CSV
Archiving Processed CSV Files Automatically After Import
Move each CSV out of the inbox only after its load commits, compress and verify it into dated folders, and expire old files with a clear retention rule.
7 min read
Library
Everything you need to level up your coding skills.
CSV
Building Idempotent CSV Imports That Are Safe to Run Twice
Four ways to make a CSV import safe to rerun, tested on one three-row file run twice: upsert on a key, row hash, replace by batch and a content-hash ledger.
7 min read
CSV
Loading a CSV From S3 Into a Database Without a Local Copy
Four ways to load a CSV stored in S3 into a database: a streamed pipe, the RDS aws_s3 extension, DuckDB reading s3:// directly, and a download-then-load job.
7 min read
CSV
A Python Script That Loads a Daily CSV Into PostgreSQL
A complete psycopg 3 script that stages a daily CSV with COPY, merges it with an upsert, records a content hash, and is safe to run again after a failure.
8 min read
CSVGuide
Automating CSV Imports Into a Database Without Surprises
Build a CSV import job that runs unattended: idempotent loads, one transaction, reject files, an archive, a ledger, locking, alerts and a safe backfill.
21 min read
CSV
Detecting Encoded Payloads Hidden in CSV Fields Fast
A short Python scanner that flags base64 blobs, percent-encoded text, script tags, formula starts and oversized fields in a CSV before you import it.
6 min read
CSV
Sending a CSV by Email Safely and the Better Options
Email is a poor way to move a CSV of real data. Ranked alternatives, from not sending it to expiring links, plus how to encrypt a file you must attach.
6 min read
CSV
Handling CSV Files Full of Customer Data Under GDPR
The GDPR duties that land on a CSV of customer data, from minimization and retention to access requests and deletion, turned into practical engineering steps.
7 min read
CSV
Limiting File Size and Row Count for CSV Uploads Safely
Pick CSV upload limits from measured parse and load speed, enforce each where it is cheapest, and reject bad shapes with a script that names the line.
7 min read
JSONGuide
JSON Security Mistakes in Apps and Pipelines and Their Fixes
A tested guide to JSON security: where bodies turn hostile, parser differences, prototype pollution, SQL, limits, numbers, logs, and a checklist.
18 min read
CSV
Hashing or Masking Columns in a CSV Safely Without Leaks
A plain SHA-256 of an email is reversible with a guess list. Use a keyed HMAC for tokens and partial masking for display, with a script that does both.
7 min read
Excel
Exporting Invoices to Excel With Totals That Add Up
Export invoices and lines to Excel so totals add up: one row per line, tax by a stated rule, document totals checked, no gaps in numbering and exact decimals.
7 min read
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