This sounds like a basic question. It's worth answering precisely because what you need depends entirely on what you're building.

At the junior level:

Developers implementing defined features, writing unit tests, fixing bugs, learning the codebase, and gradually taking ownership of smaller components. Useful for scale once a senior developer has established the architecture. Not useful as your first technical hire.

At the mid-level:

Developers who can own features end-to-end, make local architectural decisions, write production-quality code without close supervision, and contribute meaningfully to technical discussions. This is the most common hire for growing teams that need to scale delivery capacity without rebuilding leadership.

At the senior end:

Developers who design systems, make architectural decisions that will affect the product for years, mentor junior team members, lead technical planning, and translate complex business requirements into technical approaches. Often the most critical hire — and the most expensive and hardest to find.

A Java full-stack developer:

‍Additionally handles frontend work — building user interfaces using frameworks like React or Angular alongside the Java backend. Useful for smaller teams where having one person own a complete feature from database to UI is more efficient than maintaining separate frontend and backend specialisms.

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Know which of these you actually need before you write a job description. Hiring a senior Java developer for junior-level work wastes their skills and your budget. Hiring a junior Java developer for senior-level architectural work produces technical debt that compounds painfully.

Core Technical Skills of a Java Developer

Java fundamentals.

Object-oriented programming, data structures, collections, algorithms, multithreading, and memory management. These are non-negotiable at any seniority level and form the baseline competency assessment for any technical interview.

Spring framework.

Spring Boot specifically is the industry standard for Java backend development. If your Java developer doesn't know Spring Boot, they're working with one hand tied behind their back. Spring Security, Spring Data JPA, and Spring MVC are valuable extensions of this.

Database knowledge.

Proficiency with relational databases (MySQL, PostgreSQL) and the ability to write and optimise SQL. Understanding of ORM frameworks like Hibernate. Bonus for familiarity with NoSQL databases (MongoDB, Redis) for appropriate use cases.

API development.

Building RESTful APIs is a core Java developer skill in any modern stack. GraphQL experience is increasingly relevant. Understanding of authentication patterns (OAuth 2.0, JWT) is essential for any product where users log in.

Cloud platforms.

AWS, Google Cloud, and Azure are now fundamental to how Java applications are deployed and scaled. Developers who've never worked with cloud infrastructure are increasingly limited in their usefulness for modern builds.

Microservices architecture.

Understanding how to design and build distributed systems — services that communicate via APIs rather than monolithic codebases — is a baseline expectation for senior Java developers.

DevOps basics.

CI/CD pipelines (Jenkins, GitHub Actions), containerisation (Docker), version control (Git), and basic infrastructure-as-code concepts. Java developers don't need to be DevOps engineers, but they should be able to operate within modern deployment pipelines without requiring hand-holding.

Soft Skills of a Java Developer

Communication.

The ability to explain technical decisions in plain English — to a non-technical founder, a product manager, or a client — is genuinely rare in technical teams and genuinely valuable. Developers who can only communicate effectively with other developers create information bottlenecks that slow everything down.

Adaptability.

Java as a language and ecosystem moves. Spring Boot versions change. Cloud platforms evolve. A developer who learned Java deeply five years ago and hasn't kept up is a different proposition to one who actively follows the ecosystem and has integrated AI-assisted coding tools into their daily workflow. The latter operates materially faster and produces materially better output.

Ownership mentality.

There's a meaningful difference between a developer who completes tickets and a developer who cares whether the product they're building actually works well. The second type — who flags problems before they become bugs, who asks why before building something that seems wrong — is worth significantly more than the first.

Most Java developer job descriptions are written by copying and pasting from another job description and adding the company name. The result is indistinguishable from the 50 other ads that appeared that week and does nothing to attract the specific person you're actually looking for.

Here are some tips to write a Java developer job description that works:

Open with the product, not the company.

What are they actually building? What problem does it solve? What's technically interesting about the challenge? Developers choose roles based partly on what they'll be working on — a compelling technical problem is more attractive than a generic statement about your company culture.

Be specific about the stack.

Spring Boot 3.x, PostgreSQL, AWS, Docker, GitHub Actions — this level of specificity attracts candidates who know those tools and filters out candidates who'd be learning on the job. Generic "Java and associated technologies" attracts everyone and tells no one anything useful.

Be honest about seniority expectations.

"5+ years of Java experience" as the only differentiator between junior and senior is lazy shorthand. Describe the actual responsibilities. Who will they work with? What decisions will they own? What does success look like in the first three months?

Mention salary.

Developers overwhelmingly prefer job ads that include salary information and overwhelmingly skip those that don't. "Competitive salary depending on experience" is what companies write when they haven't decided what to pay, and candidates read it as such.

Include something genuine about the team and working style.

Fully remote or hybrid? Async or synchronous? Small startup or established engineering team? These things matter to the person reading and including them makes the ad feel like it was written by a human rather than generated from a template.

This is the part that most companies get wrong, partly because vetting developers requires technical knowledge that non-technical hiring managers don't have, and partly because the industry's standard approach — CVs, phone screens, generic technical tests — filters for who looks good on paper rather than who can actually do the job.

A better process:

Stage 1: The technical screen.

Use an automated assessment tool — HackerRank, Codility, or TestGorilla all offer Java-specific assessments — to filter candidates on core competency before anyone's time is invested in calls. These should test actual problem-solving in Java, not trivia about Java syntax. Budget 45-60 minutes maximum. Anything longer loses good candidates who have jobs and other options.

Stage 2: The technical interview.

This should involve someone who can actually evaluate the answers — an in-house senior developer, a fractional CTO, or a trusted technical advisor. Ask about real architectural decisions, not textbook definitions. "Tell me about a time you made a technical decision you'd make differently now" reveals more than "explain the difference between an interface and an abstract class."

Stage 3: The practical test.

A short, paid piece of real work — reviewing a small codebase and explaining what you'd improve, or building one specific feature with a defined brief. Two to four hours maximum, compensated at a reasonable rate. What you're evaluating: quality of code, quality of thinking, quality of communication about their decisions.

Stage 4: The conversation.

Not an interrogation. An honest discussion about the role, the team, the product, and the expectations on both sides. What are they looking for? What are their concerns? Are there things about this role that might not work for them?

The goal of this process is not to find someone who performs well under interview conditions — it's to find out how someone thinks and works. These are related but not identical things, and optimising for one while ignoring the other is why many technical hires look good on paper and disappoint in practice.

The default assumption for most UK companies is that "hiring a Java developer" means a permanent, in-house employee. This assumption deserves questioning, because it is neither the only option nor always the best one.

Hiring Java Developers In-House

Gives you alignment, cultural integration, and long-term ownership of the product. It also takes 3-6 months from job posting to productive contribution (assuming the candidate exists, the hiring process works, and the person doesn't leave during the notice period). The annual cost of a mid-level Java developer in the UK runs to £55,000-£80,000 in salary alone — add employer NI, pension, equipment, management overhead, and the real cost sits at £70,000-£100,000+ per year. And if it doesn't work out, you're dealing with a lengthy performance management process.

Hiring Dedicated Remote Java Developers

Through a staff augmentation partner gives you access to a global talent pool, typically at 40-65% of UK employment costs, with significantly faster time-to-productivity and without the overhead and risk of permanent headcount. Dedicated developers are embedded in your team — attending standups, using your tooling, operating in overlapping time zones — but managed externally in terms of HR, payroll, and logistics.

The objections to this model are familiar: quality, communication, time zones, accountability. They're also increasingly outdated when the right partner is involved. A development from India who has been through a rigorous multi-stage vetting process, trained on AI-native development workflows, and managed by an experienced team doesn't differ meaningfully from a UK-based hire in the ways that matter for product quality. They differ considerably in cost.

For a growing company with an existing tech team that needs to scale without the overhead and timeline of traditional hiring, dedicated remote Java developers are worth taking seriously.

Costs vary significantly by model, seniority, and geography. Here's an honest breakdown:

UK in-house hire (permanent)

• Junior: £35,000-£50,000/year salary + ~30% on-costs = £45,000-£65,000 fully loaded

• Mid-level: £55,000-£75,000/year + on-costs = £72,000-£98,000 fully loaded

• Senior: £75,000-£110,000/year + on-costs = £97,000-£143,000 fully loaded

Freelance (UK-based)

• £400-£700/day depending on seniority and availability

• No employment overhead but no continuity, management burden on you, and the best freelancers are typically booked

Dedicated remote via staff augmentation (vetted talent)

• Junior: £1,200-£2,000/month

• Mid-level: £2,000-£3,500/month

• Senior: £3,000-£5,000/month

The staff augmentation model at those rates represents a 60-70% cost saving versus equivalent UK employment — not because the developer is inferior, but because the cost of living differential between the UK and other countries is significant, and you're not paying for London overheads, employer NI, pension contributions, or recruitment fees.

The critical qualifier: those numbers assume genuine quality control. A cheap developer who produces unchallengeable code is not a saving — it's a liability that compounds. The vetting process, the ongoing management quality, and the AI-bootcamp training that gets developers to operating standard quickly are what make the cost difference commercially sensible rather than just cheaper.

According to Stack Overflow's 2025 survey, 84% of developers now use AI tools daily. Around 41% of all code written in 2025 is AI-generated in some form. The question isn't whether your Java developer uses AI — they almost certainly will. The question is whether they use it effectively.

A Java developer who understands how to leverage AI coding assistants — prompt engineering for code generation, AI-assisted code review, automated test generation, intelligent debugging — operates meaningfully faster than one who doesn't. The output isn't different in kind, but the volume and speed of delivery is substantially higher.

What to ask in interviews:  

• How do you currently use AI tools in your development workflow?

• What does prompt engineering for code generation look like for you?

• How do you validate AI-suggested code before committing it?

The answers will immediately tell you whether you're talking to someone who occasionally uses Copilot for autocomplete, or someone who has genuinely integrated AI into their working practice. The second type is worth more.

This is, incidentally, one of the things Octogle specifically trains for. Every developer we place goes through our proprietary AI bootcamp before touching a client project — not as a checkbox, but as intensive training in how to actually extract value from AI tooling at every stage of the development cycle. The result is developers who arrive operating at a level that most traditional hires take six to twelve months to reach.

LinkedIn

The obvious starting point and an imperfect one. The best Java developers are rarely actively job-hunting — they're employed and comfortable. Reaching them requires either a very compelling opportunity or a very persistent recruiter. LinkedIn is good for building a pipeline. It's slow.

Developer communities and forums

‍Java-specific Slack groups, GitHub profiles, Stack Overflow contributions, technical blogs — developers who are actively engaged in the community beyond their job are often the most current and most motivated. Finding them requires effort but produces higher-quality conversations.

Specialist technical recruitment agencies

‍With deep networks and pre-screening capabilities, they save time at the top of the funnel. They also charge 15-25% of first-year salary as a fee, which on a senior Java developer hire is a significant additional cost on top of an already significant salary.

Staff augmentation partners

‍For companies looking to scale a Java development capability without the overhead and timeline of permanent hiring, staff augmentation provides pre-vetted, embedded developers within weeks rather than months. Octogle specifically operates this model — sourcing from India's talent pool, putting every developer through multi-stage technical vetting and our AI bootcamp, and embedding them directly into client teams within two weeks of engagement.

For freelance/contract work

‍Toptal (rigorous vetting, higher cost), Upwork (broad pool, highly variable quality, requires significant vetting effort on your side), and specialist developer marketplaces.

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The right channel depends on your timescale, your budget, and whether you need permanent headcount or flexible capacity. Most growing companies find that the fastest, most cost-efficient route to a capable Java developer on their team is not the traditional UK hiring market.

If you're a CTO, VP of Engineering, or technical co-founder who needs to extend your Java development capacity without the overhead, timeline, or cost of UK-based hiring — this is precisely what we do.

We source Java developers from our international talent network, put them through a multi-stage vetting process (technical assessments, coding challenges, communication evaluation, AI bootcamp), and embed them directly into your team within two weeks.  

They attend your standups, use your tooling, operate in overlapping time zones, and function as extensions of your existing team — not as outsourced strangers throwing code over a wall.

Monthly retainer model. Instant replacement guarantee if a developer doesn't work out. Ongoing management, HR, equipment, and support handled by us. You manage the day-to-day work.

If you're scaling a Java team and want to do it efficiently — let's have a conversation about what that looks like for your specific stack and team structure.