Alternatives to if

• In advanced system design discussions, we often need to express conditions without using standard if-clauses. Words like otherwise, supposing, and but for help us vary our professional register.
• Conjunction
• Function
• Example
• otherwise / or else
• States the negative consequence
• We must shard the database; otherwise, the cluster will crash.
• assuming (that)
• Presents a condition taken as true
• Assuming that the cache hit rate remains high, AWS costs will drop.
• but for / if it hadn't been for
• Expresses a counterfactual exception
• But for the new connection pool, the server would have failed.
• Remember
• Use otherwise and or else after an imperative or a statement to show what happens if the condition fails.
• Use assuming (that) or supposing when setting up a hypothetical premise in architectural reviews.
• Use but for and if it weren't / hadn't been for with noun phrases to highlight a crucial factor.
• Examples
• We need horizontal scaling; otherwise, Seattle users will experience high latency.
• Assuming that traffic surges in Boston, we will enable rate limiting.
• If it hadn't been for the caching layer, the London deployment would have crashed.
• Common mistakes
• Unless we scale out, or else the system will fail.
• We must scale out, or else the system will fail.

Complete the sentences

• We must add a read replica in Chicago; (otherwise) ____ the primary database will saturate.
• ___ (assuming) ____ that the traffic surge hits London, we should scale out.
• ___ (but for) ____ the new connection pool, Seattle servers would have dropped requests.
• Enable rate limiting now, (or else) ____ the thundering herd will crash the service.
• ___ (supposing) ____ that the cache invalidation fails in Boston, what is our fallback plan?
• ___ (if it hadn't been for) ____ the quick load shedding, the Austin cluster would have gone down.

Sources: photo by Polina Tankilevitch on Pexels