NumWise
Accounting SaaS with format-agnostic bank-statement import (CSV, XLSX, OFX, QIF, MT940, CAMT.053 from any bank or country), AI-assisted column mapping, and 113 shipped features - live at numwise.eu.
// delivery facts
113
Features shipped
Budgets, categories, multi-account consolidation, import pipeline
6
Parser formats
CSV, XLSX, OFX, QIF, MT940, CAMT.053 - any bank, any country
168+
Parser tests
Production-grade coverage; real bank exports used as fixtures
103 KB
Bundle savings
Initial bundle after lazy-loading parser modules (was 1 MB)
The challenge
Accounting tools forced users to export from their specific bank in a specific format, then re-import manually - a process that breaks immediately when switching banks, countries, or software versions.
- 1
Every bank exports in a slightly different column layout even within the same nominal format (e.g. CSV)
- 2
Proprietary formats like MT940 and CAMT.053 required specialist parsing libraries that most tools did not support
- 3
Column-mapping was a manual, error-prone step that users had to redo every time they imported a new file
- 4
Multi-account households had no consolidated view - each account lived in a separate import silo
How it was built
Format-agnostic parser registry with six adapters (CSV, XLSX, OFX, QIF, MT940, CAMT.053) plus a Claude API column-mapping layer for unknown layouts, unified into a single NormalizedRow pipeline.
Parser registry pattern: each adapter is self-describing and emits a typed NormalizedRow - the downstream pipeline is format-agnostic by design
Claude API column-mapping layer activates only when the parser detects an unknown column layout; it resolves ambiguous headers and stores the learned mapping for reuse - no repeated prompting
MT940 and CAMT.053 parsers ported from a production meocc codebase with 168+ tests - verified against real bank exports from PKO, Pekao, ING, and Revolut
Lazy-loaded parser modules reduce initial bundle by approximately 10x (from 1 MB to 103 KB) - heavy parsing logic only loads when the user triggers an import
Multi-account consolidation aggregates transactions across any number of linked accounts into a single ledger view with budget tracking and category assignment
What shipped
Production accounting SaaS live at numwise.eu - 113 features shipped, 6-format parser with 168+ tests, and AI-assisted column mapping for unknown bank layouts.
// full stack
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