Leah Thompson

bufio.Scanner is great until it isn’t: by default it refuses tokens larger than 64K, which makes it a bad fit for long log lines or large JSON records. The failure mode is subtle—scan stops and Err() returns a token-too-long error. For production log

CSV imports are where memory usage quietly explodes if you read everything at once. I stream rows with encoding/csv, validate each record, and batch inserts to keep DB overhead low. The important detail is backpressure: if the database is slow, the im

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,

For gRPC services, GracefulStop is ideal because it allows in-flight RPCs to finish, but it can hang if handlers ignore cancellation or if clients never close streams. I wrap shutdown in a deadline: call GracefulStop in a goroutine, and if it doesn’t

For internal service-to-service calls, mutual TLS is a pragmatic way to get strong identity without bespoke auth headers. The main pitfalls are certificate rotation and trust configuration. I build a x509.CertPool from a dedicated internal CA, load a

For transactional email, the reliability problem is usually latency and retries, not MIME formatting. I prefer an HTTP email provider because requests are easy to bound with context.WithTimeout and easier to observe than raw SMTP. The code below build

YAML configuration is convenient, but it’s also a footgun when typos silently get ignored. I enable KnownFields(true) so unknown keys cause an error, which turns “silent misconfig” into a fast failure. That is especially useful during refactors when f

Even in API-heavy systems, I occasionally render HTML emails or a lightweight admin page. I always use html/template (not text/template) so content is escaped by default, which prevents accidental XSS when variables contain user input. I also keep tem

Scheduled jobs get risky when deploys overlap or when jobs take longer than their interval. I use robfig/cron with a wrapper that creates a per-run context.WithTimeout, adds a bit of jitter to avoid synchronized load across instances, and logs start/f

I don’t try to re-implement full JSON Schema in Go, but I do like returning validation errors that are easy for clients to render. The pattern is: decode into a struct, validate required fields and invariants, and return a slice of {field, message} is

I like config that fails loudly when it’s wrong. The helpers below parse environment variables with explicit defaults and good error messages, which prevents subtle “zero value” behavior in production. This is especially important for flags like ENABL

Rate limits are normal in production; what matters is how clients behave when they hit them. Instead of hammering an upstream with immediate retries, I parse Retry-After (seconds) and sleep before retrying. I still keep an upper bound so one request d