Skip to content
KubeForge

Hands-on technical assessments

Hire the engineer who can actually fix it.

Candidates get a real, deliberately broken environment and a clear task. They investigate, repair and validate it the way they would in production, while you get the evidence.

Every Kubernetes lab includes

  • A fresh, isolated cluster created for the candidate and destroyed afterwards
  • A browser terminal with kubectl and the tools the task needs
  • Node-level shell access for kubelet, runtime and control-plane labs
  • A time limit and automated validation on submit
  • Recorded command history for reviewers

For hiring teams

Better signal, with less of your engineers' time

Practical assessments filter early and give interviewers something concrete to discuss.

See real working method

How the candidate gathers evidence, forms hypotheses and narrows the fault.

Compare consistently

Same environment, same fault, same checks for every candidate on a role.

Save senior time

Your engineers interview fewer, better-qualified candidates.

Decide on evidence

Check results and command history, not a general impression.

Workflow

How an assessment runs

  1. 01

    Define the role

    Pick labs from the catalogue for the role and level, or ask us to recommend a set.

  2. 02

    Invite the candidate

    The candidate receives a private link. No account or software is needed.

  3. 03

    Candidate works the problem

    A fresh environment is created with the fault injected. The timer starts when they begin.

  4. 04

    Review the results

    Automated checks run on submit. You receive scores, evidence and reviewer notes.

Roles and difficulty

Matched to the seniority you are hiring for

Labs are levelled internally. Candidates see the task, not the difficulty rating, so the level does not change how they approach it.

  • Junior

    Reads errors and events, fixes common workload faults, and follows a methodical process.

  • Mid-level

    Diagnoses across components (DNS, Services, storage, RBAC) and validates the fix independently.

  • Senior

    Works at node and control-plane level, handles ambiguity, and avoids collateral damage.

  • Lead / Architect

    Designs for failure: availability, isolation, security controls and safe operational change.

Roles covered: DevOps Engineer, Platform Engineer, SRE, Kubernetes Engineer, Cloud Engineer, CI/CD and Release Engineer, AI Infrastructure Engineer.

Lab catalogue

Example lab scenarios

Ready-made labs run from our library today. Tailored labs are example scenarios we build around your stack. Every area is also covered in expert interviews.

Ready-made labTailored lab

Showing 53 of 53 labs

  • Kubernetes troubleshooting

    Ready-made lab

    CrashLoopBackOff after a release

    A worker keeps crashing after a deploy. Find the cause from events and logs and make it healthy.

    Pod lifecycleLogs & eventsConfiguration
    Junior · Interview + lab ~15 min
  • Kubernetes troubleshooting

    Ready-made lab

    Pod stuck in Pending

    A routine change left an API with no running Pods. Get it scheduled and serving again.

    SchedulingResource requestsEvents
    Junior · Interview + lab ~15 min
  • Kubernetes troubleshooting

    Ready-made lab

    ImagePullBackOff and a stalled rollout

    A CI change shipped a bad image reference and the rollout has stalled.

    DeploymentsImagesRollouts
    Junior · Interview + lab ~15 min
  • Kubernetes troubleshooting

    Ready-made lab

    CreateContainerConfigError

    A service will not start after a configuration clean-up.

    ConfigMapsSecretsEnv injection
    Junior · Interview + lab ~15 min
  • Kubernetes troubleshooting

    Ready-made lab

    Service cannot reach its Pods

    Pods are healthy but nothing reaches them through their Service.

    ServicesSelectorsEndpoints
    Mid-level · Interview + lab ~15 min
  • Kubernetes troubleshooting

    Ready-made lab

    Cluster DNS is down

    Service names stopped resolving everywhere. Restore DNS and prove it works from a Pod.

    CoreDNSService discoveryValidation
    Mid-level · Interview + lab ~15 min
  • Security

    Ready-made lab

    RBAC permission denied

    A reporting job gets 403 Forbidden from the API. Restore access with least privilege.

    RBACServiceAccountsLeast privilege
    Mid-level · Interview + lab ~20 min
  • Kubernetes troubleshooting

    Ready-made lab

    Liveness probe kills a slow starter

    A service restarts every few seconds although its logs look normal.

    ProbesStartup behaviourReliability
    Mid-level · Interview + lab ~20 min
  • Kubernetes troubleshooting

    Ready-made lab

    PersistentVolumeClaim stuck in Pending

    After a storage migration a service has no volume and will not start.

    PVCsStorageClassesProvisioning
    Mid-level · Interview + lab ~20 min
  • Kubernetes troubleshooting

    Ready-made lab

    Bad release and a stuck rollout

    A release never becomes ready and capacity is down. Roll back safely and record what happened.

    RolloutsRollbackIncident notes
    Mid-level · Interview + lab ~15 min
  • Kubernetes troubleshooting

    Ready-made lab

    Node maintenance gone wrong

    After a maintenance window nothing new schedules. Restore capacity without disturbing running work.

    TaintsCordon & drainScheduling
    Mid-level · Interview + lab ~15 min
  • Kubernetes troubleshooting

    Ready-made lab

    NetworkPolicy outage

    A hardening change took a frontend offline. Restore exactly the traffic that is needed.

    NetworkPolicyTraffic flowsLeast privilege
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    Broken admission webhook

    Scaling does nothing and no new Pods appear. Nobody touched the Deployment.

    Admission controlWebhooksAPI server
    Senior · Interview + lab ~25 min
  • Security

    Ready-made lab

    Pod Security Admission rejection

    A new exporter release is rejected by the namespace security policy.

    Pod SecuritysecurityContextHardening
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    CoreDNS crashes after a config change

    A DNS configuration change took name resolution down for every workload.

    CoreDNSCorefileChange review
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    ResourceQuota deadlock

    An ingest service cannot reach its required size and keeps losing replicas.

    ResourceQuotaLimitRangeCapacity
    Senior · Interview + lab ~20 min
  • Kubernetes troubleshooting

    Ready-made lab

    New Services do not work

    Existing Services work, but anything created today is unreachable by ClusterIP.

    kube-proxyService networkingNode components
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    Worker node NotReady

    A worker went NotReady overnight. Bring the node back and confirm workloads recover.

    kubeletsystemdNode health
    Mid-level · Interview + lab ~20 min
  • Kubernetes troubleshooting

    Ready-made lab

    kubelet will not start

    A kubelet crash-loops after a config edit. Diagnose from the journal and restore it.

    kubelet configjournalctlsystemd
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    kubelet cannot reach the API server

    The kubelet runs but the node is NotReady and cannot talk to the control plane.

    kubeconfigTLSControl plane
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    Container runtime down

    A node is NotReady and cannot run containers. The runtime is unhealthy.

    containerdcrictlNode debugging
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    DNS broken on one node only

    Some Pods resolve names and others do not. The difference is the node.

    kubeletresolv.confIsolation
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    Node under false disk pressure

    A worker evicts Pods and refuses new ones although its disk is nearly empty.

    Evictionkubelet thresholdsNode conditions
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    API server down

    kubectl returns connection refused. The API server is not coming up.

    Static PodsAPI server flagsControl plane
    Senior · Interview + lab ~25 min
  • Kubernetes troubleshooting

    Ready-made lab

    etcd will not start

    The whole control plane is down because the API server cannot reach its datastore.

    etcdStatic PodsRecovery
    Senior · Interview + lab ~30 min
  • Kubernetes troubleshooting

    Ready-made lab

    etcd database full

    Writes fail with "no space". etcd has hit its storage quota.

    etcdCompaction & defragAlarms
    Senior · Interview + lab ~30 min
  • Kubernetes troubleshooting

    Ready-made lab

    Scheduler down

    New Pods stay Pending forever with no events. Nothing is being scheduled.

    kube-schedulerStatic PodsDiagnosis
    Lead / Architect · Interview + lab ~30 min
  • Kubernetes troubleshooting

    Ready-made lab

    Controller manager down

    A Deployment was scaled up but no new Pods appear. Controllers are not acting.

    ControllersReconciliationControl plane
    Lead / Architect · Interview + lab ~30 min
  • Kubernetes troubleshooting

    Ready-made lab

    Survive node maintenance

    Make a service ride through a rolling node drain with no dropped requests.

    PDBsTopology spreadGraceful shutdown
    Lead / Architect · Interview + lab ~40 min
  • Platform engineering & GitOps

    Ready-made lab

    Multi-tenant isolation

    Two teams share a cluster with no isolation. Build access, quota and network boundaries.

    RBACNetworkPolicyQuotas
    Lead / Architect · Interview + lab ~40 min
  • Kubernetes troubleshooting

    Ready-made lab

    Autoscaling that will not scale

    An HPA shows unknown metrics and never scales the web tier under load.

    HPAmetrics-serverRequests & limits
    Lead / Architect · Interview + lab ~40 min
  • Security

    Ready-made lab

    Enable API audit logging

    Record access to Secrets in an audit log without leaking their values, with rotation.

    Audit policyAPI serverCompliance
    Lead / Architect · Interview + lab ~40 min
  • Security

    Ready-made lab

    Encrypt Secrets at rest

    Secrets are stored in plaintext in etcd. Enable encryption and re-encrypt existing data.

    Encryption configetcdKey rotation
    Lead / Architect · Interview + lab ~40 min
  • DevOps & CI/CD

    Tailored lab

    Failing GitHub Actions pipeline

    A release workflow fails intermittently after a dependency change. Find the cause and make it reliable.

    GitHub ActionsCachingBuild debugging
    Mid-level · Interview + tailored lab ~30 min
  • DevOps & CI/CD

    Tailored lab

    Image build cannot push

    Builds succeed locally but the pipeline cannot publish images to the registry.

    Container buildsRegistry authSecrets in CI
    Junior · Interview + tailored lab ~20 min
  • DevOps & CI/CD

    Tailored lab

    Canary release gone wrong

    A progressive rollout promoted a bad version. Diagnose the gate and fix the release strategy.

    Deployment strategiesRelease gatesRollback
    Senior · Interview + tailored lab ~40 min
  • Platform engineering & GitOps

    Tailored lab

    Argo CD application stuck OutOfSync

    An application never converges and reports drift on every sync.

    Argo CDSync wavesDrift
    Mid-level · Interview + tailored lab ~30 min
  • Platform engineering & GitOps

    Tailored lab

    Flux reconciliation failure

    A Kustomization fails to reconcile after a repository restructure.

    FluxKustomizeSource controllers
    Senior · Interview + tailored lab ~30 min
  • Platform engineering & GitOps

    Tailored lab

    Helm upgrade fails mid-release

    A chart upgrade failed halfway and the release is stuck in a pending state.

    HelmRelease historyRecovery
    Mid-level · Interview + tailored lab ~25 min
  • Cloud & Terraform

    Tailored lab

    Terraform state drift and lock

    A plan wants to replace production resources and the state is locked.

    Terraform stateImportsLocking
    Senior · Interview + tailored lab ~35 min
  • Cloud & Terraform

    Tailored lab

    Refactor modules without replacement

    Restructure Terraform modules without destroying live infrastructure.

    Modulesmoved blocksPlan review
    Lead / Architect · Interview + tailored lab ~45 min
  • Cloud & Terraform

    Tailored lab

    Cloud IAM access denied

    A workload cannot reach a storage bucket after a policy change.

    IAMWorkload identityLeast privilege
    Mid-level · Interview + tailored lab ~25 min
  • SRE & observability

    Tailored lab

    The alert that never fires

    An outage went unnoticed. Find why the alert stayed silent and fix it.

    PrometheusAlertmanagerPromQL
    Mid-level · Interview + tailored lab ~30 min
  • SRE & observability

    Tailored lab

    Define SLOs and burn-rate alerts

    Turn a vague reliability goal into SLIs, SLOs and actionable alerts.

    SLIs/SLOsError budgetsBurn rate
    Senior · Interview + tailored lab ~45 min
  • SRE & observability

    Tailored lab

    Production latency investigation

    Latency doubled after a deploy. Use metrics and logs to find the cause.

    GrafanaLokiIncident method
    Senior · Interview + tailored lab ~40 min
  • Linux & networking

    Tailored lab

    Disk full on a busy host

    A service fails writes although df shows free space.

    FilesystemsInodesOpen file handles
    Junior · Interview + tailored lab ~20 min
  • Linux & networking

    Tailored lab

    systemd service will not start

    A unit fails at boot with an unclear error.

    systemdjournalctlUnit files
    Junior · Interview + tailored lab ~15 min
  • Linux & networking

    Tailored lab

    Intermittent connection resets

    Clients see random resets and slow DNS between two services.

    TCP/IPDNStcpdump
    Senior · Interview + tailored lab ~35 min
  • Security

    Tailored lab

    Enforce signed images

    Only signed images from a trusted registry may run in production namespaces.

    Supply chainAdmission policySigning
    Senior · Interview + tailored lab ~40 min
  • Security

    Tailored lab

    Secrets exposed in workloads

    Find and remediate credentials leaked through environment variables and logs.

    Secrets managementWorkload securityAudit
    Mid-level · Interview + tailored lab ~25 min
  • AI infrastructure & operations

    Tailored lab

    GPU node not schedulable

    GPU workloads stay Pending on a node that has GPUs installed.

    GPU device pluginNode labelsScheduling
    Senior · Interview + tailored lab ~35 min
  • AI infrastructure & operations

    Tailored lab

    LLM inference server keeps restarting

    A self-hosted model server is OOM-killed under real traffic.

    Model servingMemory sizingProbes
    Senior · Interview + tailored lab ~40 min
  • AI infrastructure & operations

    Tailored lab

    Inference platform design review

    Design-level exercise tailored to your serving stack and traffic profile.

    Inference capacityAutoscalingCost
    Lead / Architect · Interview + tailored lab ~60 min

How automated validation works

When the candidate submits, hidden checks inspect the real state of the environment. They do not look at what the candidate typed; they test whether the system works.

  • Each check tests one outcome, such as “the Service name resolves from the affected Pod”
  • Checks carry points; a pass mark is set per lab
  • Guard checks catch shortcuts such as deleting the broken workload
  • Every lab is tested against a clean, a broken and a repaired environment before release

How human review works

Automated checks show whether it works. A reviewer looks at how the candidate got there, because two passing results can reflect very different engineers.

  • Review of command history: investigation order, risky actions, validation steps
  • Rubric scores for method, accuracy, safety and validation
  • Written comments your hiring manager can read in two minutes
  • Optional follow-up questions for the live interview

Candidate experience

Fair, clear and respectful of their time

Strong candidates often have several offers. The assessment should feel like real work, not an obstacle course.

Browser only

No installs, VPNs or local clusters.

Clear task

A written brief that states what success looks like.

Visible time limit

Most labs take 15 to 40 minutes.

Private and isolated

A dedicated environment that is destroyed afterwards.

Combined assessment + interview

One report that brings lab evidence and interview together

For senior and lead roles, the strongest signal comes from a lab followed by a focused conversation about what the candidate did and why.

  1. 1Candidate completes a hands-on lab.
  2. 2Your team reviews the results and activity.
  3. 3An expert interviewer probes decisions, trade-offs and alternatives.
  4. 4You receive a consolidated evaluation and recommendation.

Evaluation report

Candidate A · Platform Engineer (Senior)

Sample report

Hands-on lab

86 / 100

Live interview

4.0 / 5

Recommendation

Proceed

Troubleshooting method

Reproduced the symptom, then narrowed scope methodically.

Technical accuracy

Correct root cause; fix limited to the faulty configuration.

Validation

Proved the fix from the affected workload before submitting.

Communication

Explained decisions clearly; missed one follow-up risk.

Attached evidence: automated check results, terminal command history, interviewer notes.

FAQ

Common questions

What does the candidate need?
A modern browser and a stable connection. The terminal runs in the browser; there is nothing to install and no credentials to share.
Which areas have hands-on labs?
All of them. Kubernetes and Kubernetes security have 33 ready-made labs that run from our library, covering workloads, networking, nodes, the control plane and etcd. For cloud, Terraform, CI/CD, GitOps, SRE, Linux and AI infrastructure we build the hands-on lab around your stack, and every area is also covered in expert-led interviews.
How is the score calculated?
Each lab has a set of automated checks that inspect the final state of the environment, each worth a number of points. A reviewer can add qualitative comments on approach and method. The score is one input to your decision, not a verdict.
Can candidates use documentation or AI tools?
You decide the rules for each assessment. Labs are designed so that the outcome depends on investigating a specific environment and validating the fix, which rewards real understanding regardless of tools. We do not claim to detect every use of AI assistance.
Can you customise a lab for our team?
Yes. We can adapt any ready-made lab or build a new one around your cloud, tooling, conventions and the incident types your team deals with. Tell us the role and what you want to test; custom lab work is scoped and quoted per requirement.
What data do you keep about candidates?
Only what is needed to produce the assessment report: the candidate's name or identifier, the lab result, checks and command history. Retention periods are agreed with each client. This marketing website does not collect candidate assessment data.

See a lab running on a real cluster.

We will walk you through a live assessment and suggest labs for your open roles.