Türker Yıldırım

system-design

  • A shared database between two services is one service

    Note2 min read

    Two deployables reading and writing the same tables cannot be released independently, cannot change their schema independently and fail together — which is every property a service was…

  • Autowiring, and what the container is allowed to guess

    Deep dive10 min read

    services.yaml went from four hundred lines to twelve. Where the guessing stops is the part worth knowing before it stops in production.

  • A queue table is not a queue

    Deep dive10 min read

    SELECT … WHERE processed = 0 LIMIT 1, and two workers taking the same row. SKIP LOCKED makes the table viable; it does not make it a broker.

  • What the regulation actually asks of a schema

    Deep dive15 min read

    The deadline is in May and the work is not a cookie banner. An inventory first, because everything else depends on knowing which tables hold what.

  • Consent is a record with a timestamp, not a boolean

    Note2 min read

    A marketing_opt_in column stores the current answer and nothing else, and the question that gets asked is always “when, and to what exactly did they agree”. Append-only is…

  • Pseudonymisation is not anonymisation, and the difference is legal

    Note1 min read

    Replacing an email with a hash feels like removing personal data and does not, because the same input always produces the same output and the input space is…

  • Symfony 4 and the bundle that does not exist

    Deep dive10 min read

    A new project used to arrive with forty megabytes of vendor code and one route. The framework got smaller, and the interesting part is what happens at install…

  • A circuit breaker before the third-party outage

    Deep dive10 min read

    A payment provider was slow and the whole site went down with it. A timeout bounds one request; it does nothing about how many are waiting at once.

  • Alerting that people do not learn to ignore

    Deep dive10 min read

    340 alerts in a month, four of which mattered. An alert channel nobody reads is the same as no alerting, and the cause is alerting on causes.

  • Compose file version 3, and what swarm changed

    Deep dive10 min read

    v3 exists to be deployable to a scheduler, and that removes things a single-host file relied on. What went, why it had to, and what replaces it.