JavaScript Expert Training - Master ESNext and Performance

Very demanding course · Expertise required

$7,875

  • 5 days
  • Onsite
  • 10 people max.
Ref: JEG370
10 people max.
$7,875
In-company rate: from $14,175 for the whole teamExpertise rate: $1,575 per day, reflecting the difficulty level
On-site and certification exam on quote
5 days
Onsite

Don't let this gap widen

Why this program matters

  • Without ESNext mastery, your JS apps lose 40% in performance, memory leaks crash 25% of mobile users, poorly managed async causes 35% production bugs according to Stack Overflow.

  • Obsolescence against Deno/Bun ejects 20% junior devs from the market (Indeed 2024).

  • Loss of competitiveness: frameworks like Next.js require experts, otherwise -30% average salary (Glassdoor).

  • Avoid costly downtime (500k€/major incidents), OWASP hacks draining client data, and team turnover from blockages.

  • Invest 35h to dominate, or risk relegation against agile competitors.

Célian Lebacle, Learni trainer · Web & mobile expert
Célian Lebacle

Learni trainer · Web & mobile expert

73%productivity gap
×3cost of inaction
Flag of the United StatesBuilt for US teams
Payment by wire transferEnhanced confidentialityPerfect for companies with 50 to 500 employeesScheduling to fit any time zone

Trusted by — schools, companies and industrial groups

41,305 programs · 25 countries

  • Aptar
  • ArcelorMittal
  • Equans
  • EDF
  • Ubisoft
  • Microsoft
  • Atos

Every program built with a dedicated engineer

  • OpenAI
  • Anthropic
  • Mistral AI
  • NVIDIA
  • Google
  • Amazon Web Services
  • Microsoft Dynamics 365
  • Salesforce
  • ServiceNow
  • SAP
  • Oracle
  • Cisco
  • Fortinet
  • Palo Alto Networks
  • Aruba
  • VMware
  • Red Hat
  • Databricks
  • Snowflake
  • OVHcloud
  • Notion
  • AMD
  • Apple

Companies: Aptar, ArcelorMittal, Equans, EDF, Ubisoft, Microsoft and Atos.

JavaScript Expert training objectives

  • Master ES6+ and ESNext for modern and concise code
  • Optimize performance with profilers and Web Workers
  • Implement async/await and generators without blocking
  • Manage advanced modules and bundlers like Webpack and Vite
  • Develop design patterns and advanced TDD tests
  • Secure JS applications against OWASP vulnerabilities

Program

JavaScript Expert curriculum: 5 modules over 5 days

Module 1 : ES6+ and ESNext: arrows, destructuring, classes (Node, Babel)

Dive into modern syntaxes, refactor legacy code in practical exercises on Node replays, build extended classes with inheritance, test proxies and symbols in real API cases, produce a functional ESNext module ready for production, gaining immediate fluency and power.

Module 2 : Advanced Asynchronous: promises, async/await, generators (fetch API)

Master async flows without callback hell via workshops on fetch and REST APIs, implement generators for infinite iterators, debug race conditions in real simulations, generate a live data dashboard with await, feel the simplicity that boosts your productivity from tomorrow.

Module 3 : Modules and Bundlers: ESM, Webpack, Vite (tree-shaking)

Configure dynamic imports and tree-shaking in collaborative projects, bundle complex apps with Vite for ultra-fast deployments, migrate CommonJS to native ESM, optimize vendor chunks in e-commerce cases, leave with a zero-config personal bundler ready to scale.

Module 4 : JavaScript Performance: profilers, Workers, memory (Chrome DevTools)

Profile memory leaks and bottlenecks with DevTools in live challenges, parallelize heavy tasks via Web Workers, minify and lazy-load assets in a real app, measure gains up to 50% speed, deliver a complete perf audit, transform your slow apps into competitive rockets.

Module 5 : Advanced Patterns and Tests: TDD, Jest, security (OWASP Top10)

Apply Observer, Module, and Factory in expert refactorings, test with Jest and advanced mocks on microservices, secure against XSS and injections via hack-proof workshops, finalize a certified project portfolio, integrate these skills to lead your teams to excellence.

How JavaScript Expert skills are assessed

  • Interactive quizzes and daily coding challenges
  • Final personal project with expert feedback
  • Qualiopi certification on acquired skills

How the JavaScript Expert course is taught

  • Hands-on method with 70% practical live coding
  • Replayable digital materials and cheat sheets
  • Real-world cases inspired by Fortune 500 production

JavaScript Expert training: access and practical arrangements

The JavaScript Expert Training - Master ESNext and Performance program is delivered onsite or remote (blended-learning, virtual classroom, remote presence). At Learni, an industry-certified training organization, every program is built to maximize skills acquisition regardless of the chosen format.

The trainer alternates between demonstrative, interrogative and active methods (through hands-on labs and/or scenarios). This pedagogical approach guarantees concrete learning that's immediately applicable at work.

Equipment required

For the smooth delivery of the JavaScript Expert Training - Master ESNext and Performance program, the following equipment is required:

  • Mac or PC computers, high-speed fiber internet, whiteboard or flipchart, projector or interactive touch screen (for remote sessions)
  • Training environments installed on workstations or accessible online
  • Course materials, hands-on exercises and complementary resources
  • Post-training access to materials and educational resources

For intra-company training on a site outside Learni, the client commits to providing all required teaching materials (computers, internet, etc.) for the smooth delivery of the program in line with the prerequisites in the communicated program.

* contact us for remote delivery feasibility** ratio varies depending on the program

Skills assessment methods

Assessment of skills acquired during the JavaScript Expert Training - Master ESNext and Performance program is performed through:

  • During training: case studies, hands-on labs and professional scenarios
  • End of training: self-assessment questionnaire and skills evaluation by the trainer
  • After training: completion certificate detailing acquired skills

Program accessibility

Learni is committed to making its programs accessible. All our programs are accessible to people with disabilities. Our teams are available to adapt the pedagogical methods to your specific needs. Please contact us for any adjustment request.

Enrollment terms and lead times

Registration is possible up to 48 business hours before the start of training. All our programs are built for corporate L&D budgets and delivered onsite or remotely.

The Learni story

Founded by engineers and learning experts, Learni's mission is to make high-impact tech training accessible to teams everywhere. We work remotely with organizations across the US and Canada, in your time zone, to help teams upskill fast.

Our method

How Learni guarantees the quality of your JavaScript Expert training

Before, during, after: we frame the brief, introduce the trainer, tailor the content and measure impact. You stay in control from kickoff to wrap-up.

Step 1

Rigorous trainer selection

Each trainer is validated on three criteria: hands-on field expertise, proven pedagogy and alignment with your industry.

  • Triple validation: technical, pedagogical, sectoral.
  • Minimum rating 4.8/5 over the last 12 sessions.
Step 2

You meet the trainer beforehand

30-minute video call between you and the selected trainer to validate the fit, adjust content and clear any final doubts.

  • Live briefing on goals and team context.
  • Veto right — we swap the trainer for free if needed.
Step 3

Content tailored to your context

No recycled slides. The syllabus is reworked from your real cases: tools, constraints, vocabulary, ongoing projects.

  • Hands-on cases drawn from your stack and projects.
  • Program co-written then validated by your team.
Step 4

Continuous quality follow-up

Live evaluations, 30/90/180-day check-ins and a consolidation plan. If the impact misses the mark, we rework it.

  • NPS, knowledge quizzes and skills self-assessment.
  • Satisfaction guarantee: fully satisfied or free rework.

A simple promise: you don't pay to discover the trainer on day one. Everything is validated upfront, by you.

A child walking to school with a backpack
Our social commitment

A school kit donated to a child for every training booked

To fight inequalities in access to education, Learni donates a complete school kit to a child in need for every training booked. You build your skills, a child heads back to school.

  • Backpack, notebooks and essential supplies
  • Distributed through our partner charities
  • Included, at no extra cost to you
Enroll and offer a kit
FAQ

JavaScript Expert: frequently asked questions

Which tools are used in JavaScript Expert Training training?+
Hands-on work runs on node, babel, fetch API, tree-shaking, chrome DevTools and OWASP Top10. Those tools come from the JavaScript Expert Training program itself, delivered on site over 5 days, so participants practise on the stack they will use at work.
What can participants do after JavaScript Expert Training training?+
They can master ES6+ and ESNext for modern and concise code, optimize performance with profilers and Web Workers and implement async/await and generators without blocking. Those are the stated objectives of the JavaScript Expert Training program at Expert level, checked by the end-of-session assessment.
What does the JavaScript Expert Training program cover, day by day?+
Day 1: ES6+ and ESNext: arrows, destructuring, classes (Node, Babel). Day 2: Advanced Asynchronous: promises, async/await, generators (fetch API). Day 3: Modules and Bundlers: ESM, Webpack, Vite (tree-shaking). Day 4: JavaScript Performance: profilers, Workers, memory (Chrome DevTools). Day 5: Advanced Patterns and Tests: TDD, Jest, security (OWASP Top10). The JavaScript Expert Training program runs over 5 days, delivered on site.
How is JavaScript Expert Training training assessed?+
Assessment relies on interactive quizzes and daily coding challenges, final personal project with expert feedback and qualiopi certification on acquired skills. Learni issues a completion certificate together with the individual assessment report at the end of the JavaScript Expert Training program, which an L&D team can file as evidence.
How much does JavaScript Expert Training training cost per participant?+
JavaScript Expert Training training costs $7,875 per participant. For an in-company team, the flat rate starts at $14,175 for the whole group, up to 8 people. The detailed quote, sent within one business day, adjusts the amount to the format and how far the syllabus is tailored to your team.
How long does JavaScript Expert Training training take?+
5 days, available live online (US time zones) or on-site at your offices. Half-day tracks spread over several weeks are possible so the team stays operational.
Who pays for JavaScript Expert Training training?+
Most US teams pay directly through their company L&D or training budget. Learni invoices in US dollars and accepts bank transfer (ACH/wire) or card, with volume pricing for teams. A purchase order is welcome.
What do participants need to know before JavaScript Expert Training training?+
Expert mastery of JavaScript ES5, experience with Node.js or React/Vue frameworks, minimum 3 years in production.
Is a certificate issued after JavaScript Expert Training training?+
Yes. A Learni completion certificate is issued, along with the individual evaluation report. Learni is a certified training provider and prepares for third-party certifications, but does not award them itself.
Does Learni provide the equipment for JavaScript Expert Training training?+
No. A computer and a stable internet connection are required for each participant. Learni provides the learning platform, the trainer and all course materials.
Your professional training, anywhere

Let's build your JavaScript Expert learning path.

30 minutes with a learning advisor. No commitment. No sales pitch dressed up as a demo.

Reply within 24h · Vetted experts · USD invoicing · W-9 available
On-site & remote

JavaScript Expert training in your city

Available on-site and remotely. Pick your city to see the local training center.

Share in 2 clicks