Senior Backend/Data Platform Engineer: Independent Code Review and Ongoing Audits

We are looking for an experienced engineer to independently review a private backend codebase and give ongoing assessments of its engineering quality. The engagement covers backend and data-platform engineering only. Python and PostgreSQL experience is required. Company, product and further technical details will be shared under a mutual non-disclosure agreement (MNDA). Our two goals - See how proposed changes affect dependent components before they are built, to prevent unexpected breakages. - Keep engineering standards high through regular reviews of correctness, architecture, security and maintainability. How the engagement works 1. Paid trial: review a small, agreed component boundary, its requirements and its tests, then walk us through your findings. Propose your approach, time and price. 2. Paid scoping (selected engineer only): agree the repositories and versions covered, the critical workflows, the test environment, the deliverables and the exclusions. 3. Initial deep review, covering; - Data correctness: validation, completeness, duplicates, retries and partial failures. - Architecture and code quality: responsibilities, modularity, complexity, error handling and maintainability. - Change impact: assess whether impact analysis covers the affected components and tests, and identify omissions or unverified dependencies. - Automated safeguards: whether checks enforce the intended requirements, and where they could miss failures. - Tests and CI: whether tests catch representative defects, and whether failed or missing required checks block merging. - Database security: effective permissions, application roles and data isolation, including tests of denied access. - Operational reliability: migrations, observability, recovery and performance risks. 4. Fortnightly reviews: recent critical pull requests, check results, previous fixes, or one priority risk. Significant changes may need an agreed review before merging. 5. Quarterly reviews: reassess the initial review areas across the wider backend codebase, comparing improvements, regressions, unresolved findings and priorities. Deliverables (evidence required) - Initial and quarterly reviews: an executive summary plus technical findings. - Fortnightly reviews: a short report. Each confirmed defect must include: - severity and practical impact; - the reviewed commit and code location; - expected versus actual behaviour; - reproduction steps or an executable demonstration; - a recommended fix and a regression check. Separate confirmed defects from unverified risks. State what you examined, what you couldn't verify, and what was out of scope. There is no minimum number of findings. Experience we need - Strong production Python, PostgreSQL and SQL. - Database roles and permissions. - Proving correctness against independently established expected results. - Retries, idempotency, schema evolution and dependencies between components. - Automated testing and CI (for example pytest and GitHub Actions). - Maintaining production systems as they grow. - Clear written English, explained for a non-technical founder. Judgment and production ownership matter more than titles. Working arrangements - Remote, with some overlap with UTC+2 working hours preferred. - An MNDA is required before any private details or code access. - Read-only access to repositories. Tests and deliberate faults run only in an agreed isolated environment. No production credentials are provided. - The named engineer must personally do and explain the review, and disclose any AI assistance used (preferably none). - Scope and pricing are agreed before each stage begins.