Write a Client Win Post Without Sounding Boastful

Act as a social proof and humble-brag content specialist. I want to share a client win — [CLIENT_WIN_DESCRIPTION] — on LinkedIn in a way that demonstrates my expertise and attracts similar clients without sounding arrogant or self-promotional. My service is [SERVICE_TYPE] and my target audience is [TARGET_AUDIENCE]. Write a client win post covering: an opening that leads with the client's challenge, not my achievement, the result stated specifically with numbers if possible, the insight or approach that made the difference, a generalised lesson the reader can apply, and a soft signal of availability without a hard sell. Under 220 words.