Jesús Leganés-Combarro

– Added support to Google libwebrtc library for audio samples timings optimal for satellite phone calls in Opus codec – Study lower limits on bandwidth usage of state-of-the-art video codecs in web browsers – Research on narrow bandwidth audio voice transmission using custom streaming protocol over UDP datagrams and Bluetooth BLE GATT messages down to 800bps – Improve support of Mediasoup for telehealth application – Audited code of streaming embedded devices and proposed new architecture to reduce real-time latency – Adapt Texas Instruments CC33XX BLE chipset to Linux 6.1 on BeagleBoard Black, Raspberry Pi 4B, i.MX8 M and i.MX92 embedded devices – Reduced 30-50% connection times and latency of media streaming server with 60k video sources, using 90% less memory, and done in 1/30 of initial estimated time – Identified electrical issues in IoT affecting to connectivity of local audio streaming architecture

– Teacher of legacy and modern web technologies – Linux terminal, Apache, Tomcat, nginx – Node.js, Express, Fastify, Python, Django, FastAPI – Docker, docker-compose

– Led technical architecture and engineering initiatives across multiple AI- and WebRTC-driven startups under a common technology group in the United Arab Emirates. Combined hands-on development with strategic leadership, ensuring delivery, scalability, and best engineering practices. – Directed development of real-time NLP pipelines for avatar agents with intent detection and ElevenLabs voice, achieving 20x lower latency (measured end-to-end) – Architected a scalable AI infrastructure with 99.99% uptime (SLO + monitoring) and managed a 6-engineer distributed team across backend, ML and voice domains. – Delivered 90+ PRs (8 in one week), accelerating roadmap execution and closing a major product epic. – Enhanced backend and CI/CD reliability (fixed OOM issues, flaky tests and Go vulnerabilities) earning commendations for technical leadership, expertise and commitment. – Optimized CI pipelines, and expanded unit and Playwright E2E test coverage by 40%, improving overall quality and stability. – Championed code audits, best practices and testing culture across Python (FastAPI) and Node.js (Next.js) projects, raising engineering standards group-wide. – Designed migration from VoiceFlow to LangFlow – Implemented from scratch a high-performance document classifier and LLM trainer without pre-trained models, handling 20 processes and 1000+ threads on a regular laptop, achieving +80% precision – Implemented generic and vertical-agnostic RAG

– Cervus III: Antidron system – CRBERUS: Anti-drones platform control module for detection, inhibition and elimination – Reduce video streaming latency from 30s to <500ms (end-to-end) – Identified performance and security issues – Design and develop modular and extensible architecture for web-based Operating System built on Django, with direct access to local and remote hardware resources and services (GPS, cameras, radar, RF, APIs...) – Improve maintainability, reliability and delivery times compared to legacy project written in PHP – Reduced deployment times 50% (wall time) – Appraised by superiors for simplifying and modularizing the system architecture, reducing development times and lowering the entry barrier to allow contributions of new functionality by interns – Implementation of PECAL 2210 specification (NATO software quality assurance requirements) – Detected and optimized latency and frame drop issues, increasing system stability 90% (out-of-time frames) – Proposed architecture improvements to reduce complexity, latency and server costs – Provided proof-of-concept demonstrating the impracticality of three proposed streaming security requirements. – Proposed alternative security models aligned with system constraints.

– Comera: International Calling and Messaging App – Analyzed pros and cons of different WebRTC network architectures for multiple participants video chat – Identified flaws on current P2P network architecture – Fix incompatibility encoding issues with low-cost devices – Analyze delays on signaling and initialization of calls on low bandwidth / narrowband networks – Wrote article about WebRTC connection errors and how to fix them – Define features of next generation messaging app, including performance, accessibility, bandwidth usage... – Integrate Lyra codec in libwebrtc – Code quality and performance audit – Replace ad-hoc chat mechanism for XMPP – Improve performance of access to multi-gigabytes files – Implementation of acceptance and integration tests – Implemented real-time collaborative editor, increasing user engagement by 30% week-over-week – Audited code quality and project performance – WebRTC audit for in-browser music concerts in 3D environment based on audio and video streaming – Designed new architecture optimized for scalability, with 15% reduction of server costs – Implemented acceptance and integration tests, increasing development speed 2x (wall time) – Consulting and research of integration of Alexa voice assistant

– Company raised $11.6M seed funds in April 2022, less than 2 years since its foundation – Acquired later by Cloudflare in 2025 – Audited project WebRTC architecture – Implement horizontal scalability solution on top of Mediasoup – Design deployment scheme for multi-platform Mediasoup prebuilds – Design & develop high performance fMP4 + LL-HLS server from scratch – Projects quality & best practices audit – Promote and improve engineering culture in the company members, specially regarding testing and CI/CD topics – Code quality and performance audit; isolation and modularity of code – Design of new architecture optimized in scalability and reduction of costs – Development of WebRTC signaling and application server optimized for connection establishment latency – Replaced socket.io with server-based WebRTC DataChannels as events propagation transport layer, simplifying architecture and reducing signaling measured latency 50%. – Build automated testing environment based on docker-compose instead of manual execution, increasing 3x development speed – Ported Node.js Mediasoup application to Rust, achieving ~50% performance improvement in Mediasoup element creation. – Designed new architecture for P2P streaming focused on privacy, with 90% reduction of combined server and network costs – Design engine of no-code tool to create backend servers described in JSON files

– CollaboVR: collaborative virtual reality environment – Hellios: decentralized social network – P2P-mediastream: HLS streaming over WebTorrent – FrameVR: Web-based VR collaborative environment – Audited code for WoW Room project, IE Business School in-house WebRTC online education videoconference platform – Designed new multi-device architecture (control from tablet, multiple cameras, several teachers per class...) focused on performance, scalability and maintenance. Improved 4x connection wall times and WebRTC performance – Optimized WebRTC based mobile and desktop videoconference web application powered by Kurento media server and Jitsi Meet – Contributed updates to kurento-utils APIs, adding missing features to node-webrtc and browser feature selection support – Integrated WebRTC video conference app as Microsoft Outlook add-in – Reverse engineering of third-party undocumented WebRTC signaling protocol – Stream POV videos from VR headsets to HLS – Designed architecture for Augmented Reality based wearable remote assistance and videoconference platform – Researched web technologies state-of-the-art and implement Proof-of-Concept using HTML5 and Media web standards – Development of P2P decentralized Android multi-videocall – Identify WebRTC issues on 4G networks – Study and implement Terraform development best practices – Create Github Actions in Python for repositories creation, maintenance and security policies – Implemented Braintree payment gateway – Audited code quality and performance of the system, and applied development best practices

– Development of chatbot backend server based on DialogFlow – Code audit – Review and mentoring of Node.js projects best practices to other team coworkers – Split monolith architecture to multi-server to increase maintainability and performance – Design and develop chatbot backend from scratch using Django – Design and develop company internal integrated development environment – Design, develop and administer automated Azure DevOps CI pipelines to improve errors detection and decrease releases lifecycles, and development of versioning tools – Move platform from AWS to Azure to reduce costs – Code quality audits for company backend and frontend projects

– Company acquired by iTalki – Design full stack refactor for 2.0 version of WebRTC social video chat mobile app (ReactNative mobile app, Node.js multi-server backend, XMPP as messenger and WebRTC signaling) – Reduce backend source code estimated technical debt from 4 years to 9 months – Add support to `node-canvas` library to render on Linux framebuffer on embedded devices with double buffering and vertical sync – Port Flutter engine to Linux terminal console adding platform support for EGL + GBM – Port and pack Open Source applications (mainly Rust and C/C++) to WebAssembly – Improvements on integration in Python environments – Implement automated CI/CD infrastructure – Evaluate candidates of selection process – Code performance audit

– Design architecture of unified communications timeline application – Development of Django web app for monitoring solar accumulators – Design and development of ReactNative application for web and mobile for workflows management – Development of Open Source library for real-time creation of ReactNative forms from JSON descriptions – Add web support for web platform and media capture on Android platform to ReactNative-document-picker library – Integration of voice assistant services – Node.js backend server for CMS platform – Design of one-way encrypted storage – Designed and implemented a one-way encrypted storage system – Praised by coworkers for my technical knowledge and skills – Promotion of Open Source usage, contributions and releases and spokesperson of the company in the Open Source communities. Made company the administrator of ReactNative Spain Meetup group – Optimized performance and bandwidth usage of React webapp up to 85% (Chrome Dev Inspector) – Design of Open Source transport-layer agnostic high performance Node.js streams-oriented file transfer protocol with support for auto-resume, parallel asymmetric transfers, usage of backend servers, and in-wire signaling when using WebRTC DataChannels

– Design of HTML5 web-based OS – Design and development of WebRTC and WebSocket APIs – Adaptation of CMS to Algeria mobile phone operator – Support for Algerian french in num2words Python library – Django and Node.js APIs and connectors for Context Broker IoT server – Cloud storage – Movistar+ Video-on-Demand CDN – Design of encryption mechanism for banking credentials – Reverse engineering of web protocols of spanish banks online web pages

– Design of Javascript, Node.js and HTML5 APIs for WebRTC and server-based communications – Acquired later by Twilio in 2016 – Assistant consultant for WebRTC related tasks – Development of communications server based on roles & privileges with socket.io – Development of Schuko (https://github.com/piranna/Schuko) server to interconnect browsers using WebSockets – Design of REST API library based on JSON objects descriptions – Design of HTML5 web-based OS

– Design and implement passengers information system for Buenos Aires subway – Optimize processing pipelines for Vocento media group digital newspaper library – Development of UI widgets in ActionScript and Flash – Adapt payment platform to spanish market for BBVA bank – Integration of offline Python package manager using virtualenv – Development of unit tests for company in-house CMS – Optimization of in-house developed multi-thread libraries – Development of fully client-side HTTP reverse proxy – Development of RTSP reverse proxy based on Live555 library – C/C++, Boost, code documentation, internationalization

– Integrate Gecko (Mozilla Firefox) web engine inside company SVG player – Design and development of graphic widgets library based on SVG and Javascript, later used for custom windows manager and platform apps – Design and development of web site visitors activity monitor – Design and development of high-performance multiplatform (MacOS X, Windows & Linux) 3D engine – Proposed as C++ team lead

– Advisor of university students – Maintenance of university IT equipment – Security audit of university campus wireless network – Redesign university Data Protection web portal, from IIS + Access to Apache + MySQL, optimization and accessibility certificate