IT Prefixes

re- = "again" or "back to a previous state"

• refactor — restructure existing code without changing its external behaviour (do the structuring again, better)
• redeploy — deploy again (often after a fix)
• revert — go back to a previous state ("revert the commit", "revert to version 2.1")
• rollback — back to a previous working version (rollback is roll + back, but functionally similar)
• replay — replay events (event sourcing)
• retry — try again (retry logic, retry with exponential backoff)

Note: "refactor" is not "re-factor" in standard use — it is one word. The prefix meaning is embedded but the word functions as a single unit.

de- = remove or reverse — "decouple" means reduce or remove tight coupling between components. The prefix de- appears in many IT terms:

• decouple — make components independent ("decouple the UI from the data layer")
• deprecate — de + precate (from Latin praecari, to pray for) — formally mark as obsolete
• debug — de + bug — remove bugs
• deserialise — de + serialise — convert from a serialised format back to an object
• deallocate — de + allocate — free allocated memory
• decompress — de + compress — reverse compression

Tight coupling = changing one component requires changing others. Decoupling = components can evolve independently, which improves maintainability.

micro- = small, fine-grained, single-purpose

• microservice — a small, independently deployable component of a larger application, each with a single bounded responsibility ("the payments microservice", "the notifications microservice")
• microbenchmark — a benchmark for a tiny, isolated piece of code (as opposed to benchmarking the whole system)
• microcontroller — a compact processor with integrated memory and I/O, used in embedded systems
• micro-optimisation — optimising a very small piece of code, often at the cost of overall readability

Contrast with "monolith" (single deployable unit) and "macro" (large-scale). Note: "micro-optimisation" is sometimes used pejoratively — optimising tiny pieces while ignoring the bigger architectural bottleneck.

over- = more than necessary, excessive

• overengineer — design a system more complex or generalisable than the current problem requires ("don't overengineer this; we just need a simple script")
• overload — load more than capacity; also: method overloading in OOP (defining a function multiple times with different signatures)
• overwrite — write over existing data
• override — in OOP, providing a new implementation of a parent class method in a subclass
• overfitting — in ML, a model fitting training data too closely and failing to generalise

Contrast with under-:
• underprovisioned — not enough resources allocated
• underfitting — a model too simple to capture patterns in the data

pre- = before, in advance

• prefetch — retrieve data before it is explicitly requested, anticipating future need ("the browser prefetches the next page")
• preload — load a resource before it is needed ("preload the hero image via ")
• preprocess — process input before the main operation ("preprocess the CSV before importing")
• provision → pre-provision — set up infrastructure before it is needed
• staging environment is sometimes called a "pre-production" environment
• precondition — a condition that must be true before a function runs

Contrast with post-:
• post-deployment — after deployment
• post-mortem — after the incident (note: written as "postmortem" without hyphen in most tech contexts)

Option B — "unreachable" — the un- prefix combined with a past participle or adjective forms a valid negative: "unreachable code" is a standard software term for dead code that can never be executed.

Common un- words in IT:
• unreachable — cannot be reached (unreachable code, unreachable host)
• unhandled — not handled (unhandled exception)
• unresolved — not resolved (unresolved dependency, unresolved conflict)
• untested — not tested (untested code path)
• unmaintainable — cannot be maintained

Why the others are wrong:
• "undeploying" — the correct form is "rolling back" or "undeploy" is not standard; you "shut down" or "roll back" a deployment
• "unscaled" — not standard; use "scaled down" to reduce capacity
• "unfetch" — not a word in any context