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Smart Contract Hacker and Developer Internship

$12k - $17k

This job is closed

Smart Contracts are a critical part of decentralized applications. The difficulty is not about what they should do but about what they should not do. Programming them requires adversarial thinking. "How could someone call a contract function to performed a non-authorized action?".
As an intern, you will develop this adversarial thinking by trying to hack smart contracts (of Kleros repository or in a White Hat manner).
You will write and review smart contracts for Kleros and related applications.


  • This internship is open for bachelor or master students in Computer Science or related fields. You can also apply if you just finished a degree which does not make internships mandatory.
  • Has read the solidity documentation: https://media.readthedocs.org/pdf/solidity/develop/solidity.pdf
  • Ability to produce well-designed code.
  • Network security and defensive programming.
  • Ability to learn new technologies and languages to cope with the fast developments in the blockchain space.
  • Ability to work autonomously and take initiatives.
  • Interest in blockchain applications.
  • Basic knowledge of solidity.
  • Be available full time for the period of the internship.

Desired qualifications:

  • Languages and frameworks used in the development of Ethereum dapps: Solidity.
  • Git/Github open source workflow.
  • Blockchain technical knowledge and blockchain culture.
  • Good level of English.


  • The internship compensation is 800€/month (net) for bachelor students and 1200€/month for masters students.
  • If it goes well it can end up into a permanent position after you finish your studies.
  • Work in a coworking hosting blockchain related events. (Possibility to work remotely if on-site is not possible due to visa or health issues)

Want to Apply?

Send us an intro answering the following questions:

1) What is the most interesting problem you’ve worked on?

2) What is the address of the KlerosLiquid smart contract on the mainnet that https://court.kleros.io uses and the value of its maxDrawingTime variable? Let’s test your sleuthing skills!

Kleros focuses on Blockchains and Legal Tech. Their company has offices in Paris. They have a small team that's between 11-50 employees. To date, Kleros has raised $5.66M of funding; their latest round was closed on June 2020.

You can view their website at http://kleros.io or find them on Twitter, Facebook, and LinkedIn.