Traditional technical debt—shortcuts in code, outdated dependencies, missing tests—is well understood. AI systems introduce new categories of debt that are less visible but equally dangerous: model drift, prompt rot, data debt, and evaluation gaps.
Here’s how to recognize and manage AI technical debt.
AI-Specific Technical Debt
Categories
ai_debt_categories:
model_debt:
- Outdated models still in use
- Deprecated API versions
- Untracked model dependencies
- Missing model versioning
data_debt:
- Training data quality issues
- Undocumented data pipelines
- Data drift unmonitored
- Missing data validation
prompt_debt:
- Unversioned prompts
- Untested prompt changes
- Duplicated prompt logic
- Hardcoded prompts
evaluation_debt:
- No quality baselines
- Missing regression tests
- Inadequate monitoring
- No golden datasets
infrastructure_debt:
- Manual deployments
- No A/B testing capability
- Missing fallbacks
- Cost untracked
Recognizing the Debt
Warning Signs
warning_signs:
model_staleness:
symptom: "We've been using the same model since launch"
risk: Performance degradation, missing improvements
prompt_chaos:
symptom: "Each engineer has their own version of the prompt"
risk: Inconsistent behavior, hard to improve
evaluation_void:
symptom: "We think it works, but we haven't measured"
risk: Silent quality degradation
data_mystery:
symptom: "We're not sure what data the model was trained on"
risk: Unexplainable failures, bias issues
dependency_ignorance:
symptom: "We just call the API, don't track versions"
risk: Breaking changes surprise you
Debt Assessment
class AIDebtAssessment:
def assess(self, system: AISystem) -> DebtReport:
scores = {}
# Model debt
scores['model'] = self._assess_model_debt(system)
# Prompt debt
scores['prompt'] = self._assess_prompt_debt(system)
# Data debt
scores['data'] = self._assess_data_debt(system)
# Evaluation debt
scores['evaluation'] = self._assess_evaluation_debt(system)
# Infrastructure debt
scores['infrastructure'] = self._assess_infra_debt(system)
return DebtReport(scores=scores, recommendations=self._recommend(scores))
def _assess_prompt_debt(self, system) -> float:
factors = [
system.prompts_versioned,
system.prompts_tested,
system.prompts_centralized,
system.prompt_changes_tracked,
]
return sum(factors) / len(factors)
Managing Model Debt
Model Lifecycle Management
model_lifecycle:
version_tracking:
- Track which model version in use
- Document when deployed
- Record performance at deployment
update_cadence:
- Regular evaluation against new models
- Scheduled review (quarterly)
- Clear upgrade criteria
deprecation_handling:
- Monitor for deprecation notices
- Plan migration before deadline
- Test alternatives proactively
class ModelRegistry:
def __init__(self):
self.models = {}
def register(self, name: str, model_info: dict):
self.models[name] = {
**model_info,
'registered_at': datetime.now(),
'last_evaluated': None,
'deprecated': False
}
def check_for_updates(self):
"""Check if newer model versions are available."""
alerts = []
for name, info in self.models.items():
latest = get_latest_model_version(info['provider'], info['family'])
if latest != info['version']:
alerts.append({
'model': name,
'current': info['version'],
'latest': latest
})
return alerts
Managing Prompt Debt
Prompt Governance
prompt_governance:
centralization:
- Single source of truth for prompts
- Named, versioned prompts
- Shared library/registry
versioning:
- Semantic versioning for prompts
- Change documentation
- Rollback capability
testing:
- Tests for each prompt
- Golden dataset evaluation
- Regression detection
review_process:
- PR review for prompt changes
- A/B testing for significant changes
- Impact assessment
# Prompt registry pattern
class PromptRegistry:
def __init__(self):
self.prompts = {}
self.versions = {}
def register(self, name: str, template: str, version: str):
if name not in self.prompts:
self.prompts[name] = {}
self.versions[name] = []
self.prompts[name][version] = template
self.versions[name].append(version)
def get(self, name: str, version: str = None) -> str:
if version is None:
version = self.versions[name][-1] # Latest
return self.prompts[name][version]
def diff(self, name: str, v1: str, v2: str) -> str:
"""Show difference between prompt versions."""
import difflib
p1 = self.prompts[name][v1]
p2 = self.prompts[name][v2]
return '\n'.join(difflib.unified_diff(
p1.splitlines(), p2.splitlines(),
fromfile=f'{name}@{v1}', tofile=f'{name}@{v2}'
))
# Usage
prompts = PromptRegistry()
prompts.register(
'summarize',
'Summarize the following text in 3 bullet points:\n{text}',
version='1.0.0'
)
Managing Evaluation Debt
Evaluation Infrastructure
evaluation_infrastructure:
golden_datasets:
- Curated test cases
- Regular updates
- Coverage analysis
automated_evaluation:
- CI/CD integration
- Regression detection
- Quality gates
monitoring:
- Production quality tracking
- User feedback collection
- Anomaly detection
class EvaluationPipeline:
def __init__(self, golden_dataset, metrics):
self.golden_dataset = golden_dataset
self.metrics = metrics
self.baseline = None
def run_evaluation(self, model, prompt_version) -> dict:
results = []
for case in self.golden_dataset:
output = model.generate(case.input)
metrics = {
metric.name: metric.evaluate(output, case.expected)
for metric in self.metrics
}
results.append(metrics)
aggregate = self._aggregate(results)
# Check for regression
if self.baseline:
regression = self._check_regression(aggregate, self.baseline)
if regression:
raise RegressionDetected(regression)
return aggregate
def update_baseline(self, results: dict):
self.baseline = results
Paying Down the Debt
Prioritization
debt_prioritization:
critical:
- Security vulnerabilities
- Data privacy issues
- Production failures
high:
- Quality regression
- Cost inefficiency
- Missing monitoring
medium:
- Outdated models
- Untested prompts
- Missing documentation
low:
- Code cleanup
- Minor optimizations
- Nice-to-have tooling
Incremental Improvement
incremental_approach:
each_sprint:
- 10-20% time for debt reduction
- Focus on one category
- Measurable improvement
quarterly:
- Debt assessment
- Prioritization review
- Major initiatives
ongoing:
- Don't add new debt
- Improve what you touch
- Document decisions
Key Takeaways
- AI introduces new categories of technical debt
- Model debt: outdated models, missing versioning
- Prompt debt: unversioned, untested, scattered prompts
- Evaluation debt: no baselines, missing tests
- Data debt: unknown data quality and provenance
- Assess debt regularly with clear criteria
- Centralize and version prompts like code
- Build evaluation infrastructure early
- Allocate time for debt reduction each sprint
- New AI features without governance create debt
AI debt is real. Manage it before it manages you.