// US-based Java developers
Free project plan & cost estimate in 48 hours.
Senior Java developers, based in the US, working your hours
Enterprise back-ends, Spring Boot services, and legacy modernization, built by engineers who have kept big Java systems running.
- Interview engineers before you pay anything
- 100% U.S.-based, working your hours
- No brief or spec needed to get started
First 5 Dev Hours Free
Project plan. Roadmap. Cost & ROI estimation.
Real engineers. Real conversations.
Talk to an engineer. Not a salesperson.
Free · No commitment · Project-focused call
Most teams interview matched engineers within a week
Not the right fit? We bring in a replacement
Get your free project plan
Three quick steps. No brief needed.
Free · No commitment · Reply within one business day
// teams we've worked with
“NextGen scaled us from 2 to 7 dedicated engineers in under a quarter. Enterprise-grade capacity, zero agency drag.”
Sound familiar?
- Hiring a senior Java developer full-time is taking months.
- Your Java codebase has grown messy and every change breaks something else.
- Offshore hand-offs and time-zone gaps turn one-day fixes into week-long threads.
- You need someone senior enough to make decisions, not just close tickets.
What our Java engineers build
Spring Boot services
Well-tested APIs and microservices on AWS, Azure, or your own servers.
Legacy modernization
Old Java upgraded to current versions, piece by piece, without downtime.
Integrations
Messaging, batch jobs, and connections to the systems your business runs on.
How it works
- 01
Pick a time
Book a 30-minute project call directly in our calendar.
- 02
Talk through the problem
Tell us what needs building, what's stuck and what success looks like. No spec needed.
- 03
Your plan in 48 hours
Get your project plan, roadmap, cost and ROI estimates. The plan is yours to keep.
- 04
First 5 dev hours free
Agree the scope with our team. Decide whether to continue before any paid work begins.
Common questions
Will this turn into a sales pitch?
No. The call is about your project: what needs building, what's stuck, and whether we have the right engineers. If we're not a fit, we'll say so.
What do I get for free?
A project plan, roadmap, cost estimate and ROI estimate within 48 hours of your project call. Your first 5 development hours are free, too. We agree the scope and any paid work with you before proceeding.
Do I need a spec or brief?
No. Tell us the problem in plain words and we'll help shape the scope with you.
Are the engineers really in the U.S.?
Yes. Every engineer lives and works in the United States. No offshore hand-offs, and that's in the contract.
What our clients say
"NextGen scaled us from 2 to 7 dedicated engineers in under a quarter. Enterprise-grade capacity, zero agency drag."
"Their R&D tax credit workflow platform paid for itself in the first filing season."
"AI-native from day one. Our IRS transcript pipeline runs 24/7 without a human in the loop."
"Property tax appeals used to take weeks. Their comp analysis tooling turned it into hours."
"The AI intake agent handles our tier-1 patient calls with a hand-off cleaner than our old call center."
"POS, inventory, ordering — all unified. We finally have one source of truth across every location."
"The procurement platform paid for itself in the first quarter of use."
"They shipped our matching engine in 6 weeks. Our old team would've taken 6 months."
"Enterprise-grade delivery without the enterprise-agency price tag."
"Their team plugged into our sprint on day one. Zero ramp time."
"NextGen scaled us from 2 to 7 dedicated engineers in under a quarter. Enterprise-grade capacity, zero agency drag."
"Their R&D tax credit workflow platform paid for itself in the first filing season."
"AI-native from day one. Our IRS transcript pipeline runs 24/7 without a human in the loop."
"Property tax appeals used to take weeks. Their comp analysis tooling turned it into hours."
"The AI intake agent handles our tier-1 patient calls with a hand-off cleaner than our old call center."
"POS, inventory, ordering — all unified. We finally have one source of truth across every location."
"The procurement platform paid for itself in the first quarter of use."
"They shipped our matching engine in 6 weeks. Our old team would've taken 6 months."
"Enterprise-grade delivery without the enterprise-agency price tag."
"Their team plugged into our sprint on day one. Zero ramp time."
Hire US-based Java developers for Spring Boot services, JVM upgrades, and established backend applications. A Java 21 API using Spring Boot 3 has different needs from a Java 8 application running on an older servlet container, so start with your actual runtime and dependencies. Our engineers are senior, many have 10+ years of experience, and every engineer lives and works in the US.
Set priorities around concrete work such as Hibernate query tuning, Maven dependency cleanup, Kafka consumers, or a javax-to-jakarta migration. JUnit 5 and Testcontainers can support regression testing, while Java Flight Recorder helps investigate runtime bottlenecks. Engineers join your standups and follow your working hours. An NDA and full IP assignment come before code access; a 15-minute call is the next step.
Frequently asked questions
- What skills should a senior Java developer have for Spring Boot?
- Look beyond annotation familiarity. A senior Spring Boot developer should explain transaction boundaries, dependency injection, connection pooling, and failure handling in outbound calls. Use your persistence layer and messaging setup to guide questions. For Spring Boot 3 projects, check familiarity with Java 17 or later, Jakarta namespaces, Spring Security configuration, and integration testing against real dependencies.
- How do we plan a Java 8 to Java 21 migration?
- Inventory libraries, build plugins, application servers, and removed JDK components before choosing migration steps. Compile and test on the target runtime, investigate reflective-access assumptions, and check deployment images. Separate framework upgrades where practical so failures remain understandable. Compare production-like workloads with Java Flight Recorder and existing latency baselines rather than assuming a newer JDK automatically improves performance.
- Can a Java developer improve slow Hibernate queries?
- First determine whether the delay comes from SQL execution, excessive round trips, entity hydration, or connection pool waits. Hibernate statistics and database query plans help distinguish these causes. Common work includes fixing N+1 queries, reviewing fetch strategies, and testing pagination behavior. Changes should preserve transaction semantics and be checked against realistic data volumes, not only small fixtures.
- Should we use Java virtual threads in our backend?
- Java 21 virtual threads can help applications with many blocking I/O tasks, but they do not make CPU-heavy code faster. Review framework support, downstream concurrency limits, and ThreadLocal usage before adoption. On Java 21, also investigate pinning behavior. Load tests should show how database pools and external services behave when more requests can wait concurrently.
- How does hiring a US-based Java engineer work?
- Start with a 15-minute call covering your JDK, Spring version, build system, and immediate backlog. Most teams interview matched engineers within a week of the first call. There is no offshore subcontracting, and engineers attend your standups during your working hours. If the fit falls short, we bring in a replacement with a proper hand-over.
- Are your developers really based in the US?
- Yes. Every engineer lives and works in the United States. No offshore subcontracting and no hand-offs to another team. That's written into the contract.
- How fast can someone start?
- Most teams interview matched engineers within a week of the first call. Start dates depend on your interview process.
Related reading
- How to hire a software developer
What to check before you sign.
- Hiring test for senior engineers
How to vet senior talent fast.
- Senior engineer salary guide 2026
What the market pays.
- Onshore vs offshore vs nearshore
The honest tradeoffs.
- Forward deployed engineers
Need an owner, not just capacity?
- Resource library
Every guide and benchmark we publish.
Start your project request
Tell us what you're building — engineering capacity, AI, QA, cloud, or a fixed-scope software engagement. Our NYC team responds within one business day.
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