutdown, load testing and cost-aware architecture.

  • Kubernetes
  • HPA
  • DynamoDB
  • Postgres
  • Kafka

Security & data residency

Application security, credential rotation, GDPR operations and residency-clean, per-region stacks for new markets.

  • GDPR
  • HIPAA-aligned
  • AWS KMS
  • OIDC/SAML

AI-assisted engineering & delivery assurance

Contract-led workflows and independent review, alongside research into delivery risk and proposed controls for agent-built changes in regulated production.

  • ACCORD
  • Independent review
  • Release evidence
  • Risk-tiered controls

Open source · MIT

ACCORD: reach agreement before you build

ACCORD is an open-source workflow for AI-assisted software delivery. It makes the request, acceptance criteria and plan explicit before implementation, then checks the result against those criteria.

Run it from the accord CLI with Claude Code, Cursor or Pi, or install the Pi extension for a /accord command inside Pi. It is built around one metric: how little of an engineer's attention it consumes.

  • Orchestration lives in a CLI, not a prompt, so any agent harness can do the work
  • Phase agents run in isolated processes with schema-validated JSON state
  • Adversarial test review (Crucible) runs before any production code exists
  • Two deliberate human gates: contract approval and PR review
  • Per-acceptance-criterion evidence instead of “tests pass, ship it”
View on GitHub

Experience

34+ years, from law firms to trading floors to healthcare

Full career history
  1. Sep 2023 – present

    Principal Software Engineer · eMed UK (continued Babylon’s UK business)

    Own technical strategy and architectural direction for a global healthcare platform. As architecture lead across all engineering pillars, set cross-cutting architecture, reference patterns and standards, and bridge commercial intent and technical delivery through B2B2C expansion, GLP-1 product lines, US and Canadian market entry and the Babylon legacy sunset.

  2. 2018 – Aug 2023

    Principal Software Engineer · Babylon Health

    Set architectural direction and standards for the engineering organisation while hands-on in the core platform.

  3. 2014 – 2018

    Lead Software Engineer · Smarta

    Led in-house and offshore teams delivering white-label small-business SaaS for Lloyds Banking Group and RBS, combining architect and lead-engineer responsibilities.

Writing

Notes from the build

Architecture, delivery and the occasional war story, from real-time finance to regulated healthcare. For the practical takeaways, browse engineering lessons.

All posts

Start here

Latest writing

Contact

Let's compare notes

Working through a difficult platform change, a payments problem or AI-assisted delivery? I'd welcome a conversation about what you're trying to achieve and where I could help.

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