Technology

Python Testing& Development

Python powers much of our tooling: pytest-based Automation, API test suites, data validation utilities, and the AI evaluation harnesses behind our LLM Testing practice. When your stack is Python, our Engineers speak it natively, from fixtures to CI plumbing.

Automation, tooling, and AI evaluation harnesses

pytest frameworks with clean fixtures and parallel execution

API and data-validation suites

Custom QA tooling and reporting

AI/LLM evaluation harnesses (our QEAP stack)

Testing
pytest, Playwright for Python, Selenium bindings, requests
Data & evaluation
pandas, SQLAlchemy, custom evaluation harnesses
Where it fits
Data validation, AI evals, internal tooling, CI utilities
Handover
Documented, packaged and runnable by your team in CI

The glue language of a QA practice

Python is where a lot of Quality Engineering work actually happens, even in organisations whose product is written in something else.

Python is where a lot of Quality Engineering work actually happens, even in organisations whose product is written in something else. It is the fastest way to build the thing that does not exist yet: a data reconciliation harness, a synthetic data generator, an evaluation runner for an LLM feature, a CI utility that turns test output into something a stakeholder can read.

We use it for three families of work, test Automation with pytest, Playwright for Python or Selenium bindings where a client's team is Python-first; data and database validation using SQL harnesses that can be re-run in a pipeline; and AI evaluation harnesses that score model outputs against golden datasets.

Automation in pytest, built to be maintained

pytest's fixture model is the best argument for Python Automation: setup scoped precisely to what each test needs, composed rather than inherited, with teardown guaranteed.

pytest's fixture model is the best argument for Python Automation: setup scoped precisely to what each test needs, composed rather than inherited, with teardown guaranteed. Parametrisation turns a table of boundary cases into a table of tests without duplication. Combined with Playwright for Python, you get modern browser Automation in a language your data and platform Engineers already read.

The architecture commitments are the same ones we make everywhere: API-driven test data so specs are independent, a selector contract with the frontend team, and CI integration from the first week. The language changes; the reasons suites fail do not.

Harnesses, tooling and evaluation

The higher-leverage Python work is usually not browser Automation at all.

The higher-leverage Python work is usually not browser Automation at all. It is the reconciliation script that proves a migration moved every row intact. The generator that produces production-shaped test data without moving personal data into staging. The evaluation harness that runs a golden dataset against a prompt on every change and fails the build when grounding or accuracy regresses, the pattern behind our AI Quality Engineering case study and the method in How to Test a RAG Pipeline.

Everything is delivered packaged, documented and runnable by your team, in your repository. A harness only you can run is a consultancy dependency, not a deliverable.

Engagement path

How the engagement runs

How a Python engagement runs from first call to handover.

01

Identify the missing tool

Most Python engagements start from a gap, data nobody can reconcile, evaluation nobody can automate, a report nobody can produce reliably.

02

Build the smallest useful version

A working harness against a real dataset first, so the approach is validated before it is generalised into a framework.

03

Wire it into CI

Packaged, pinned and running in your pipeline on the right trigger, with output a non-specialist can read and act on.

04

Document and hand over

README, contribution notes and a pairing session, so the tool outlives the engagement that produced it.

Deliverables

What you get

Artefacts you keep and can run without us. Everything lives in your repositories and your pipelines.

Handover pack

6 artefacts · yours to keep

01

pytest suites with fixture-scoped setup and parametrised boundary coverage

02

Playwright for Python or Selenium Automation where your team is Python-first

03

SQL-based data validation and reconciliation harnesses, re-runnable in CI

04

Synthetic and masked test data generators for non-production environments

05

LLM evaluation harnesses scoring outputs against a golden dataset

06

Packaged, documented tooling your Engineers run without us

Self-check

Signs your team needs this

If more than one of these is true, it is usually cheaper to fix now than after the next release.

Your platform and data Engineers are Python-first but Automation is not

Data reconciliation is done by hand, in spreadsheets, before each release

An AI feature ships with no automated evaluation of its outputs

Test data is either production data or too clean to find real defects

The reporting that stakeholders need is assembled manually every cycle

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Questions

Frequently Asked Questions

Straight answers, written the way we'd say them on a call.

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16+

Years QA leadership

16

Testing disciplines

6

Markets served

1

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