diff --git a/app/wizard/step_hardware.py b/app/wizard/step_hardware.py
new file mode 100644
index 0000000..339272a
--- /dev/null
+++ b/app/wizard/step_hardware.py
@@ -0,0 +1,14 @@
+"""Step 1 — Hardware detection and inference profile selection."""
+
+PROFILES = ["remote", "cpu", "single-gpu", "dual-gpu"]
+
+
+def validate(data: dict) -> list[str]:
+    """Return list of validation errors. Empty list = step passes."""
+    errors = []
+    profile = data.get("inference_profile", "")
+    if not profile:
+        errors.append("Inference profile is required.")
+    elif profile not in PROFILES:
+        errors.append(f"Invalid inference profile '{profile}'. Choose: {', '.join(PROFILES)}.")
+    return errors
diff --git a/app/wizard/step_identity.py b/app/wizard/step_identity.py
new file mode 100644
index 0000000..644a902
--- /dev/null
+++ b/app/wizard/step_identity.py
@@ -0,0 +1,13 @@
+"""Step 3 — Identity (name, email, phone, linkedin, career_summary)."""
+
+
+def validate(data: dict) -> list[str]:
+    """Return list of validation errors. Empty list = step passes."""
+    errors = []
+    if not (data.get("name") or "").strip():
+        errors.append("Full name is required.")
+    if not (data.get("email") or "").strip():
+        errors.append("Email address is required.")
+    if not (data.get("career_summary") or "").strip():
+        errors.append("Career summary is required.")
+    return errors
diff --git a/app/wizard/step_inference.py b/app/wizard/step_inference.py
new file mode 100644
index 0000000..5df54c8
--- /dev/null
+++ b/app/wizard/step_inference.py
@@ -0,0 +1,9 @@
+"""Step 5 — LLM inference backend configuration and key entry."""
+
+
+def validate(data: dict) -> list[str]:
+    """Return list of validation errors. Empty list = step passes."""
+    errors = []
+    if not data.get("endpoint_confirmed"):
+        errors.append("At least one working LLM endpoint must be confirmed.")
+    return errors
diff --git a/app/wizard/step_resume.py b/app/wizard/step_resume.py
new file mode 100644
index 0000000..705452b
--- /dev/null
+++ b/app/wizard/step_resume.py
@@ -0,0 +1,10 @@
+"""Step 4 — Resume (upload or guided form builder)."""
+
+
+def validate(data: dict) -> list[str]:
+    """Return list of validation errors. Empty list = step passes."""
+    errors = []
+    experience = data.get("experience") or []
+    if not experience:
+        errors.append("At least one work experience entry is required.")
+    return errors
diff --git a/app/wizard/step_search.py b/app/wizard/step_search.py
new file mode 100644
index 0000000..e64633c
--- /dev/null
+++ b/app/wizard/step_search.py
@@ -0,0 +1,13 @@
+"""Step 6 — Job search preferences (titles, locations, boards, keywords)."""
+
+
+def validate(data: dict) -> list[str]:
+    """Return list of validation errors. Empty list = step passes."""
+    errors = []
+    titles = data.get("job_titles") or []
+    locations = data.get("locations") or []
+    if not titles:
+        errors.append("At least one job title is required.")
+    if not locations:
+        errors.append("At least one location is required.")
+    return errors
diff --git a/app/wizard/step_tier.py b/app/wizard/step_tier.py
new file mode 100644
index 0000000..1ca74e6
--- /dev/null
+++ b/app/wizard/step_tier.py
@@ -0,0 +1,13 @@
+"""Step 2 — Tier selection (free / paid / premium)."""
+from app.wizard.tiers import TIERS
+
+
+def validate(data: dict) -> list[str]:
+    """Return list of validation errors. Empty list = step passes."""
+    errors = []
+    tier = data.get("tier", "")
+    if not tier:
+        errors.append("Tier selection is required.")
+    elif tier not in TIERS:
+        errors.append(f"Invalid tier '{tier}'. Choose: {', '.join(TIERS)}.")
+    return errors
diff --git a/tests/test_wizard_steps.py b/tests/test_wizard_steps.py
new file mode 100644
index 0000000..37b6a87
--- /dev/null
+++ b/tests/test_wizard_steps.py
@@ -0,0 +1,112 @@
+import sys
+from pathlib import Path
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+# ── Hardware ───────────────────────────────────────────────────────────────────
+from app.wizard.step_hardware import validate as hw_validate, PROFILES
+
+def test_hw_valid():
+    assert hw_validate({"inference_profile": "remote"}) == []
+
+def test_hw_missing():
+    assert hw_validate({}) != []
+
+def test_hw_invalid():
+    assert hw_validate({"inference_profile": "turbo"}) != []
+
+def test_hw_all_profiles():
+    for p in PROFILES:
+        assert hw_validate({"inference_profile": p}) == []
+
+# ── Tier ───────────────────────────────────────────────────────────────────────
+from app.wizard.step_tier import validate as tier_validate
+
+def test_tier_valid():
+    assert tier_validate({"tier": "free"}) == []
+
+def test_tier_missing():
+    assert tier_validate({}) != []
+
+def test_tier_invalid():
+    assert tier_validate({"tier": "enterprise"}) != []
+
+# ── Identity ───────────────────────────────────────────────────────────────────
+from app.wizard.step_identity import validate as id_validate
+
+def test_id_all_required_fields():
+    d = {"name": "Alice", "email": "a@b.com", "career_summary": "10 years of stuff."}
+    assert id_validate(d) == []
+
+def test_id_missing_name():
+    d = {"name": "", "email": "a@b.com", "career_summary": "x"}
+    errors = id_validate(d)
+    assert errors != []
+    assert any("name" in e.lower() for e in errors)
+
+def test_id_missing_email():
+    d = {"name": "Alice", "email": "", "career_summary": "x"}
+    errors = id_validate(d)
+    assert errors != []
+    assert any("email" in e.lower() for e in errors)
+
+def test_id_missing_summary():
+    d = {"name": "Alice", "email": "a@b.com", "career_summary": ""}
+    errors = id_validate(d)
+    assert errors != []
+    assert any("summary" in e.lower() or "career" in e.lower() for e in errors)
+
+def test_id_whitespace_only_name():
+    d = {"name": "   ", "email": "a@b.com", "career_summary": "x"}
+    assert id_validate(d) != []
+
+# ── Resume ─────────────────────────────────────────────────────────────────────
+from app.wizard.step_resume import validate as resume_validate
+
+def test_resume_no_experience():
+    assert resume_validate({"experience": []}) != []
+
+def test_resume_one_entry():
+    d = {"experience": [{"company": "Acme", "title": "Engineer", "bullets": ["did stuff"]}]}
+    assert resume_validate(d) == []
+
+def test_resume_missing_experience_key():
+    assert resume_validate({}) != []
+
+# ── Inference ──────────────────────────────────────────────────────────────────
+from app.wizard.step_inference import validate as inf_validate
+
+def test_inference_not_confirmed():
+    assert inf_validate({"endpoint_confirmed": False}) != []
+
+def test_inference_confirmed():
+    assert inf_validate({"endpoint_confirmed": True}) == []
+
+def test_inference_missing():
+    assert inf_validate({}) != []
+
+# ── Search ─────────────────────────────────────────────────────────────────────
+from app.wizard.step_search import validate as search_validate
+
+def test_search_valid():
+    d = {"job_titles": ["Software Engineer"], "locations": ["Remote"]}
+    assert search_validate(d) == []
+
+def test_search_missing_titles():
+    d = {"job_titles": [], "locations": ["Remote"]}
+    errors = search_validate(d)
+    assert errors != []
+    assert any("title" in e.lower() for e in errors)
+
+def test_search_missing_locations():
+    d = {"job_titles": ["SWE"], "locations": []}
+    errors = search_validate(d)
+    assert errors != []
+    assert any("location" in e.lower() for e in errors)
+
+def test_search_missing_both():
+    errors = search_validate({})
+    assert len(errors) == 2
+
+def test_search_none_values():
+    d = {"job_titles": None, "locations": None}
+    assert search_validate(d) != []