Language and runtime
Java 17 and 21concurrencyJVM tuninggarbage collectionthread dumpsJava Flight Recorder
Messaging and streaming · screened by AceMQ
Hire senior Java developers for production platforms
Conntal places senior Java developers who can read a thread dump and a GC log, not just build features: Spring, Apache Tomcat and VMware GemFire on messaging and caching platforms. Every candidate is screened by an AceMQ practitioner on a real production stall before you see them. Contract, contract-to-hire or direct.
Indicative rate: from $80/hr nearshore or offshore and $120/hr onshore. See what moves it.
Contract, contract-to-hire or direct · onshore, nearshore, offshore · reviewed 31 October 2026
- Screen owner
- Java and middleware lead · AceMQDelivers Java and Apache Tomcat work for AceMQ clients.
- Titles we place
- Java developer · Senior Java developer · Spring Boot developer · Java backend engineer · Java platform engineer
- Platforms we screen on
- Java 17 and 21concurrencyJVM tuninggarbage collectionthread dumpsJava Flight Recorder
Rates
What a contract Java developer costs
Senior contract Java developer rates start at $80/hr nearshore or offshore and $120/hr onshore. These are indicative from-rates, last reviewed 31 October 2026.
| Location model | From (USD per hour) | Where engineers are based |
|---|---|---|
| OnshoreHighest rate | $120/hr | US-based, on client time zones, cleared where the engagement requires it. |
| NearshoreOur default recommendation | $80/hr | Latin America and Canada, four hours or less of overlap loss, same working day. |
| OffshoreLowest rate | $80/hr | Europe, India and South East Asia. |
What moves the number
- Platform scarcity. The fewer engineers who have run Java in production, the higher the rate.
- Seniority. The figures are for senior engineers; staff and principal levels cost more.
- Clearance and residency. Cleared or on-site work narrows the pool and sits in the onshore column.
- Term. Length, hours and the engagement model change the rate; contract-to-hire and direct placement are priced differently.
Indicative from-rates for senior contract engineers, USD per hour. The final rate depends on platform scarcity, seniority, clearance and term.
The screen
How we vet Java developers: the published screen
Every Java developer is screened on the scenario below by the Java and middleware lead at AceMQ. The senior and mid answers are published so you can judge our bar before you engage us, and candidates know what they are walking into.
The screen · Java developer
Conntal Vetting Standard
Scenario put to the candidate
A Spring Boot service on Tomcat answers in 40 milliseconds for most requests, then stalls for several seconds every few minutes. CPU is low, the heap looks fine, and the request thread pool shows every thread busy. What do you check?
Vetted by
Java and middleware lead · AceMQ
A senior answer contains
- Takes several thread dumps a few seconds apart and reads what the busy threads are waiting on, rather than guessing from the metrics.
- Looks for a shared lock or a blocking call without a timeout, such as an exhausted JDBC connection pool or a slow downstream service.
- Lines the stalls up against the GC log to rule pauses in or out, instead of assuming a leak because the heap is large.
- Fixes it with timeouts and isolation, and explains why raising the maximum thread count only hides the problem.
Where a mid answer stops
- Raises the thread pool size or the heap first, then waits to see whether it recurs.
- Restarts the service and treats the stall as a one-off.
- Cannot say how to tell a blocked thread from a busy one in a thread dump.
What we screen on
Java skills we screen for
Java candidates are screened on language and runtime, frameworks and application servers, among others, against the stack you actually run rather than a generic checklist.
Frameworks
Spring BootSpring FrameworkSpring IntegrationHibernate and JPA
Application servers
Apache Tomcatthread poolsconnection poolsTLS and connectors
Caching and data grids
VMware GemFireApache GeodeRedisregions and partitioning
Messaging from Java
JMSSpring AMQPSpring KafkaIBM MQ classes for JMSRabbitMQ Java client
Delivery
MavenGradleJUnitDockerKubernetes
Titles this covers
Java job titles we place
We place 7 titles in this area, from Java developer to GemFire developer. They overlap and are used inconsistently between companies, so tell us the outcome you need and we will tell you which title actually fits it.
- Java developer
- Senior Java developer
- Spring Boot developer
- Java backend engineer
- Java platform engineer
- Tomcat engineer
- GemFire developer
Engagement
Ways to hire Java developers
Platform work usually starts with a defined piece of change and becomes ongoing ownership, which is why most Java developers engagements begin on contract. All three models are available, in any location model.
Contract
A vetted engineer embedded in your team for a defined term.
Hourly, billed against an approved SOW. Most common for migrations, upgrades and capacity surges where the work has an end date.
Contract staffingContract-to-hire
Work together first, convert when it is obviously working.
A defined conversion window and a pre-agreed fee, so the decision to hire is a business decision rather than a negotiation.
Contract-to-hire staffingDirect placement
A permanent hire, screened to the same standard.
One-time fee against first-year base. Used where the role is a long-term platform owner rather than project capacity.
Direct placement staffingNot a fit if
When to look elsewhere for Java developers
We are the wrong choice if any of these describe your role, and we would rather say so on the first call.
- The work is generalist CRUD web development with no platform, concurrency or caching concerns.
- You want Java consulting or an architecture review delivered as a project; AceMQ does that, we place developers.
- You need an entry-level or junior Java hire; the screen is written for senior engineers.
How it works
How hiring Java developers through Conntal works
- 01
Scope
A practitioner scopes the role
An engineer who runs this technology reads your brief and tells you what is missing from it. Most briefs we receive ask for the wrong seniority or the wrong title. - 02
Screen
We screen, then shortlist
Sourcing is ours; the technical decision belongs to the vetting practitioner. You only see candidates who passed the scenario on this page. - 03
Start
Start, convert or replace
Contract, contract-to-hire or direct. If the fit is wrong we say so first and replace rather than defend the placement.
Screen owner
Who vets our Java developers: Java and middleware lead, AceMQ
Delivers Java and Apache Tomcat work for AceMQ clients, on the messaging and caching platforms AceMQ supports.
FAQ
Java developers: what buyers ask
Something not covered here? Send the requirement and a practitioner answers it, not a sales queue.
How much does a contract Java developer cost per hour?
Indicative senior contract from-rates are $80/hr nearshore or offshore and $120/hr onshore (USD, reviewed 31 October 2026). The final rate depends on platform scarcity, seniority, clearance and term. Contract-to-hire and direct placement are priced differently, and the delivery models page sets out how.
How fast can a Java developer start?
We do not promise a start date before we have seen the brief. A practitioner reads it, usually within one business day, and tells you whether we can staff it. Timing after that depends on the stack, the seniority and the location model.
Do you staff generalist Java web developers?
Mostly no. The screen is built for production platforms: concurrency, garbage collection, thread and connection pools, caches and messaging. If your role is CRUD web work, say so on the brief and we will tell you plainly whether we are the right fit.
Do your Java developers know GemFire?
Some do, and it is screened separately: regions, partitioning, persistence, and what happens to a region when a member leaves. Tell us the GemFire or Geode version you run and we will confirm depth before sourcing.
What is the difference between a Java developer and a Java platform engineer?
A Java developer builds features in application code. A Java platform engineer owns how the services run: JVM settings, the application server, caches, messaging and what happens under load. We screen the two differently, and the scenario on this page is the platform one.
Do you staff Tomcat administrators?
Yes, where the role is the platform itself: connectors, thread and connection pools, TLS, memory and the upgrade path. The stall scenario on this page is the first thing we put to a candidate.
Who runs the technical screen for Java developers?
The screen is owned by the Java and middleware lead at AceMQ. It is a production scenario, and the senior and mid answers are published on this page so you can judge the bar before you engage us.
Can we convert a contractor to full time, and what does it cost?
Yes. Contract-to-hire sets a conversion window and a pre-agreed fee at the start, so converting is a business decision rather than a negotiation. The fee is agreed per engagement; ask for it with your brief.
What if the placement does not work out?
If the fit is wrong we say so first and replace the engineer rather than defend the placement. Replacement terms are agreed per engagement, so ask for them with your brief.
Do you also deliver Java consulting or support?
Not through Conntal. We place individual engineers into your team on contract, contract-to-hire or direct hire. If you want a project delivered or the platform supported as a service, AceMQ does that directly at acemq.com.
Related
Related roles
Need Java delivered as a project or supported as a service instead of staffed? AceMQ does that directly.
Need Java developers? Start with the brief.
Send the requirement and an engineer who runs this technology will tell you what is missing before we source anyone.