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FACTORY TOUR
The AI Backend Runtime QA Engineer

Verify & secure everything
your agents ship.

Kerno independently tests your critical flows locally against your real stack. Catch runtime and security bugs inside the agent loop before they merge.

Get started free →Kerno in 60s
Your agentsKerno
DWG K-00Kerno runtime QA · line layout
Rev2026.10
Scale1 : 1
Sheet1 of 10
Scroll to enter the factory

Agents and engineers at these companies use Kerno

Field report · 01On the line
Kerno was up and running in minutes with no manual work, and it made our API migration so much smoother. We could instantly validate that every change made by Cursor worked the way we expected, and now it’s a core part of how we build.
Misch StrotzCo-Founder & CEO
LetzAIVerified customer
Field report · 02On the line
Using Kerno with Claude Code has been a game changer. You get quick feedback with no manual effort, and it saves you a lot of time and hassle debugging integration issues post-merge.
Jonathan BernalesCTO
GermenVerified customer
Field report · 03On the line
Kerno saves us a lot of manual work and helps us catch side effects and issues that would definitely break our projects’ backends. Our engineering team loves it.
Santiago J. VallsCo-Founder & CTO
BewiseVerified customer
Field report · 04On the line
Regressions have always been a huge bottleneck for our team. Kerno has been a force multiplier helping us ship releases much faster without the manual overhead of QA.
Ronan HigginsCTO
VeritageVerified customer
1 of 4
Counter A
6×

Faster merges for PRs tested by Kerno

Counter B
48%

More runtime issues caught

Counter C
10h

Freed up per engineer, every week, to build

Hall 01 · The jamWhere things break.
Bay 01The jam

Slow feedback loops are killing
your engineering velocity

The bottleneck isn't writing code. It's proving it works at runtime. Verification happens hours later in CI, where slop piles up, draining engineering time, forcing expensive rework and slowing releases.

DORA metricsSimulated
Lead time▲
9.6 d
Production incidents▲
12 / wk
Change fail▲
38%
Rework / wk▲
$44k
PR gatewaiting on review
CIfailing on main
Sector J · queueFig. 01
Alerts boardFound after merge
FAILworkflowretried charge double-charges across services
FAILauthzleaks records across tenants at runtime
FAILsecuritySSRF via callback URL hits internal metadata
FAILcontractconsumer still reads a field renamed in v2
FAILresiliencedownstream 503 not retried; cascades to a 500
FAILmcptool returns 200 empty body, not an error
Hall 02 · Kerno hallLocal runtime validation.
Bay 02New building unlocked

The Runtime Quality & Security layer for your backend

Give every developer and agent staff-level testing knowledge to catch the expensive runtime issues DIY testing and code review miss, right at the source.

Module A · Real evidenceINSTALLED ✓

Verify every code change against your live stack & dependencies

Kerno catches the functional and security bugs that only surface at runtime, before they ship.

Module B · E2E coverageINSTALLED ✓

Verifies every critical flow a code change touches

Kerno maps a change's blast radius and verifies each flow end to end.

Module C · Consistent qualityINSTALLED ✓

Bring the same high quality verification loop to every engineer

Kerno gives coding agents structured signals and persistent code context on every change.

Kernoruntime QA
Your local stackPostgres · ClickHouse · Kafka · app
New building unlockedKerno, your runtime QA engineer
Plot K · runtime QAFig. 02
Hall 03 · The lineEvery flow, end to end.
Bay 03The line

Kerno tests your critical flows end to end and evolves with your product

Kerno writes and runs tests for your critical user flows and every entry point behind them, so your team catches real bugs at the source before they ship.

Baseline recordedAll critical flows covered✓ checkout4 steps✓ refund-an-order3 steps
Diff on flowcheckout · step 03 · POST /payments- "charges": 1+ "charges": 2
Self-healedintended change · PR #4821UPDATED 2 testsADDED   1 flow
PR #4821 · checkout
  1. 01
    Step 01 · MapDone ✓

    Understand your product

    Builds a graph of your codebase and docs, maps every entry point and the dependencies behind it, and maps your critical user flows with you.

  2. 02
    Step 02 · TestDone ✓

    Test your critical flows end to end

    Tests each user flow as one journey across your APIs, then covers every entry point behind it in depth.

  3. 03
    Step 03 · VerifyDone ✓

    Verify the full impact of changes

    Re-runs every flow a change touches and shows the step that broke, with the outcome the user expected and what actually happened.

  4. 04
    Step 04 · HealRunning

    Self-heal and evolve with your code

    Updates entry-point tests as your product changes and re-generates flows when behavior changes on purpose.

Hall 04 · InspectionWhat Kerno verifies.
Bay 04Inspection

Catches the bugs that only appear at runtime inside the agent loop

Static review reads your code and unit tests run on mocks. Kerno catches the functional, security, and edge-case bugs that only surface at runtime.

Fig. 04 · PR #4821
Unit testsCode reviewRuntime issue
1 ISSUE

End-to-end user flows

Verify complete user journeys across your APIs, from the first request to the outcome read back from your system.

Gate 0131 checks

Contract & schema validation

Validate request and response structures, data types, required fields, serialization rules, and version compatibility.

Gate 0224 checks

Authorization & authentication

Review token validation, role-based access rules, permission scopes, session handling, and all credential-related flows.

Gate 0318 checks

Security · OWASP Top 10

Validate broken object- and function-level authorization, injection, excessive data exposure, mass assignment, and SSRF.

Gate 0419 checks

Boundary & edge cases

Validate payload size limits, pagination behavior, null or empty values, malformed inputs, and constraint-based validation.

Gate 0515 checks

Error handling & resilience

Validate status codes, error body formats, retry behavior, backoff procedures, timeout handling, and controlled fallbacks.

Gate 0612 checks

MCP server testing

Verify each tool your MCP server exposes, including returned content, structured output, schema conformance, and error handling.

Gate 079 checks

AI agent testing

Verify how your agent calls tools, chains model steps, and handles streaming responses, with model providers mocked for deterministic runs.

Gate 08COMING SOON
Hall 05 · Supply depotsWorks with any stack.
Bay 05Supply depots

Works with your stack

Kerno connects to the services and datastores you already run and manages the data layer so it can exercise them the way your application does.

CARGO MANIFEST · KRN-05
Languages11 items
L01TypeScriptL02JavaScriptL03PythonL04JavaL05GoL06RustL07C#L08CL09KotlinL10RubyL11PHP
Data & messaging8 items
D01PostgreSQLD02MySQLD03MariaDBD04MongoDBD05ClickHouseD06RedisD07KafkaD08RabbitMQ
Cloud3 items
C01AWSC02AzureC03Google Cloud
Depot S · real dependenciesFig. 05
EVIDENCE · PR #4821POST /pay → 200 OK, customer charged ×2This ran against your live app locally.
Hall 06 · Work ordersYour house. Your rules.
Bay 06Work orders

Kerno learns your business and standards

It learns your domain logic, your conventions, and your standards, then applies them on every change.

Define custom rules

Give Kerno your standards and business rules in plain English, scoped to the repos and paths you choose. It applies them on every run.

Fig. 06a · rule gate
Work order · Rule 01Scoped
RULEFree-plan organizations retain event data for 30 days and paid plans for 90. Never return events older than the org's plan allows.REPOgetsentry/sentryPATHSsrc/sentry/api/**
Applies to every run in scopeENFORCED

Learns from your feedback

Kerno learns from every test run and the feedback you give it, building a sharper model of your codebase and standards over time.

Fig. 06b · lessons store
Lessons learnedLog 06
Refunds over $10k return pending_approvalL-001
Deletes respond 200 with the record, not 204L-002
A user's 6th org invite is refused with 403L-003
Forbidden records return 404, not 403L-004
Hall 07 · Control roomWhere you see it all.
Bay 07Control room

Know where every application stands,
across every team

CONSOLE 07 · RUNTIME CONTROL
PWRLINKALARM
AAcme
AnalyticsCoverageRunsBehaviour DriftReposSETTINGSProfileOrganizationTeamAPI KeyIntegrations
DocsContact UsCommunity Support
Overview · last 30 daysAnalytics
All RepositoriesLast 30 days
Flows covered52 of 64+4
Entry points covered1,046 of 1,284+4 pts
Code changes tested1,248+212
Potential issues caught87+11
Tests in your suite3,412+286
Active developers18+3
Code changes tested
No diffsPotential issue caught
Repos with most code changes tested
acme/web-app412
acme/billing-api296
acme/orders-svc221
See all test runs →
Potential issues caught
Runs where a test stopped matching its baseline
Repos with most potential issues caught
acme/billing-api29
acme/orders-svc21
acme/web-app17
See all potential issues →
CoverageCoverageThe user flows and entry points Kerno tests, and which ones have tests today.
All Repositories
User flows64 across 6 repos · 52 covered · all branches
All 64Covered 52Not covered 12Search flows
FLOWCOVERAGESTEPSLAST RUN
An org admin filters the billing dashboard to paid invoicesCovered4 stepsjust now
A finance user exports this month's invoices to PDFCovered3 stepsjust now
A customer checks out and is charged exactly onceCovered3 steps1h ago
Support refunds a charge and the invoice updatesCovered4 steps1h ago
Entry points1,284 across 6 repos · 1,046 with a baseline · on default branches
KINDENTRY POINTBASELINEFLOWSREPOLAST RUNCRITICAL
HTTPGET /api/invoicesBaseline6acme/billing-apijust now
HTTPPOST /api/chargesBaseline5acme/billing-api1h ago
HTTPPOST /api/refundsBaseline3acme/billing-api1h ago
HTTPDELETE /api/customers/{id}No baseline–acme/web-app–
Consumercharge.retryBaseline3acme/billing-api1h ago
Behaviour drift · last 30 daysBehaviour DriftHow the tests behind each flow and entry point changed, period by period.
All RepositoriesLast 30 days
Show All changes Added Updated Removed Test changes per period Less More
User flows 9 with test changes
11 Sept16 Sept21 Sept26 Sept1 Oct6 Oct
A customer checks out and is charged exactly once
Support refunds a charge and the invoice updates
Entry points 143 with test changes in the last 30 days
HTTPPOST /api/chargesacme/billing-api
HTTPPOST /api/refundsacme/billing-api
MCPget_order_statusacme/orders-svc
Consumerorder.shippedacme/notifications
HTTPPATCH /api/customers/{id}acme/web-app
HTTPGET /api/ordersacme/orders-svc
HTTPPOST /api/sessionsacme/auth-service
HTTP · acme/web-appPATCH /api/customers/{id}Added 6Updated 2Removed 19 test changes · 6 Oct · 2 runs · main
Added · 6
Nothing to updateValidationSuspected bugPATCH with no changed fields returns 200 and bumps updated_at instead of 304.main · 8c41e07 · 6 Oct 2026
Open report
IDOR attempt blockedAuthorizationA customer can't update another customer's record by changing the id.main · 8c41e07 · 6 Oct 2026
Open report
Mass assignment protectionValidationFields outside CustomerUpdate (plan, credit_limit) can't be set here.main · 8c41e07 · 6 Oct 2026
Open report
No payment details in the responseSecurityThe response never includes card or billing-token fields.main · 8c41e07 · 6 Oct 2026
Open report
Email change needs verificationEdge CaseThe old email stays active until the new one is confirmed.main · 8c41e07 · 6 Oct 2026
Open report
MODE SELECT
01 ANALYTICS
02 COVERAGE
03 DRIFT
FLOW COVERAGE86%
MCP LINK ON
SELF-HEAL ON
Hall 08 · Shift scheduleGetting set up.
Bay 08Shift schedule

Your critical flows covered in under a day

Install Kerno, map your critical flows, and roll out to your team without any friction. Set up once.

Shift 01
First hour

Install, calibrate and map your flows

Point Kerno at your repo. It maps every entry point, connects to your running app and its dependencies, and maps your critical user flows with you.

Shift 02
First day

Cover your critical flows

Kerno tests each critical flow end to end and builds baseline tests for every API, task and event behind it.

Shift 03
First week

Roll out to your team

The Kerno MCP connects to your agents, validating every code change and re-running the flows it touches before they reach production.

Hall 09 · Help deskQuestions.
Kerno operator manual · Rev. 2026.10Section 9 · p. 09
Desk 09Help desk

Questions from the floor

Anything else? Ask in the community channel or read the docs.

§ 9.1What does Kerno actually test?

Your critical user flows, end to end, against your live stack. Kerno also tests every entry point behind them, including HTTP APIs, MCP tools, background tasks and message queues.

§ 9.2How is this different from unit tests or static analysis?

Static review reads your code and unit tests run on mocks. Kerno runs your actual code against your live stack and real dependencies, so it catches runtime behavior that neither one can see.

§ 9.3Which coding agents does Kerno work with?

Kerno connects over MCP to any coding agent, including Claude Code, Codex, Cursor, GitHub Copilot, and more.

§ 9.4Is my code safe?

Kerno encrypts everything end to end and never retains your code, and a SOC 2 Type 2 audit is in progress. Your private code is never stored or used for training.

Hall 10Dispatch

Last stop: production.

DOCK 10 · TO PRODUCTION
DEPARTURESALL VERIFIED
#4821payments-apiidempotent charge retriesDEPARTED ✓
#4822auth-servicerotate refresh tokensDEPARTED ✓
#4823orders-svcsplit fulfillment workerDEPARTED ✓
PR #4821 · VERIFIED
Shift starts now

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Verify & secure everything your agents ship.

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