How-To
Step-by-step implementation guides.
21 posts
Feature Flags in Python, Done Right - A 2026 Tutorial for Flask and Django
A hands-on guide to implementing feature flags in Python, from a hand-rolled dict toggle to production SDKs in Flask and Django. Real illustrative code and honest trade-offs.
How to Calculate Sample Size for A/B Testing (2026 Guide)
Sample size decides whether your A/B test can find a real effect. Here is the formula, a worked example, the four levers that move it, and why halving your MDE quadruples the traffic you need.
How to Choose Metrics for A/B Testing - Primary, Secondary and the OEC (2026)
Most failed A/B tests fail at metric selection, not analysis. This guide shows how to pick one primary metric, structure secondary and guardrail metrics, avoid vanity metrics, and build an Overall Evaluation Criterion you can trust.
How to Design an A/B Test in 2026 - A Complete Framework
A trustworthy A/B test is won at the design stage, before a single user is bucketed. This framework walks the full design workflow - hypothesis, primary metric, guardrails, MDE, sample size, duration and analysis plan.
Feature Flag Management - A Practical Guide for 2026
Feature flags are easy to add and hard to manage. Here's how to name, own, roll out, and retire flags so they stay an asset instead of turning into technical debt.
Feature Flags Best Practices in 2026 - The 8 Rules That Prevent Flag Debt
The practices that separate teams who love feature flags from teams who drown in them - naming, short-lived flags, staged rollouts, kill switches, access control and cleanup.
Feature Flags in Go, Done Right - A 2026 Tutorial With Real SDK Code
A practical guide to implementing feature flags in Go, from a hand-rolled toggle to four production SDKs. Real code, honest trade-offs, and how to pick a platform.
Feature Flags in Java and Spring, Done Right - A 2026 Tutorial
How to implement feature flags in Java and Spring Boot, from a config property to four production SDKs. Real code, Spring integration, and how to choose a platform.
Feature Flags vs Config Files - When to Use Which (2026)
Config files and feature flags both control behavior without a code change, but they solve different problems. Here's how to tell them apart, and when a flag service beats a config file.
How to Choose a Feature Flag Tool in 2026 - A Buyer's Decision Guide
A practical framework for choosing a feature flag tool, from the four questions that actually decide it to the billing traps that surprise teams at renewal.
How to Clean Up Feature Flags in 2026 - Kill Flag Debt Before It Kills You
A practical guide to removing stale feature flags safely, from finding dead flags to a repeatable cleanup process, so flag debt never buries your codebase.
How to Do a Canary Release in 2026 - A Practical Step-by-Step Guide
A canary release ships a change to a small slice of traffic first, watches the metrics, then expands or rolls back. Here's the actual process, the guardrails that make it safe, and the tools that automate it.
How to Do A/B Testing in 2026 - A Practical Guide That Won't Lie to You
A hands-on A/B testing guide - hypothesis, metrics, sample size, randomization and the statistics that stop you shipping false wins - with the tools that fit each stage.
How to Implement Feature Flags in 2026 - A Practical Step-by-Step Guide
A hands-on guide to implementing feature flags without building flag debt - from your first toggle to targeting, rollout and cleanup, with the tools that fit each stage.
How to Migrate Off LaunchDarkly - A Step-by-Step Guide (2026)
Migrating off LaunchDarkly is mostly a matter of swapping SDKs and moving flag definitions. Here's the practical sequence, the traps to avoid, and where to land depending on why you're leaving.
How to Reduce LaunchDarkly Costs in 2026 - A Practical Playbook
LaunchDarkly bills on your highest-volume context kind plus service connections, so the bill grows quietly. Here is how to cut it without leaving, and when leaving is the cheaper answer.
How to Run an A/B Test in 2026 - A Step-by-Step Practical Guide
A hands-on guide to running an A/B test that gives you a trustworthy answer, from hypothesis to sample size to calling the result, with the tools that fit each stage.
How to Set Up Feature Flags in Next.js - A Practical 2026 Guide
A hands-on guide to adding feature flags to a Next.js app, from your first server-side toggle to edge evaluation and safe rollouts, with the tools that fit the App Router.
How to Use Feature Flags in React (2026) - The Pattern, the Gotchas, the Tools
A practical guide to wiring feature flags into a React app - the provider pattern, reading a flag with a hook, targeting users, avoiding the UI flash, and cleaning up stale flags - plus which tool fits.
Progressive Delivery - A Practical Guide for 2026
Progressive delivery means shipping a change to 1% of users before 100%, and rolling back on a bad metric automatically. Here's how to do it, and which tools measure and roll back for you.
Trunk-Based Development - A Practical Guide With Feature Flags (2026)
Trunk-based development only works if you can ship unfinished code safely. Here's how to do it with feature flags, step by step, and which tools fit each team size.