Define the boundary
Write down the input, expected output, failure cases and actions that must never happen automatically.
PORTFOLIO / ENGINEERING CASE STUDIES
Proof you can inspect.
Five compact systems, each built around a different operational failure mode. The common thread is explicit boundaries, reproducible tests and handoff that does not depend on hidden context.
Different problems. Same delivery discipline.
DATA RELIABILITY
Data Shape Guard
Detect breaking JSON/JSONL payload drift, protect secret-like examples, reject ambiguous JSON and gate CI by severity.
Read case study → CONTENT SYSTEMSBrief to Page
Keep landing-page decisions in a reviewable JSON brief, validate boundaries first, then render a deterministic single-file page.
Read case study → AUTOMATION RELIABILITYAutomation First Aid
Classify retry safety, validate payloads, probe endpoints safely and expose actionable diagnostic failures to CI or monitoring.
Read case study → WORKFLOW CONTRACTSWorkflow Contract Gate
Validate API and webhook fixtures against explicit contracts, produce secret-safe diagnostics, and fail CI with clear exit semantics.
Read case study → SIDE-EFFECT RELIABILITYIdempotency Receipt Ledger
Make execute, skip, retry and conflict decisions durable before a webhook, API or automation performs an external side effect.
Read case study →How I approach client systems.
Build the narrow path
Make one real workflow or artifact work end to end before expanding scope or adding convenience layers.
Turn bugs into tests
When an edge case matters, encode it as regression coverage so the fix survives the next refactor.
Need the same thinking applied to your system?
AI Workflow Reliability Audit
Failure-mode map, duplicate/retry-risk review, prioritized remediation plan and test checklist for one workflow.
Book direct ↗ Buy on Upwork ↗JSON / CSV Data Quality Guard
One data-flow audit with a validator or drift-check setup and a machine + human-readable report.
Book direct ↗ Buy on Upwork ↗Prompt & Content System
Ten reusable prompts with explicit input/output contracts, quality checklist, usage notes and examples.
Book direct ↗ Buy on Upwork ↗API & Webhook Contract Gate Setup
For one JSON API or webhook path that needs explicit validation before production or CI.
- required fields, types and enum rules
- reusable Python validator
- pass/fail exit semantics and QA report
- sanitized fixtures and handoff notes
Idempotency & Duplicate Prevention Setup
Harden one retry-sensitive webhook, API, AI-agent or automation path with durable execute/skip/conflict receipts and explicit retry handling.
Book direct ↗ Buy on Upwork ↗Direct checkout is for direct clients. If contact originated on Upwork or another marketplace, contracting and payment remain on that marketplace.
Bring the failing payload, not a perfect brief.
A broken example, screenshot, CSV, endpoint response or short written description is enough to begin scoping the problem.