About
Kyriakos Eleftheriou is the Founder and CEO of Terra API.
Served as Sergeant Major in the Special Forces - Mountain Commando of the Cyprus National Guard.
The first ever Greek-Cypriot founder backed by Y Combinator.
Forbes 30 under 30 (Technology).
BEng and MSc Electrical Engineering, MSc Management from Imperial College London, graduating top of his class.
Research
It Takes Four Days to Recover From a Night Shift
September 1, 2026
Menopause Shows Up in Your HRV Before It Shows Up on the Calendar
August 25, 2026
Terra Smart Fill: Solving Missing Health Data
August 18, 2026
What Winning the World Cup Does to Your Health
July 23, 2026
Stacking Sauna and Cold Plunge, or?
June 23, 2026
The World Cup Hosts Don't Play Much Football
June 16, 2026
Your Evening Workout Is Costing You Sleep
May 19, 2026
What Actually Makes Us Dream?
May 12, 2026
Tube Strikes Made Londoners Active
April 24, 2026
Cold Plunging Might Make Your Biomarkers Worse
April 14, 2026
Blog
Alternatives to the latest changes in the Strava API
November 19, 2024
Introducing Health Scores for developers
June 19, 2024
See you at HackHarvard, hackers
October 18, 2023
TerraAPI at HackMIT
September 25, 2023
Startup Spotlight: Driftline
January 12, 2023
Startup Spotlight: Kalibra
December 14, 2022
Start-up Spotlight: Shyro Health
November 14, 2022
Team Spotlight: Introducing Ross
November 11, 2022
Start-Up Spotlight: Tastermonial
November 4, 2022
Buy or build: Should you build integrations in house, or use Terra’s API
November 1, 2022
Podcast
Vinod Khosla: “It’s Over for Human Doctors”
August 21, 2026
Hims & Hers CTO: Mo Elshenawy
August 6, 2026
George Hadjivarnava: Founding Foody, and building AI at Terra
July 3, 2026
Early to Every Wave - Former Y Combinator President | Geoff Ralston
June 1, 2026
Head of Samsung Next: David Lee
May 1, 2026
HYROX CGO: Douglas Gremmen
April 8, 2026
CTO + Director of AI at Flo Health: Roman Bugaev + Vladislav Nedosekin
March 2, 2026
Glovo and Yellow.vc Co-Founder: Sacha Michaud
January 18, 2026
Thriva CTO: Tom Livesey
October 21, 2025
Huma CEO: Dan Vahdat
September 21, 2025
