A production engineering reference for the teams that build reconciliation pipelines.
Bank-feed ingestion · transaction matching · exception routing · audit-grade financial controls.

🌐 Read it live → www.financialreconciliation.com

Automated Financial Reconciliation & Ledger Matching is a deep, practitioner-focused engineering reference for FinOps engineers, accounting-technology developers, fintech builders, and Python automation teams — the people who treat reconciliation as a deterministic state machine rather than a back-office chore.

Every page is written the way engineers actually read documentation: problem framing → architecture → production code → configuration → failure modes → audit and compliance. The code is real, typed, and runnable — built on the pydantic / rapidfuzz / asyncio / Decimal stack — and every worked example threads a structured audit trail (trace_id, source_hash, match_decision) through the pipeline so the result can be reconstructed for a regulator.

The reference is organised into four in-depth areas:

• Core Architecture & Bank Feed Ingestion — deterministic, idempotent ingestion of OFX, MT940, ISO 20022 (camt.053) and modern API feeds, normalised into a single canonical transaction model.
• Transaction Matching Algorithms & Logic — exact and reference-key matching, fuzzy string similarity (Levenshtein, Jaro-Winkler, token-set ratio), date-window and amount-tolerance rules, and multi-step 1:1 / 1:N resolution chains.
• Exception Routing & Human-in-the-Loop Workflows — deterministic routing, async approval queues with backpressure, SLA-gated escalation, batch approval interfaces, and dead-letter remediation.
• Compliance, Audit Trails & Financial Controls — immutable append-only hash-chained ledgers, SOX 404 evidence packaging, and CI/CD gating for financial-control changes.

• Runnable, typed Python — Python 3.10+ with strict type hints, Decimal money, timezone-aware UTC, and audit logging on every decision path.
• Original diagrams — every architecture, data-flow, and state-machine diagram is hand-authored inline SVG that adapts to light and dark themes.
• Audit-grade by default — SOX 404, PCI-DSS, GAAP/IFRS and ISO 20022 considerations are treated as first-class outputs, not afterthoughts.
• Grounded in real trade-offs — thresholds, tolerance bands, concurrency limits and failure codes come with defaults, ranges, and tuning guidance you can lift straight into a codebase.

This repository contains the full source of the site. It is a static site built with Eleventy (11ty) and deployed on Cloudflare Pages.

npm install      # install dependencies
npm run serve    # local dev server at http://localhost:8080
npm run build    # production build into ./_site

Content lives as Markdown under content/; templates, styles, and assets live under src/.

👉 www.financialreconciliation.com

Maintained by financialreconciliation.