Senior Software Engineer – Ledger


About Us

Ledger was launched in 2014 by eight experts with complementary backgrounds in embedded security, cryptocurrencies and entrepreneurship, united around the idea of creating secure solutions for blockchain applications, when this market was still in its infancy.

What you will do

Required profile

  • Engineer profile with at least 5 years of experience in Java/ Scala.
  • Master NoSQL DB issues (Cassandra or ScyllaDB)
  • Throubleshooting & Problem solving oriented
  • Good knowledge of *nix operating systems.
  • Open source lover (90% of our code is available on Github)
  • Experience with continuous integration solutions.
  • Capable of self-training and monitoring of backend-oriented technologies.
  • Having a strong interest in cryptocurrencies and wishing to work with blockchain technology.
  • Knowledge of AWS solutions is appreciated.

What we are looking for


  • Develop a technological stack to explore the contents of a blockchain (Bitcoin, Ethereum, Ripple,Monero …).
  • Build stable platform with new technological stack.
  • Optimize the overall performance of the application.
  • Conduct benchmarks to identify bottlenecks.
  • Creation of the software architecture of the blockchain explorer.
  • Develop blockchain abstraction technology to easily integrate new crypto-currencies.
  • Set up monitoring for server applications to detect unexpected failures / behavior.
  • Set up continuous integration to deploy / test the blockchain explorer.

Additional Information

  • Contract type: Full-Time
  • Location: Paris, France (75002)
  • Education Level: Master's Degree
  • Experience Level: > 5 years
  • Possible remote work