Isaac Bernat
Senior Backend Engineer at Preply
Barcelona, Catalonia, Spain
Summary
👤
Senior🎓
Top SchoolIsaac Bernat is a Senior Backend Engineer based in Barcelona with 11 years of experience building data-driven, revenue-impacting systems. He led design and scaling of Preply’s subscription platform, driving a 40% YoY lift in LTV and growing subscription GMV to 70% within a year, while owning long-running A/B experiments and cohort testing infrastructure. Comfortable across backend and fullstack roles, he has shipped high-traffic features—from GraphQL migrations and realtime dashboards to group-lesson orchestration and complex subscription policies. Earlier roles span data engineering, recommender systems, and CTO-level financial and ERP optimizations, reflecting both technical depth and business acumen. Isaac combines hands-on coding and repo stewardship with hiring and on-call leadership, and is skilled at turning product hypotheses into measurable growth. An engineer who balances rigorous academic training with pragmatic product outcomes, he often builds bespoke tooling to enable analytics and experimentation at scale.
11 years of coding experience
10 years of employment as a software developer
M.Sc. Informatics Engineering, Computer Engineering, M.Sc. Informatics Engineering, Computer Engineering at Universitat Politècnica de Catalunya (BarcelonaTech, UPC)Norwegian University of Science and Technology
Catalan, Spanish, English, Swedish
Stackoverflow
385reputation
13kreached
5answers
9questions
Github Skills (109)
python10
closed10
javascript10
youtube10
ttml10
js10
srt10
netflix10
youtube-dl10
ffmpeg10
webvtt10
subtitle10
vtt10
regex10
xml10
Programming languages (11)
Github contributions (5)
isaacbernat/presentations
Dec 2018 - Jan 2023
10^18x Code optimisation, Prisoner's Dilemma, Handling TODOs and Rhythm notation
Contributions:155 commits, 29 PRs, 199 pushes in 4 years 1 month
optimization-algorithmstodosdilemmahandlingpython3
isaacbernat/netflix-to-srt
Jan 2017 - Jan 2022
Rip, extract and convert subtitles to .srt closed captions from .xml/dfxp/ttml and .vtt/WebVTT (e.g. Netflix, YouTube)
Contributions:11 reviews, 67 commits, 54 PRs in 5 years 1 month
pythonyoutubesubripvideocaptions
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