Engineering Blog

Technical deep dives on building developer tools, API design, and shipping products. From the team behind Anethoth.

How to Build a PDF Invoice API in Python (Under 200 Lines)

A step-by-step guide to building a production-ready PDF invoice generation API using Python, FastAPI, and WeasyPrint. Complete with templates, validation, and Stripe billing.

2026-04-16 12 min read PythonFastAPIPDF

The Complete Guide to Cron Job Monitoring in 2026

Why your cron jobs fail silently, how dead man's switch monitoring works, and how to set up reliable alerting for every scheduled task in your infrastructure.

2026-04-16 10 min read DevOpsCronMonitoring

Feature Flags Best Practices for Small Teams (2026 Guide)

How to implement feature flags without LaunchDarkly's price tag. Practical patterns for progressive rollouts, A/B testing, and kill switches that every startup should use.

2026-04-16 11 min read Feature FlagsDevOpsDeployment

Webhook Debugging: A Developer's Complete Guide

Everything you need to know about debugging webhook integrations — from capturing payloads to replaying failed deliveries. Covers Stripe, GitHub, Shopify, and more.

2026-04-16 9 min read WebhooksDebuggingAPI

How to Automate Invoice Generation in Your SaaS (2026)

Stop manually creating invoices. Learn how to automate PDF invoice generation with an API — from Stripe payment events to sending professional invoices automatically.

2026-04-16 10 min read SaaSInvoicingAutomation

7 Crontab Mistakes That Break Production (And How to Fix Them)

Common crontab pitfalls that cause silent failures in production — from timezone confusion to overlapping jobs. Practical fixes for every mistake.

2026-04-16 8 min read CronLinuxDevOps

Progressive Rollout Strategy: Ship Features Without Breaking Production

How to use feature flags for canary deployments, percentage rollouts, and targeted releases. A practical guide to shipping confidently with real-world examples.

2026-04-16 11 min read Feature FlagsDeploymentCI/CD

Stripe Webhook Integration: The Complete 2026 Guide

Everything you need to handle Stripe webhooks correctly — signature verification, event types, idempotency, error handling, and testing with real payloads.

2026-04-16 13 min read StripeWebhooksPayments

Free HTML to PDF API: Convert Any Webpage to PDF with One Request

A free, no-signup HTML to PDF conversion API. Send HTML, get a PDF back. Supports custom page sizes, CSS styling, and Markdown input. Built for developers who need quick document generation.

2026-04-19 8 min read PDFAPIHTML

Free Cron Expression Parser API: Describe, Validate, and Calculate Next Runs

A free REST API that parses cron expressions into human-readable descriptions, validates syntax, and calculates upcoming execution times. No signup required — just send a GET request.

2026-04-19 7 min read CronAPIDevOps

Free Webhook Testing API: Echo, Inspect, and Debug HTTP Requests Instantly

A free HTTP echo API that mirrors any request back as JSON — method, headers, body, IP. Debug webhooks, test HTTP clients, and inspect headers without installing anything.

2026-04-19 7 min read WebhooksHTTPDebugging

Free Feature Flag Playground API: Test Rollout Rules Without an Account

A free API to evaluate feature flag targeting rules, simulate percentage rollouts across users, and test consistent hashing bucketing. No signup — experiment with feature flags instantly.

2026-04-19 8 min read Feature FlagsAPIRollouts

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