const defines compile-time constants, and const fn are functions that can run at compile time. I use const for magic numbers, lookup tables, and configuration that never changes. const fn is powerful for building complex constants (like hash maps or a

Production debugging is about logs that are searchable. Emit JSON with consistent keys (requestid, memberid, duration). Even if you later add Lograge, this structure maps cleanly.

Rate limiting is essential protection against abuse and ensures fair resource distribution across API consumers. Rack::Attack with Redis backing provides a robust, shared state solution that works across multiple application servers. I define differen

Hotwire doesn’t replace caching—it makes it more valuable because you’re sending HTML frequently. I use fragment caching inside list partials and keep cache keys stable with cache blocks. The pattern is: cache each row by record, and cache the list wr

Multi-tenancy serves multiple customers from one application. I implement tenant isolation via schemas, databases, or row-level security. Shared schema with tenant_id column is simplest—good indexing essential. Separate schemas per tenant improves iso

Config bugs are some of the most expensive production incidents because they vary by environment and can be hard to reproduce. I keep configuration in a typed struct, load it from environment variables, and validate it before the server starts. The va

Spinners hide layout shifts and make an app feel slow even when it isn’t. Skeletons preserve layout and give users a sense of progress without jumping content around. I keep skeleton components simple and match the shape of the final UI. One practical

Time parsing bugs are common in APIs: clients send different formats, empty strings, or timezone-less values. I like making time parsing explicit by wrapping time.Time and implementing UnmarshalJSON. The wrapper accepts RFC3339, treats null as “unset,

Rails migrations evolve database schema over time. I use change method for reversible migrations. Migrations create tables, add/remove columns, add indices. up and down methods provide explicit control. Irreversible migrations like data transformation

Sometimes you want to show non-blocking warnings (e.g., “link looks unreachable”) while still saving. Turbo streams can append warnings to a panel without rerendering the whole page.

Synthetic performance tests don’t always match what real users experience. Web Vitals reporting gives you field data (CLS, LCP, INP, etc.). I collect vitals on the client and POST them to a lightweight endpoint, then aggregate on the backend. Sampling

Not every part of a page needs to load immediately. For heavy panels (analytics charts, audit logs), I use a Turbo Frame with src and a tiny Stimulus controller that sets the src when the element becomes visible via IntersectionObserver. This avoids f