Author
Ihor Seleznov
Engineer at TechFabric
15 posts
How we balance rows between Bronze, Silver and Gold
Our row counts added up while one receipt was missing and another was counted twice. The SQL count per arrival ID that caught it, and the daily Gold check.
Ihor SeleznovReadHow we block AI releases when MLflow scorers fail
A scorer that crashed on two wrong answers raised our MLflow evaluation score from 0.75 to 1.00. We built a release rule that counts coverage first.
Ihor SeleznovReadHow we test that AUTO CDC keeps the right customer record
A Databricks CDC flow can finish green and still keep a customer's old city or bring a deleted customer back. How we test ordering and deletes before release.
Ihor SeleznovReadHow we catch wrong AI answers before they reach customers
An AI step in a Databricks job can report success while tickets get no category or the wrong one. How we catch both before the results reach the support team.
Ihor SeleznovReadCatching a false success in Databricks notebook CI
A test can catch a broken data rule and the release still goes out green. We reproduced that false success and built a runner that stops it.
Ihor SeleznovReadHow we tested data quality rules against twelve defects
A data quality suite can pass every day and still let a duplicate order into the revenue report. We fed our rules twelve defects to find which got through.
Ihor SeleznovReadHow we designed a release gate for Databricks data quality
A failed Databricks quality check doesn't stop bad data reaching reports on its own. We designed a release gate that does, and tested it on six cases.
Ihor SeleznovReadCustomer-held encryption keys on Azure Postgres Flexible Server
Cross-tenant customer-managed keys let a customer hold the key to their data in a provider's Azure Postgres app. What saying yes costs, and how we'd build it.
Ihor SeleznovReadAgent 365 and API Management for MCP tool governance
Agent 365 with API Management lets a company decide in one place which tools its AI agents may use. What it covers, set against our own MCP server.
Ihor SeleznovReadThe cost dashboard said the workspace was fine
A Databricks cost dashboard shows spend. A two-week Health Check finds the spend that bought nothing, from all-purpose clusters to orphaned schedules.
Ihor SeleznovReadDatabricks Repos for QA test automation workflows
Moving QA off ad-hoc notebooks and onto version-controlled test automation with Databricks Repos. Repo structure, modular tests, and how a team works in one.
Ihor SeleznovReadUsing PyTest for Data Quality Checks Directly within Databricks
Writing PyTest data quality checks inside Databricks notebooks. Bronze-to-silver validation, edge cases, fixtures and error handling, with examples.
Ihor SeleznovRead3 Ways To Run Automated Tests On Azure DevOps
Catch bugs before production by running tests automatically in Azure DevOps. Unit tests on CI, Selenium on release, Test Plans on demand, with the YAML.
Ihor SeleznovReadA wide configuration for running Cypress in GitHub Actions
How to make one test suite check every release in each environment, browser and screen size your customers use, from GitHub Actions, without rewrites.
Ihor SeleznovReadThe effects of Cypress component testing on your React app
Cypress component testing catches a broken React form in a test that runs in about a second, long before QA. A working setup on Vite, and when to use it.
Ihor SeleznovRead