Interviews/Application Development/Java Developer

Hire Java Developers
who actually ship JVM services that survive scale

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.

Java 21+Spring · QuarkusGC · JFRJMH benchmarksLive 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 great Java developer thinks in terms of heap, latency and clarity at the same time. The good ones read a flight recording, write a JMH benchmark, and reach for modern Java idioms instead of inheritance. EasyEnv hands the candidate a real service with a real latency complaint and a profile that names the cause.

Inside a live interview

What you see when they work.

Real JVM, real flight recording, 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@jvm-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 Java Developer is hard.

Java fluency ranges from Java 8 muscle memory to Java 21 fluency. The interview has to surface it.

GC tuning is folklore for most. Few can read a JFR.

Memory leaks are easy to talk about and hard to find.

Concurrency: synchronized, AtomicX, virtual threads. Choice signals depth.

The fit test

What we measure for a Java Developer.

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

Memory and GC

A service that fills the heap on a known endpoint. They read the JFR, not the stack overflow answer.

Profiling and benchmarking

A hot path with a hidden cost. They prove the issue with JMH before they fix.

Modern idioms

Records, sealed types, pattern matching, virtual threads. They use them where it helps.

Concurrency choices

A task with shared state. They pick between synchronized, AtomicX or structured concurrency and explain why.

Build and dependencies

A Maven or Gradle build with a slow phase. They cut without breaking the artifact.

AI collaboration

Allow AI for refactors and grade whether they re-ran JMH after the LLM-suggested change.

The stack we put in front of them.

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

Java 21Spring BootQuarkusMicronautHibernateMavenGradleJUnitJMHJFRjstackjcmdReactorRxJavaKafkaPostgreSQL

Sample challenges

What a Java Developer 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 OOM on a known endpoint

Scenario

A REST endpoint that leaks objects. A JFR is captured and open in JMC.

What you learn

Whether they read retained-set first or guess at the cause.

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 writes Java that compiles and allocates. EasyEnv records prompts so you see whether the candidate captured a JFR after 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 Java Developer 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 Java Developer, answered.

Yes. The workspace can be pre-loaded with either framework and a representative app.

Yes. Reactor, RxJava and Mutiny can all be wired with a real backpressure scenario.

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/Application Development/Java Developer

Hire Java Developers
who actually ship JVM services that survive scale

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.

Java 21+Spring · QuarkusGC · JFRJMH benchmarksLive 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 JVM, real flight recording, 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@jvm-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 Java Developer is hard.

Java fluency ranges from Java 8 muscle memory to Java 21 fluency. The interview has to surface it.

GC tuning is folklore for most. Few can read a JFR.

Memory leaks are easy to talk about and hard to find.

Concurrency: synchronized, AtomicX, virtual threads. Choice signals depth.

The fit test

What we measure for a Java Developer.

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

Memory and GC

A service that fills the heap on a known endpoint. They read the JFR, not the stack overflow answer.

Profiling and benchmarking

A hot path with a hidden cost. They prove the issue with JMH before they fix.

Modern idioms

Records, sealed types, pattern matching, virtual threads. They use them where it helps.

Concurrency choices

A task with shared state. They pick between synchronized, AtomicX or structured concurrency and explain why.

Build and dependencies

A Maven or Gradle build with a slow phase. They cut without breaking the artifact.

AI collaboration

Allow AI for refactors and grade whether they re-ran JMH after the LLM-suggested change.

The stack we put in front of them.

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

Java 21Spring BootQuarkusMicronautHibernateMavenGradleJUnitJMHJFRjstackjcmdReactorRxJavaKafkaPostgreSQL

Sample challenges

What a Java Developer 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 OOM on a known endpoint

Scenario

A REST endpoint that leaks objects. A JFR is captured and open in JMC.

What you learn

Whether they read retained-set first or guess at the cause.

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 writes Java that compiles and allocates. EasyEnv records prompts so you see whether the candidate captured a JFR after 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 Java Developer 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 Java Developer, answered.

Yes. The workspace can be pre-loaded with either framework and a representative app.

Yes. Reactor, RxJava and Mutiny can all be wired with a real backpressure scenario.

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 Java Developer | JVM Interviews | EasyEnv | EasyEnv

Hire Java Developerswho actually ship JVM services that survive scale

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 Java Developer is hard.

What we measure for a Java Developer.

Memory and GC

Profiling and benchmarking

Modern idioms

Concurrency choices

Build and dependencies

AI collaboration

The stack we put in front of them.

What a Java Developer interview looks like.

The OOM on a known endpoint

Score the engineer, and how they work with AI.

Ready to hire a Java Developer who ships?

Hiring a Java Developer, answered.

Hire Java Developerswho actually ship JVM services that survive scale

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 Java Developer is hard.

What we measure for a Java Developer.

Memory and GC

Profiling and benchmarking

Modern idioms

Concurrency choices

Build and dependencies

AI collaboration

The stack we put in front of them.

What a Java Developer interview looks like.

The OOM on a known endpoint

Score the engineer, and how they work with AI.

Ready to hire a Java Developer who ships?

Hiring a Java Developer, answered.

Hire Java Developers
who actually ship JVM services that survive scale

Hire Java Developers
who actually ship JVM services that survive scale