Nginx · The edge of your stack
What are location blocks and which modifiers exist?
Short answer
A location block matches a URI and applies directives to it. Modifiers select exact, prefix, preferential prefix, case-sensitive regex or case-insensitive regex matching, plus named locations.
Locations are how Nginx routes requests internally. A prefix location matches the start of a normalized URI; a regex location applies a pattern. The modifier changes both syntax and precedence, so choosing the right one is essential.
location = /health {
return 200 "ok";
}
location ^~ /static/ {
root /var/www;
}
location ~* \.(jpg|png|css|js)$ {
expires 30d;
}
location /api/ {
proxy_pass http://backend;
}
location @fallback {
proxy_pass http://backend;
}Modifiers
- No modifier is a prefix match; the longest matching prefix is remembered
- = requires an exact URI match
- ^~ is a prefix match that stops regex evaluation if it wins
- ~ is a case-sensitive regex; ~* is case-insensitive
- @ names a location for internal redirects, error_page or try_files
Follow-ups you should expect
Interviewers use these to check whether the first answer was understanding or memorisation.
- 1When should you use = instead of a prefix match?
- 2What does ^~ change compared with a normal prefix location?
- 3How does a named location get invoked?
- 4Can location blocks be nested?
Say it in the interview
A location block maps a URI to behavior. The modifier is the important part: an exact match with =, a longest prefix match with no modifier, a prefix that blocks regex evaluation with ^~, and regex matching with ~ or ~*. Named locations are internal targets for try_files or error_page. I choose the most specific modifier I need and avoid broad regexes that accidentally capture API or asset traffic.
Use this as a model, not a script. Saying it in your own words is what makes it survive follow-up pressure.
Related questions
Reading is step one
Now say it out loud.
Understanding an answer and delivering it under pressure are different skills. Rehearse this topic in a live Nginx mock interview and get scored feedback on depth, clarity and confidence.