Full Stack Developer Job Description: Responsibilities, Skills, Interview Questions and Monthly Cost
A clear full stack developer job description saves you weeks of mismatched interviews. Most bad hires in this role come from a vague brief: the posting asks for everything, the candidate is strong at half of it, and nobody noticed until the first sprint.
This guide covers what the role actually involves, when it is the right hire, which skills to test, how to interview, and what it costs per month. A template you can adapt is at the end.
What a full stack developer does day to day
A full stack developer ships features end to end, from the database and API through to the screen the user sees. They are not an expert in every layer. They are someone who can carry a feature from ticket to production without waiting for three other people.
A typical week includes:
- Building or changing user interface components and wiring them to real data.
- Designing and writing API endpoints, including validation, authentication and error handling.
- Modelling data, writing migrations and tuning slow queries.
- Writing automated tests at the unit, integration and end-to-end level.
- Reviewing pull requests and responding to review comments on their own.
- Helping with deployment, logs and production issues after a release.
- Talking to product and design about what is feasible and what it costs in time.
The last point matters more than most descriptions admit. A strong full stack developer pushes back on scope, proposes a smaller first version and explains trade-offs in plain language.
When a full stack developer is the right hire (and when it is not)
A full stack developer is the right hire when your product needs steady feature delivery across the whole application and you do not yet have deep specialist workloads.
They fit well when:
- You are building or extending a web product with a small team and need one person to move a feature all the way through.
- Your back end is mostly standard work: APIs, a relational database, background jobs and third-party integrations.
- You want fewer handoffs. One person who understands both sides of a feature avoids the gaps that appear between separate front-end and back-end tickets.
- You are validating a product and need to change direction quickly.
They are a weaker fit when:
- The hard problem is specialist. Heavy data pipelines, complex real-time systems, security-critical code or intricate design systems usually need someone who spends all their time in that area.
- Your front end is a large, design-led product where interaction polish and accessibility are the main differentiator.
- Your platform already has a large back end with strict performance needs and you only need more capacity there.
In those cases, hire the specialist, or pair a full stack developer with one. A generalist next to a specialist is often the most efficient setup for a growing product.
Skills to test for a full stack developer, including Node.js on the back end
Test depth in one language and one stack, plus working competence across the rest, because nobody is equally strong everywhere.
Most teams hiring for JavaScript or TypeScript products will want Node.js on the back end, paired with a modern front-end framework such as React, Vue or Angular. Whatever your stack, decide which layer is your priority and weight the evaluation accordingly.
| Area | What to test | Signs of real experience |
|---|---|---|
| Front end | Component design, state management, accessibility basics, browser behaviour | Explains why state lives where it does; knows what causes unnecessary re-renders |
| Back end (for example Node.js) | API design, async behaviour, error handling, authentication | Understands the event loop, avoids blocking calls, handles failures deliberately |
| Databases | Schema design, indexes, transactions, query tuning | Reads a query plan; knows when a migration is risky |
| Testing | Test strategy, mocking boundaries, end-to-end coverage | Tests behaviour, not implementation details |
| Delivery | Git workflow, CI, deployment basics, logging | Has fixed a production issue and can describe what they changed afterwards |
| Communication | Written updates, estimates, pushing back on scope | Gives clear, short answers and flags risk early |
A practical way to use this table: pick your two or three must-haves, mark the rest as trainable, and say so in the job post. Candidates respond well to honesty about priorities.
How to interview a full stack developer: questions and what good answers look like
The best interview for this role mixes a few focused questions with one realistic exercise, and listens for reasoning rather than recited definitions.
1. Walk me through the last feature you shipped from database to UI. Good answers name specific decisions: how the data was modelled, what the API contract looked like, what went wrong and what they would change. Be wary of answers that only describe one layer.
2. How would you design an API endpoint that lists a large set of records? Good answers cover pagination, filtering, indexes, consistent response shapes and what happens when the dataset grows. Bonus if they ask how the data is used before answering.
3. A page is slow. Where do you start? Strong candidates measure first. They separate network time, server time, database time and rendering time before changing anything. Weak answers jump to a fix.
4. How do you handle authentication and authorisation in a web app? Look for a clear difference between the two, sensible handling of sessions or tokens, and awareness of common mistakes such as trusting client-side checks.
5. Tell me about a bug that only appeared in production. Good answers show calm method: reproduce, narrow down, fix, add a test, and improve logging so the next one is easier.
6. What do you test, and what do you leave untested? The right answer is a judgement, not a slogan. Good candidates test the parts where failure is costly and keep tests resilient to refactoring.
7. How do you tell a stakeholder that a feature will take longer than expected? Listen for early warning, options with trade-offs and a smaller first slice. This question separates people who deliver from people who only code.
For the exercise, give a small, real task: add an endpoint and a screen that uses it, in a repository you provide. Ask them to explain their choices afterwards. A review of their code with you often tells you more than any quiz.
What a full stack developer costs per month, all-inclusive
A full-time full stack developer typically costs between $2,500 and $4,900 per month all-inclusive for mid-level and senior engineers, and more for lead roles.
On Dev-Hire, you pay one all-inclusive monthly rate per engineer. It covers the engineer, payroll, benefits, equipment, free replacement and our fee. There are no setup or placement fees, and the engagement is month to month.
| Level | Typical full-time monthly rate (all-inclusive) |
|---|---|
| Mid-level | $2,500 to $3,700 |
| Senior | $3,500 to $4,900 |
| Lead or architect | $4,900 to $6,900 |
Part-time engagement is half of the full-time monthly rate. Where you land in each range depends on seniority, the breadth of the stack and how specialised the work is.
Every engineer is vetted through a profile review, a communication check and a technical interview by a senior engineer, and only the top 1.5% of applicants are accepted. You get a shortlist in 48 hours and can start within a week. Engineers work your hours with a stated daily overlap, so standups and code reviews happen in real time. You can browse the role on the full stack developer hiring page.
Dedicated full stack developer or a wider team: choosing how to work
Choose one dedicated engineer when the work fits one person, and move to a team when delivery depends on several skills at once.
There are four ways to work with Dev-Hire:
- One engineer: best for a clear backlog, a product that needs steady feature work, or filling a gap in your existing team.
- A dedicated team of 2 to 10 engineers: best when you need, for example, two full stack developers plus a QA engineer or a DevOps specialist. The team builder helps you size this.
- A managed team with a Dev-Hire delivery lead: best when you want someone accountable for planning and day-to-day delivery without adding management load for yourself.
- A scoped software project: best when you have a defined outcome and prefer a fixed scope to managing people.
A useful rule: if you have a technical lead who can set priorities and review code, a single engineer or a dedicated team works well. If you do not, a managed team usually saves you more time than the extra cost of coordination.
A simple job description template you can adapt
Keep the job description short, specific and honest about priorities, so the right people can recognise themselves in it.
Title: Full Stack Developer (mid-level or senior)
About the role: We are looking for a full stack developer to own features end to end in [product name or short description]. You will work with [product manager, designer, other engineers] and join our daily standup during [overlap hours].
Responsibilities:
- Build and maintain features across the front end, API and database.
- Write automated tests and review teammates' code.
- Investigate and fix production issues, and improve logging and monitoring.
- Estimate work honestly and raise risks early.
Must have:
- Solid experience with [primary language, for example TypeScript] and [front-end framework].
- Back-end experience with [for example Node.js] and a relational database.
- Comfort with Git, code review and CI.
- Clear written English and the ability to work with our overlap hours.
Nice to have:
- Experience with [cloud platform, queue, cache or other tool you use].
- Experience in [your domain].
How we hire: a short conversation, a technical interview and a small practical exercise. We aim to decide within [number] days.
Swap the bracketed parts for your own stack and trim anything you would not actually test. A shorter list of real requirements attracts better candidates than a long wish list.
Ready to see what this looks like for your stack? Use the cost calculator on Dev-Hire pricing to get your all-inclusive monthly figure.
