See https://www.elbeno.com/blog/?p=1795 (or https://crosshare.org/crosswords/aZ0lpCTDSztWEsvvuboa/cppcon-2025) if you want to try it. If you’re here for solutions, read on. Definitions are given in italics. My personal likes are 4D and 13D.
1A BABBAGE
Supergroup among leaders to back grant endowment for computing pioneer (7)
ABBA (“supergroup”) inserted into (“among”) BGE (“leaders to Back Grant Endowment”)
5A MAD RUSH
Headlong dash for Spooner’s marvellous porridge (3,4)
“Marvellous porridge” = RAD MUSH
9A CASKS
Barrels of (a hundred) requests (5)
C (“a hundred”) + ASKS (“requests”)
10A & 21A LIGHTNING TALK
Wasted all night knitting, not in time to give quick speech (9,4)
Anagram (“wasted”) of (ALL NIGHT KNITG)* — “all night knitting” without IN and T (“not in time”)
11A TICKER TAPE
Band with heart going first in parade? (6,4)
TAPE (“band”) preceded by (“going first”) TICKER (“heart”)
12A STAT
A single 6, quickly! (4)
DD. A single piece of DATA (6D) or abbreviation for statim
14A EAR FOR MUSIC
Artistic skill cures AI hallucination about class (3,3,5)
Anagram (“hallucination”) of CURES AI around FORM (“class”)
18A SEAL THE DEAL
Apply varnish with shaking hands? (4,3,4)
DD/CD. (DEAL = pine wood)
22A REFLECTION
Consideration of percentile spread without price-to-earnings (10)
Anagram (“spread”) of OF RCENTILE (“of percentile” minus PE “Price-to-Earnings”)
25A PROTECTED
How a class, or members of one, may be guarded (9)
DD/CD. https://en.wikipedia.org/wiki/Protected_group and https://en.cppreference.com/w/cpp/language/access.html
26A BYTES
Data? I buy it less, with holes in (5)
Alternate letters (“with holes in”) of I BuY iT lEsS
27A SUSPEND
Initially on board, flip and postpone (7)
UPEND (“flip”) with it’s initial letter placed inside SS (“on board”)
28A V-NECKED
Against Calvin Klein, restricted by need of clothing line (1-6)
V (“against”) + CK (“Calvin Klein”) inside (“restricted by”) NEED
1D & 2D BACK TO BASICS
Track S? (4,2,6)
CD. S is the “back (letter) to” BASICS. https://cppcon.org/b2b/
3D AISLE SEATS
Sat, confused about key main points, in the audience (5,5)
Anagram (“confused”) of SAT around ISLE (“key”) + SEA (“main”)
4D E-FLAT
Key, in leadership positions, to find loophole anywhere in terms of non-compete agreement (1-4)
FLA (leadership positions to Find Loophole Anywhere) inside ET (terms — last letters — of non-competE agreemenT)
5D MEGAPHONE
Poor PA system is huge local joke (9)
MEGA (“huge”) + PH (“local” – Public House) + ONE (“joke”)
6D DATA
A bit flipped in input (4)
Reversal (“flipped”) of A TAD (“bit”)
7D UNIT TEST
Could be nuttiest way to ensure quality (4,4)
Anagram (“could be”) of NUTTIEST
8D HIGH-TECH
Sophisticated but stoned? Train with no advantage (4-4)
HIGH (“stoned”) + TE(a)CH (“train with no advantage”)
13D IMPLACABLE
Like the terminator of a limp, frayed wire (10)
Anagram (“frayed”) of ALIMP + CABLE (“wire”)
15D REELECTED
After dance, city detective back in office again (9)
REEL (“dance”) + EC (“city“) + TED (reversal — “back” — of “DETective”)
16D ISOTOPES
I call for help! Drink contained hydrogen and deuterium (8)
I + SOS (“call for help”) with TOPE (“drink”) contained within
17D BALLOONS
Party followed by two rounds necessitates emptying bladders (8)
BALL (“party”) + OO (“two rounds”) + NS (“necessitates emptying”)
19D TIKTOK
Horologists’ network? (6)
(Not very) CD.
20D UNUSED
New education puts posh students first (6)
ED (“education”) with U (“posh“) + NUS (“students“) preceding
23D LCD TV
Panel shows regularly elucidate vi (3,2)
Alternate letters (“regularly”) of eLuCiDaTe Vi
24D MERE
Engineers cycle around lake (4)
REME (“engineers“) rotated (“cycle”) and reversed (“around”) — although the reversal is kind of optional