Upgrade Triggers: Mandatory, Locking, Opportunity
A Dependabot PR, an EOL notice and a CVE bulletin share one queue but not one urgency. Sort signals into three types and give each a response time.
Engineering
A notebook on backend and systems engineering.
About Muhammet Şafak and the Engineering section — why it exists, where it is going, what gets written here and what does not.
How every piece is built
- 01 Context
- 02 Constraint
- 03 Approach
- 04 Pitfalls
- 05 Expiry
Latest
Notes, system write-ups and essays in one stream, newest first.
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- Essay 5 sections
Which Test Catches the Production Bug?
The real payoff of unit and integration tests: which one actually prevents production bugs, and where to spend your testing budget.
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The Cost of Deferring an Upgrade
A PHP 7.1 → 8.2 upgrade was put off because "it works." The bill came later: a dependency lock, batched breaking changes, and bugs spread over months.
- Essay 5 sections
Chasing 100% Coverage With Tests That Do Nothing
Test coverage is not a target, it's a byproduct. The cost of tests written to push the number up that catch no bugs at all
- Essay 5 sections
The Cost of Installing a Package for Everything
The security, maintenance, and supply-chain cost of adding a dependency for a small function — and when writing it yourself is cheaper
- Note 6 sections
CQRS: When You Need It, When It's Dead Weight
Separating read and write models: the clarity CQRS buys in a complex domain, and the dead weight it adds to plain CRUD
- Note 6 sections
An Archiving Strategy: Old Data Without the Slowdown
Separating old records that bloat the live table: partitioning, cold storage, and keeping query access while you archive
- Essay 5 sections
Is Your Data Really Big, or Just Badly Modeled?
Most big-data problems are really bad modeling or a missing index; before moving to a distributed system, ask whether the data is actually big
- Note 7 sections
Sizing a PostgreSQL Queue Table by Its Live Set
On a queue table, an index and an autovacuum threshold that grow with the table scale wrong; the measured case for sizing both to the pending jobs
- Essay 5 sections
ORM or Native SQL?
Is the ORM making us lazy, or actually protecting us? The balance of safety, readability, and performance between the two approaches
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Indexes: Too Few Slow Reads, Too Many Kill Writes
A missing index slows the query; too many indexes make every write expensive. Striking the right balance by measurement, not by guesswork
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Changing Schema in Production With Zero Downtime
Running migrations without causing downtime in production: backward-compatible steps, multi-phase column changes, and avoiding table locks
Series
Articles that develop one topic part by part.
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PostgreSQL in Production
Keeping a single PostgreSQL cluster healthy in production: connection pooling, backups, read/write splitting, zero-downtime migrations and restore testing.
5-part series
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Upgrading in Production
Treating runtime, framework and dependency upgrades as a risk decision: triggers, inventory, decision matrix, rollout and the decision not to upgrade.
2-part series
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About this section
Vision
What Turkish technical writing is missing is not another introduction; it is a reference an engineer can return to when the same decision lands on their desk. That is where the Engineering section is going: an archive of decisions that still show which constraint produced them, years after they were made.
I measure that three ways. A piece cited as a source in Turkish engineering conversations. An engineer who arrived for a tool staying for the writing. A site that opens like documentation rather than like a marketing page.
The notebook will get larger. It will not get faster.