Job description template

JavaScript Developer

As a Mid-level JavaScript Developer, you’ll build and maintain user-facing and internal web applications, delivering reliable features through the full development lifecycle. You’ll work independently on well-defined work while collaborating with product and engineering peers to improve performance, reliability, and developer experience.

Responsibilities

Develop features in JavaScript/TypeScript for web applications and services
Write maintainable, testable code following established engineering standards
Collaborate with designers and backend engineers to integrate APIs and data flows
Diagnose and resolve bugs across the frontend and/or Node.js layers using logs and observability signals
Improve application performance and reliability through profiling and targeted refactors
Create and maintain automated tests to prevent regressions and ensure consistent releases
Document changes and contribute to code reviews and technical discussions

Must-have qualifications

Hands-on experience building production web applications with JavaScript and/or TypeScript
Working knowledge of modern frontend patterns (e.g., component-based UI, state management, client-side routing)
Practical experience with Node.js (APIs, middleware, and asynchronous programming)
Experience writing automated tests (unit and/or integration) for JavaScript/TypeScript codebases
Strong understanding of HTTP, REST/JSON, and common web security considerations
Experience using Git and collaborating via pull requests in a team environment

Nice to have

Experience with React or similar component frameworks
Familiarity with CI pipelines and code quality tooling (linting, formatting, testing)
Experience with performance debugging (browser profiling, server-side profiling)
Experience with observability tooling (logging/metrics/tracing)

What success looks like in 12 months

Feature delivery on well-defined work
Reliability and bug reduction
Quality through automated testing
Performance and responsiveness improvements
Maintainable code and low review friction

Logistics

Full-time (40 hours a week), remote from Latin America.
Working hours overlap with US business hours.

About the company

[About your company: what you build, your stage and team size]

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Interview scorecard

Score every candidate against the same bar

Deliver reliable JavaScript/TypeScript features that improve product functionality, performance, and maintainability in a production environment.

Outcomes to measure

What this hire should deliver in the first year. Replace [N] with your own targets.

Feature delivery on well-defined work. Measure: Ship [N] features and complete [X]% of planned work items within agreed scope and timelines
Reliability and bug reduction. Measure: Reduce production issues/incidents attributable to your changes by [X]%
Quality through automated testing. Measure: Increase test coverage for touched areas by [X]% and maintain/raise pass rate of relevant test suites to [X]%
Performance and responsiveness improvements. Measure: Improve key performance metric(s) by [X]% (e.g., page load time, API latency, or core web vitals) for at least [N] critical user flows
Maintainable code and low review friction. Measure: Maintain review outcomes of [X]% of PRs merged without major rework requests and keep PR cycle time within [X] days (median)

Competencies and weights

What to evaluate, how much it counts and what a strong answer looks like.

JavaScript and TypeScript · 28%
Core ability to deliver correct, maintainable features in the primary language ecosystem. Evaluated in Round 1.

Weak: Troubleshoots basic language/runtime issues slowly and struggles to reason about async behavior and types.
Meets the bar: Writes clear JS/TS code, handles async flows correctly, and uses types to reduce defects.
Strong: Proactively designs robust code with strong type modeling, clear module boundaries, and predictable async control flow.

Frontend architecture patterns · 18%
Ensures delivered UI work is maintainable and consistent with modern frontend practices. Evaluated in Round 1.

Weak: Implements UI changes without clear state/data flow; introduces brittle components or tangled event handling.
Meets the bar: Builds component-based UI with coherent state management and clear separation of concerns.
Strong: Designs and refactors UI flows for scalability, minimizing side effects and improving user experience performance.

Node.js API development · 18%
Needed to implement and integrate backend-facing capabilities and reliable async server behavior. Evaluated in Round 2.

Weak: Misunderstands request/response lifecycles, leading to incorrect API behavior or inefficient async handling.
Meets the bar: Implements Node.js routes/middleware correctly, handles errors and async operations reliably.
Strong: Builds well-structured APIs with resilient error handling, input validation, and efficient concurrency patterns.

Testing and verification · 14%
Prevents regressions and increases confidence in releases. Evaluated in Round 2.

Weak: Relies mostly on manual testing; tests are missing or hard to maintain.
Meets the bar: Creates practical unit/integration tests and ensures they run reliably in the normal workflow.
Strong: Chooses high-value test strategies, writes stable tests, and uses testing to guide design improvements.

Web fundamentals security · 10%
Reduces risk by applying correct HTTP semantics and basic security practices. Evaluated in Round 3.

Weak: Confuses HTTP methods/status codes or overlooks common security pitfalls in client/server interactions.
Meets the bar: Applies correct HTTP/REST conventions and uses appropriate safeguards (e.g., input handling, auth/headers concepts).
Strong: Anticipates edge cases and mitigates security risks through thoughtful validation and safe patterns.

Code collaboration and PR quality · 7%
A mid-level developer must collaborate effectively and maintain code quality through reviews. Evaluated in Round 3.

Weak: Needs frequent clarification during review and provides little context or follow-up.
Meets the bar: Writes clear PR descriptions, responds to feedback constructively, and keeps changes focused.
Strong: Improves team outcomes through proactive review hygiene, thoughtful tradeoffs, and clear communication.

Ownership and debugging · 5%
Independent execution and effective troubleshooting are key for success on well-defined work. Evaluated in Round 2.

Weak: Waits for others to debug common issues and struggles to form hypotheses from available evidence.
Meets the bar: Uses logs/metrics and structured reasoning to debug; closes issues by implementing and validating fixes.
Strong: Leads root-cause analysis, identifies contributing factors, and prevents recurrence with targeted improvements.

Interview questions

Questions for every interview round

Each round has an owner, a time box and questions that test the competencies above.

Round 1: Frontend & JavaScript depth
Senior Frontend Engineer · 45 min

Walk through a production JavaScript/TypeScript feature you built end-to-end: what was the data flow, state management approach, and key decisions?
Describe how you handle async behavior in the browser (e.g., fetch flows, retries, cancellation). What bugs have you seen and how did you prevent them?
How do you structure UI components to keep state and side effects manageable? Give an example of a refactor you performed to reduce complexity.
In a single-page app, how would you reason about client-side routing and error states (loading, empty, error)?

Round 2: Node.js & testing
Backend Engineer · 45 min

Describe a Node.js API you implemented or maintained. How did you handle request validation, errors, and asynchronous work?
How do you test async code in Node.js (e.g., timing, promises, and side effects)? What makes a test reliable in practice?
Give an example of a bug you debugged in a Node.js service using logs/observability. What evidence did you use and what was the root cause?
What is your approach to choosing between unit vs integration tests for a feature?

Round 3: Web fundamentals, security & collaboration
Engineering Manager · 40 min

Explain HTTP semantics: when would you use different status codes, and how do you ensure clients handle them correctly?
What are common web security risks in typical frontend/backend interactions (e.g., XSS/CSRF/injection-related concerns)? How do you mitigate them in day-to-day coding?
Describe a time your PR was reviewed with requested changes. What did you change, how did you respond, and what did you learn?
How do you document and communicate tradeoffs during implementation to keep a team aligned?

Red flags to watch for

Frequently unable to explain async behavior (promises, async/await, cancellation) or gives inconsistent answers about how code executes in production.
Tests are minimal or unreliable (e.g., brittle timing-based tests) and the candidate cannot justify testing strategy choices.
Confuses HTTP fundamentals (methods, status codes, request/response lifecycle) or proposes unsafe/incorrect patterns without acknowledging security implications.
Lack of ownership in debugging—depends on others for root cause or cannot describe how evidence led to the fix.

How much does it cost to hire a JavaScript Developer in Latin America?

In 2026, a senior JavaScript Developer in Latin America costs $6,750 to $7,750 a month all-in, versus $14,625 in the US: up to 54% less. Mid-level starts at $4,500.

Country

Mid-level

Senior

Argentina

$4,500

$6,750

Brazil

$5,000

$7,500

Colombia

$4,500

$6,750

Mexico

$5,250

$7,750

United States

$11,875

$14,625

Monthly cost in USD, all-in: the talent's salary plus Teilur's flat 20% fee, from our 2026 rates. The United States row shows what the same role typically costs there.

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JavaScript Developer Job Description Template