Testing APIs. Biggest Problems?
Hey there,
What are the biggest issues/problems you currently have with building and Testing APIs with existing tools like Postman, Insomnia etc?
Is it about lack of features? Or maybe too many features? Developer Experience? Security? Anything else?
Nikolas
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We have automations running in the form of shell scripts, that test using curl. Faster, agile, better.
From my experience leading API testing teams, the biggest problems aren’t a lack of tools — it’s the gaps in what people actually test.
Some recurring issues:
Boundary values are almost never tested (min/max, overflow, negative ranges).
ENUM or “allowed values” checks are skipped because they’re boring to maintain.
Developers rely on happy-path requests and miss trimming/whitespace/invalid-type scenarios.
Request/response structure mismatches (one missing field often breaks entire flows).
Reflection issues — APIs echoing back user input and leaking things they shouldn’t.
Security headers missing under certain conditions (rarely tested manually).
Environment drift — staging behaves differently than production, but the tests are identical.
Etc..
Most failures I see in real systems come from very simple inputs nobody bothered to test.