Interviews/Specialty Stacks/Blockchain Engineer

Hire Blockchain Engineers
who actually write contracts that hold under audit

With EasyEnv we build a fit test for the role. Use it to cut the noise at the top of the funnel, or to go deep on the candidates who matter.

You can even evaluate how this person works with AI. So you hire the engineer who can ship, not the one who looks good in a slide.

SolidityFoundry · HardhatEVM · L2Fuzzing · invariantsLive or take-home

Request a Demo Create a Free Account

Real Linux VM

Not a sandbox

systemd, kernel, full toolchain

Browser-based

Zero install for candidates

One link and they are in

Auto-graded

Pass / fail checks per challenge

Plus the full session replay

A blockchain engineer writes code with no rollback. The good ones reason about reentrancy and gas the way backend engineers reason about transactions. EasyEnv hands the candidate a real contract with a real exploit and an audit deadline.

Inside a live interview

What you see when they work.

Real Foundry project, real exploit, every keystroke recorded.

billing-api

AMS

Billing-api

src

billing.py

auth.py

models.py

tests

test_billing.pyM

test_auth.py

pyproject.toml

README.md

Pybilling.py

from decimal import Decimal

def calculate_total(items: list[dict]) -> Decimal:

# Sum line totals using Decimal for currency precision

total = Decimal("0")

for item in items:

total += Decimal(str(item["price"])) * item["qty"]

return total

candidate@chain-workspace:~

alice@dev:~/billing-api$

● mainPython 3.12

Claude · ready

Claude

You

Refactor calculate_total to use Decimal for currency math, and add a test.

Claude

Ask Claude...

Mike

Sam

How it works

Three steps. Zero infra to maintain.

Pick the fit test

Use a ready-made challenge or ask us to build one for your stack. Live, take-home, or both.

Send one link

The candidate clicks. A full Linux workspace boots in their browser. No installs, no VPN, no zoom-share.

Review at 2x

Replay the session, read the auto-graded checks, and decide. Most reviews take under five minutes.

The problem

Why hiring a Blockchain Engineer is hard.

Tutorials cover the happy path. The interview has to surface the edge case.

Gas optimization is taste plus measurement. CVs cannot show either.

Security depth ranges wildly. You need to find the floor.

EVM idioms are easy to fake and hard to actually know.

The fit test

What we measure for a Blockchain Engineer.

Every area runs inside a real production-like workspace. The candidate works in a browser, the session records itself.

Reentrancy and arithmetic

A contract with a classic reentrancy hidden behind a modifier. They find and patch.

Access control

An admin function with a forgotten check. They prove the bypass before they fix.

Upgradeability

A proxy pattern with a storage collision. They diagnose with a slot map.

Gas optimization

A function priced out of usability. They cut gas without breaking the ABI.

Testing discipline

A test suite with no invariants. They add the fuzz test that finds the bug.

AI collaboration

Allow AI for refactors and grade whether they run the full test suite, not just the touched test.

The stack we put in front of them.

Real tools, pre-installed, accessible from the workspace terminal.

SolidityFoundryHardhatforgecastanvilethers.jsviemwagmiOpenZeppelinSlitherEchidnaMythrilTenderlyL2s (Arbitrum, Optimism, Base)

Sample challenges

What a Blockchain Engineer interview looks like.

Pick from our library or ask us to build a challenge for your stack. Each one is a real workspace, not a snippet.

Challenge 01

The withdraw that drains

Scenario

A staking contract that lets a malicious recipient reenter withdraw. Tests and contract are open.

What you learn

Whether they reach for checks-effects-interactions before they reach for a guard.

In the workspace

$ ls challenges/

workspace, runbook.md, README.md

candidate has:

· a real Linux box in the browser
· kubectl, docker, terraform, jq, yq
· cluster, repo and cloud creds pre-wired
· auto-checks running in the background

interviewer sees:

· every keystroke + every command
· terminal + screen recording
· auto-graded pass/fail per check

AI in the loop

Score the engineer, and how they work with AI.

AI is fluent in Solidity and oblivious to gas. EasyEnv records prompts so you see whether the candidate ran forge test and checked the gas snapshot before merging the LLM-suggested refactor.

Allow or block AI per question, not per interview

Full prompt and response history replayed in the review

Score "verifies AI output" as a separate signal

Ready to hire a Blockchain Engineer who ships?

Set up your first interview in under an hour. We will help you build a fit test for this role on your stack.

Request a Demo Create a Free Account

Role FAQ

Hiring a Blockchain Engineer, answered.

Yes. The workspace ships with Anvil and Hardhat configured to fork mainnet or an L2 of your choice.

Yes. viem/wagmi and a sandbox key can be pre-wired to a frontend in the workspace.

No. The workspace runs in their browser. Terminal, editor, ports and dashboards are all served from the EasyEnv workspace, so candidate setup is zero.

Each challenge has automated checks (did the service come back, did the test pass, did the right log message appear) plus a recording your team can replay. Most reviews take under five minutes.

Yes. AI access is a per-interview setting. Block it for fundamentals, then allow it later in the loop to assess AI collaboration separately.

Interviews/Specialty Stacks/Blockchain Engineer

Hire Blockchain Engineers
who actually write contracts that hold under audit

With EasyEnv we build a fit test for the role. Use it to cut the noise at the top of the funnel, or to go deep on the candidates who matter.

You can even evaluate how this person works with AI. So you hire the engineer who can ship, not the one who looks good in a slide.

SolidityFoundry · HardhatEVM · L2Fuzzing · invariantsLive or take-home

Request a Demo Create a Free Account

Real Linux VM

Not a sandbox

systemd, kernel, full toolchain

Browser-based

Zero install for candidates

One link and they are in

Auto-graded

Pass / fail checks per challenge

Plus the full session replay

Inside a live interview

What you see when they work.

Real Foundry project, real exploit, every keystroke recorded.

billing-api

AMS

Billing-api

src

billing.py

auth.py

models.py

tests

test_billing.pyM

test_auth.py

pyproject.toml

README.md

Pybilling.py

from decimal import Decimal

def calculate_total(items: list[dict]) -> Decimal:

# Sum line totals using Decimal for currency precision

total = Decimal("0")

for item in items:

total += Decimal(str(item["price"])) * item["qty"]

return total

candidate@chain-workspace:~

alice@dev:~/billing-api$

● mainPython 3.12

Claude · ready

Claude

You

Refactor calculate_total to use Decimal for currency math, and add a test.

Claude

Ask Claude...

Mike

Sam

How it works

Three steps. Zero infra to maintain.

Pick the fit test

Use a ready-made challenge or ask us to build one for your stack. Live, take-home, or both.

Send one link

The candidate clicks. A full Linux workspace boots in their browser. No installs, no VPN, no zoom-share.

Review at 2x

Replay the session, read the auto-graded checks, and decide. Most reviews take under five minutes.

The problem

Why hiring a Blockchain Engineer is hard.

Tutorials cover the happy path. The interview has to surface the edge case.

Gas optimization is taste plus measurement. CVs cannot show either.

Security depth ranges wildly. You need to find the floor.

EVM idioms are easy to fake and hard to actually know.

The fit test

What we measure for a Blockchain Engineer.

Every area runs inside a real production-like workspace. The candidate works in a browser, the session records itself.

Reentrancy and arithmetic

A contract with a classic reentrancy hidden behind a modifier. They find and patch.

Access control

An admin function with a forgotten check. They prove the bypass before they fix.

Upgradeability

A proxy pattern with a storage collision. They diagnose with a slot map.

Gas optimization

A function priced out of usability. They cut gas without breaking the ABI.

Testing discipline

A test suite with no invariants. They add the fuzz test that finds the bug.

AI collaboration

Allow AI for refactors and grade whether they run the full test suite, not just the touched test.

The stack we put in front of them.

Real tools, pre-installed, accessible from the workspace terminal.

SolidityFoundryHardhatforgecastanvilethers.jsviemwagmiOpenZeppelinSlitherEchidnaMythrilTenderlyL2s (Arbitrum, Optimism, Base)

Sample challenges

What a Blockchain Engineer interview looks like.

Pick from our library or ask us to build a challenge for your stack. Each one is a real workspace, not a snippet.

Challenge 01

The withdraw that drains

Scenario

A staking contract that lets a malicious recipient reenter withdraw. Tests and contract are open.

What you learn

Whether they reach for checks-effects-interactions before they reach for a guard.

In the workspace

$ ls challenges/

workspace, runbook.md, README.md

candidate has:

· a real Linux box in the browser
· kubectl, docker, terraform, jq, yq
· cluster, repo and cloud creds pre-wired
· auto-checks running in the background

interviewer sees:

· every keystroke + every command
· terminal + screen recording
· auto-graded pass/fail per check

AI in the loop

Score the engineer, and how they work with AI.

AI is fluent in Solidity and oblivious to gas. EasyEnv records prompts so you see whether the candidate ran forge test and checked the gas snapshot before merging the LLM-suggested refactor.

Allow or block AI per question, not per interview

Full prompt and response history replayed in the review

Score "verifies AI output" as a separate signal

Ready to hire a Blockchain Engineer who ships?

Set up your first interview in under an hour. We will help you build a fit test for this role on your stack.

Request a Demo Create a Free Account

Role FAQ

Hiring a Blockchain Engineer, answered.

Yes. The workspace ships with Anvil and Hardhat configured to fork mainnet or an L2 of your choice.

Yes. viem/wagmi and a sandbox key can be pre-wired to a frontend in the workspace.

No. The workspace runs in their browser. Terminal, editor, ports and dashboards are all served from the EasyEnv workspace, so candidate setup is zero.

Each challenge has automated checks (did the service come back, did the test pass, did the right log message appear) plus a recording your team can replay. Most reviews take under five minutes.

Yes. AI access is a per-interview setting. Block it for fundamentals, then allow it later in the loop to assess AI collaboration separately.

How to Hire a Blockchain / Smart Contract Engineer | EasyEnv | EasyEnv

Hire Blockchain Engineerswho actually write contracts that hold under audit

What you see when they work.

Three steps. Zero infra to maintain.

Pick the fit test

Send one link

Review at 2x

Why hiring a Blockchain Engineer is hard.

What we measure for a Blockchain Engineer.

Reentrancy and arithmetic

Access control

Upgradeability

Gas optimization

Testing discipline

AI collaboration

The stack we put in front of them.

What a Blockchain Engineer interview looks like.

The withdraw that drains

Score the engineer, and how they work with AI.

Ready to hire a Blockchain Engineer who ships?

Hiring a Blockchain Engineer, answered.

Hire Blockchain Engineerswho actually write contracts that hold under audit

What you see when they work.

Three steps. Zero infra to maintain.

Pick the fit test

Send one link

Review at 2x

Why hiring a Blockchain Engineer is hard.

What we measure for a Blockchain Engineer.

Reentrancy and arithmetic

Access control

Upgradeability

Gas optimization

Testing discipline

AI collaboration

The stack we put in front of them.

What a Blockchain Engineer interview looks like.

The withdraw that drains

Score the engineer, and how they work with AI.

Ready to hire a Blockchain Engineer who ships?

Hiring a Blockchain Engineer, answered.

Hire Blockchain Engineers
who actually write contracts that hold under audit

Hire Blockchain Engineers
who actually write contracts that hold under audit