Detail-oriented and self-motivated Software Engineer based in London, interested in performance optimization. Proficient in particular in Rust, Go, C and eBPF.

Employment

Sep. 2020 - Now   Software Engineer, Cloudflare, London & Remote: Denial of Service (DoS) team

  • Main responsibilities: maintaining and improving automated mitigation systems against DoS attacks
  • Reworked with a colleague the data pipeline to display network analytics to customers. It involved mainly data extraction using eBPF, efficient and performant storage in ClickHouse and a public facing GraphQL API
  • Extended and automated data extraction for public reports like “Network-layer DDoS attack trends for Q4 2020”
  • Hand-optimized eBPF assembly, C code, ClickHouse tables and materialized views

✓   C, eBPF, XDP, Rust, Go, Docker, TCP, UDP, dos attacks, ClickHouse, GraphQL

Mar. - Aug. 2020   Software Developer Intern, Cloudflare, London & Remote: Denial of Service (DoS) team

✓   eBPF, XDP, TCP, kernel probes

Jun. - Aug. 2019   Software Developer Intern, SnT, Luxembourg: Interdisciplinary Center for Security, Reliability and Trust (SnT), a research lab of the University of Luxembourg. securityandtrust.lu

  • Aim: explore performance analysis technics with eBPF (extended Berkeley Packet Filter)
  • Wrote IP-whitelisting tool using XDP for DDoS protection of a Ripple blockchain connector
  • Extended Vector monitoring tool with additional eBPF modules : packet analysis (HTTP & WebSocket, UDP & DTLS), garbage collector visualization for NodeJS using USDT probes
  • Co-authored a research paper outlining innovative performance monitoring schemes
  • Worked in English on a daily basis.

✓   eBPF at different levels, Docker, Python, Go, TCP, UDP, Websocket

Talks & Papers

Aug. 2020   Linux Plumbers Conference 2020 (talk & paper): Evaluation of Tail Call Costs in eBPF

Aug. 2020   Master Thesis: Impact of Indirect Calls within eBPF and Changes to Reduce this Impact

Aug. 2019   NOMS 2020 Conference (co-author): The Rise of eBPF for Non-Intrusive Performance Monitoring

Education

2017 - 2020   Télécom Nancy, Nancy, France: MSc CS, specializing in Software Engineering

Masters of Science in Computer Science, covering software engineering and project management

2015 - 2017   Lycée A. Fournier, Bourges, France: two-year course equiv. to a BSc in Mathematics and Physics

Preparation for the highly competitive nationwide entrance exams for French Grandes Écoles

Selected School Projects

2018 - 2019   Full compiler: Tiger language (team of 4 people, 6 months)

  • Wrote a grammar for the language with ANTLR, constructed the abstract syntax tree (AST)
  • Did semantic analysis on the AST, generated assembly code (function, loops, conditional branches)

✓   Java, ANTLR, formal language theory

Skills

Working knowledge

Rust, C, Go, SQL (ClickHouse, SQLite), Python, Docker, Linux, Jira, Gitlab

Basic knowledge

Java, OCaml, HTML/CSS/JavaScript,
key-value database (LMDB)

Languages

English (TOEIC 935, full professional proficiency) • French (native) • German

Selected Personal Software Projects

For links to source-codes and open-source contributions, please visit my website at joly.pw/open-source

2019 - 2021   Sesters: tool to extract price tags from plain text, for conversion from one currency to another

✓   Rust (noteworthy package used: serde, clap, reqwest), LMDB, Web API

2014 - present   Open-source contributions: please see github.com/cljoly for more details

Interests

Sports: Judo in team, Climbing, Yoga

Reading: novels, non-fiction (press, books)